Canadian Economic and Emissions Model for
Agriculture (C.E.E.M.A. Version 1.0)
Report 1: Model Description
April 1999
CANADIAN ECONOMIC AND
EMISSIONS MODEL FOR
AGRICULTURE
(C.E.E.M.A. Version 1.0)
Report 1: Model Description
Agriculture and Agri-Food Canada
April 1999
CANADIAN ECONOMIC AND EMISSIONS MODEL FOR AGRICULTURE
(C.E.E.M.A. Version 1.0)
Report 1: Model Description
S.N. Kulshreshtha, Professor, Agricultural Economics
University of Saskatchewan, Saskatoon
Marc Bonneau, Acting Head, Economics Section, Prairie Farm Rehabilitation Administration
Agriculture and Agri-Food Canada, Regina
Marie Boehm, Associate Director (Environment)
Center for Studies in Agriculture, Law, and the Environment, University of Saskatchewan, Saskatoon
John C. Giraldez, Economist, Economic and Policy Analysis Directorate, Policy Branch
Agriculture and Agri-Food Canada, Ottawa
This publication was made possible by way of contract between its authors and Agriculture and
Agri-Food Canada. Because of its technical nature, it is available only in the language of the
author.
Any policy views, whether explicitly stated, inferred or interpreted from the contents of this
publication, should not be represented as reflecting the views of Agriculture and Agri-Food
Canada.
Economic and Policy Analysis Directorate
Policy Branch
April 1999
To obtain additional copies, contact:
Information Production and Promotion Unit
Economic and Policy Analysis Directorate
Policy Branch
Agriculture and Agri-Food Canada
Ottawa, Ontario
K1A 0C5
Tel: (613) 759-7443
Fax: (613) 759-7034
E-mail: [email protected]
Electronic versions of EPAD publications are available on the Internet at www.agr.ca/policy/epad.
ISBN 0-662-27641-8
Catalogue A22-185/1999E
Publication 1993/E
Project 99024tp
Contract 01B04-6-C096 (Dept. Rep.: Bruce Junkins)
Table of Contents
Foreword ....................................................................................................................... xiii
Executive Summary...................................................................................................... xv
Acknowledgements .................................................................................................... xvii
Chapter 1: Introduction ................................................................................................... 1
1.1
1.2
1.3
1.4
1.5
1.6
Background .................................................................................................................... 1
Importance of Agricultural Emissions of Greenhouse Gases ................................. 3
1.2.1 Global Emissions................................................................................................ 3
1.2.2 Canadian Emissions .......................................................................................... 4
Need for the Study ........................................................................................................ 5
Objectives of the Study ................................................................................................. 6
Scope of the Study ......................................................................................................... 7
Organization of the Report .......................................................................................... 7
Chapter 2: Linkages Between Agricultural Production Activities
and Emission of Greenhouse Gases
2.1
2.2
2.3
2.4
9
Sources of Major Greenhouse Gases Emissions at the Global Scale ...................... 9
2.1.1 Carbon dioxide................................................................................................... 9
2.1.2 Methane............................................................................................................. 11
2.1.3 Nitrous Oxide................................................................................................... 12
Effects of Environmental and Management Factors .............................................. 13
Factors Affecting Emission Levels from Agricultural Activities.......................... 15
2.3.1 Factors Affecting Emissions from Crop Production................................... 15
2.3.2 Factors Affecting Emissions from Livestock Production........................... 18
Summary....................................................................................................................... 19
Chapter 3: Analytical Framework ............................................................................... 21
3.1
3.2
3.3
3.4
3.5
Review of Previous Studies........................................................................................ 21
Considerations Involved in the Development of the GHGE Sub-Model............ 22
3.2.1 Scope of Agriculture Production Activities ................................................. 22
3.2.2 Considerations in the Design of the Model ................................................. 23
Conceptual Method of Estimation ............................................................................ 23
3.3.1 Conceptual Linkages between Agricultural Production
Activities and Emissions................................................................................. 24
3.3.2 Specification of Linkages ................................................................................ 25
3.3.3 Estimation of Agriculturally-Induced Emission Levels............................. 28
Specification of GHGE Sub-Model ........................................................................... 32
3.4.1 Specification of Regions .................................................................................. 32
3.4.2 Specification of Production Activities .......................................................... 33
Overview of the Integrated Model............................................................................ 33
Canadian Economic and Emissions Model for Agriculture: Report 1
Table of Contents
Chapter 4: Methodology for the Estimation of Emission Coefficients................... 35
4.1
4.2
Emission Coefficients for Crop Production.............................................................
4.1.1 Carbon Dioxide................................................................................................
4.1.2 Nitrous Oxide ..................................................................................................
Greenhouse Gases Emission Coefficients for Livestock Production...................
4.2.1 Carbon Dioxide................................................................................................
4.2.2 Methane ............................................................................................................
4.2.3 Nitrous Oxide ..................................................................................................
35
36
47
49
49
54
56
Chapter 5: Results for the Base Scenario..................................................................... 61
5.1
5.2
5.3
5.4
5.5
Agricultural Activity in the Base Year (1994) .........................................................
Accounting Framework for Agricultural Emissions .............................................
Agricultural Activities as a Source of Greenhouse Gas Emissions......................
5.3.1 Estimated Total Emission Levels ..................................................................
5.3.2 Distribution of Total Emissions by Activity................................................
5.3.3 Distribution by Regions..................................................................................
Total Emissions of (Non-CO2-equivalent)...............................................................
5.4.1 Carbon Dioxide................................................................................................
5.4.2 Methane ............................................................................................................
5.4.3 Nitrous Oxide ..................................................................................................
5.4.4 Comparison of Results with Other Studies .................................................
Regional Distribution .................................................................................................
61
63
65
66
66
67
69
69
69
69
69
74
Chapter 6: Estimation of Greenhouse Gas Emissions for Selected Scenarios ....... 75
6.1
6.2
6.3
Study Scenarios ...........................................................................................................
6.1.1 Selection of Study Scenarios ..........................................................................
6.1.2 Description of Study Scenarios .....................................................................
Results for Increase in No-Till System Scenario .....................................................
Results for Livestock Expansion ...............................................................................
6.3.1 Emissions in CO2-equivalent Levels.............................................................
6.3.2 Individual Greenhouse Gases .......................................................................
6.3.3 Regional Distribution of Emissions Levels..................................................
75
75
76
79
82
82
83
85
Chapter 7: Summary and Future Research Areas ..................................................... 89
7.1
7.2
7.3
Summary ...................................................................................................................... 89
Major Conclusions ...................................................................................................... 91
Areas for Future Research ......................................................................................... 92
References ....................................................................................................................... 95
Appendix A: Specification of Regions and Production Activities
in C.E.E.M.A. ....................................................................................... A-1
Appendix B: Comparison of Soil Carbon Loss by Provinces................................ B-1
Appendix C: Results of Regression Analysis ......................................................... C-1
Appendix D: Details on Selected Crop Inputs by Provinces................................ D-1
Appendix E: Emissions of Greenhouse Gases by Provinces and Activities ....... E-1
Canadian Economic and Emissions Model for Agriculture: Report 1
List of Tables
1.1
1.2
1.3
2.1
2.2
2.3
2.4
2.5
2.6
2.7
2.8
3.1
3.2
4.1
4.2
4.3
4.4
4.5
4.6
4.7
4.8
4.9
4.10
4.11
4.12
4.13
4.14
4.15
An Overview of Greenhouse Gases Emissions Affected by
Anthropogenic Activities ............................................................................................ 2
Contribution of Agriculture to Greenhouse Gas Emissions,
by Type of Gas, Global and Canada .......................................................................... 5
Estimates of Greenhouse Gases Emissions from Agricultural
Activities, Canada, 1991............................................................................................... 5
Major Sources of Global Emissions of Carbon Dioxide,
Annual Flux, Average 1980 to 1999 ......................................................................... 10
Major Sources of Global Emissions of Methane, Annual Levels......................... 11
Major Sources of Global Emissions of Nitrous Oxide, Annual Levels ............... 13
Linkages between Emissions of Greenhouse Gases and Activities
Related to Agriculture................................................................................................ 14
Factors Affecting Carbon Dioxide Emissions from Crop Production
Practices........................................................................................................................ 16
Factors Affecting Methane Emissions from Crop Production Practices ............ 17
Factors Affecting Nitrous Oxide Emissions from Crop Production
Practices........................................................................................................................ 18
Factors Affecting Methane Emissions from Animal Production Practices ........ 19
Conceptual Linkages between Emissions of Greenhouse Gases and
Crop Production Activities........................................................................................ 26
Conceptual Linkages between Emissions of Greenhouse Gases and
Livestock Production Activities................................................................................ 29
Input Data for the Estimation of Emission Coefficients for
Photosynthesis by Crops .......................................................................................... 37
Level of Soil Carbon Loss (from 0-30 cm depth) to the Atmosphere
from Cultivation of Crops, Canada ........................................................................ 38
Level of Soil Carbon Loss (from 0-30 cm depth) to the Atmosphere
by Soil Type, Canada ................................................................................................. 38
Level of Carbon Dioxide Released into the Atmosphere Related
to Direct Use of Fossil Fuels ...................................................................................... 42
Level of Carbon Released into the Atmosphere through Indirect Use
of Fossil Fuels in Agriculture .................................................................................... 42
Emission of Various Gases from Biomass Burning ............................................... 43
Average Emissions of Carbon from Selected Herbicides ..................................... 46
Levels of Emissions of Nitrous Oxide by Type of Fertilizer ................................ 48
Production of Animal and Poultry Excretions/Wastes by Type
of Animal/Poultry...................................................................................................... 50
Carbon Emissions from Animal Excretions/Wastes in Solid Storage................ 51
Carbon Emissions from Animal Excretions/Wastes in Pasture.......................... 51
Use of Heating Fuel by Type of Livestock Farm, 1994.......................................... 52
Estimates of Expenditures and Quantity of Electric Power by Type
of Livestock Farms, Canada and U.S. ...................................................................... 53
Distribution of Source of Electric Power Generation (Percent of Total)
by Province, 1994 ........................................................................................................ 54
Methane Emission Rates from Farm Animals........................................................ 55
Canadian Economic and Emissions Model for Agriculture: Report 1
List of Tables
4.16
4.17
4.18
4.19
5.1
5.2
5.3
5.4
5.5
5.6
5.7
5.8
5.9
5.10
5.11
5.12
6.1
6.2
6.3
6.4
6.5
6.6
6.7
6.8
6.9
6.10
6.11
6.12
6.13
6.14
Methane Emission Rates from Livestock Excretions/Wastes .............................
Nitrous Oxide Emissions from Grazing Animal Excretions/Wastes ................
Nitrous Oxide Emissions from Stored Animal Excretions/Wastes ...................
Nitrous Oxide Emissions from Stored Animal Excretions/Wastes
Applied in the Field ...................................................................................................
Land Use in Canada, 1994.........................................................................................
Area Cropped In Canada by Type of Crops, 1994 ................................................
Distribution of Cropped Area in the Prairies by Tillage Systems, 1994.............
Livestock Inventories on Farms in Canada, by Type, 1994 .................................
Emissions of Greenhouse Gases Not Included in this Study, 1994 ....................
Total Greenhouse Gas Emissions, CO2-equivalent, by Gas, kilo
tonnes per year, 1994 .................................................................................................
Total Greenhouse Gas Emissions, CO2-equivalent, by Gas and GHG
Emission Activity, Crop and Livestock Production, kilo tonnes
per year, 1994 ..............................................................................................................
Total Greenhouse Gas Emissions, CO2-equivalent, by Gas and
Province, kilo tonnes per year, 1994 .......................................................................
Estimated Carbon Dioxide Emissions for Agricultural Production
Activities, and Comparison with Other Study Estimates, 1994 ..........................
Estimated Methane Emissions for Agricultural Production Activities,
and Comparison with Other Study Estimates, 1994 .............................................
Estimated Nitrous Oxide Emissions for Agricultural Production
Activities, and Comparison with Other Study Estimates, 1994 ..........................
Distribution of Greenhouse Gas Emissions* in kilo tonnes per year,
Canada by Province, 1994 .........................................................................................
Change in the Area Under Crops, Prairies Provinces, by Tillage
Systems, 1994 ..............................................................................................................
Area of Crops under No-Till Tillage System under Scenario One, 1994 ..........
Change in the Livestock Inventories for Beef and Hog Enterprises,
Western Canada, Scenario Two, 1994 .....................................................................
Change in Land Use Pattern, Western Canada, Scenario Two, 1994 .................
Total Emissions from Crop and Livestock Production, Canada, by
Gas in CO2-equivalent Level, Scenario One...........................................................
Total Carbon Dioxide Emissions by Agricultural Activities, Canada,
Scenario One ...............................................................................................................
Total Nitrous Oxide Emissions, Absolute and CO2-equivalent,
Canada, Scenario One................................................................................................
Carbon Dioxide Emissions, Canada by Provinces, Scenario One ......................
Nitrous Oxide Emissions, Absolute and CO2-equivalent and Actual,
by Province, Scenario One ........................................................................................
Total GHG Emissions in CO2 Equivalence by Gas, Canada,
Scenario Two ..............................................................................................................
Total Greenhouse Gas Emissions in CO2-equivalent, by Gas
and Emission Activity, Scenario Two .....................................................................
Carbon Dioxide Emissions by Regions, Scenario Two.........................................
Methane Emissions by Regions, Scenario Two .....................................................
Nitrous Oxide Emissions by Regions, Scenario Two............................................
55
57
57
58
62
63
63
64
65
66
67
68
70
71
72
73
76
77
78
79
80
80
81
81
82
83
84
85
86
87
Canadian Economic and Emissions Model for Agriculture: Report 1
List of Tables
A.1
A.2
A.3
A.4
B.1
D.1
D.2
D.3
E.1
E.2
E.3
E.4
E.5
E.6
E.7
E.8
E.9
E.10
Regional Disaggregation for C.E.E.M.A. ............................................................. A-1
Specification of Crop Production Activities in C.E.E.M.A. ................................ A-2
Specification of Livestock Production Activities In C.E.E.M.A. ....................... A-6
List of Acronyms Used in the Greenhouse Gas Emission Sub-Model ............ A-7
Estimated Change in Carbon in Agricultural Soils, by Province ...................... B-1
Levels of Fertilizer Used in the Production, by Crop and Regions.................. D-2
Fuel Use (in litres per acre) for Crops, by Regions ............................................ D-3
Herbicide Cost per Acre, by Crop and Regions (All costs are in dollar
per acre)...................................................................................................................... D-4
Total Emissions of Greenhouse Gases, British Columbia, kilo tonnes
per year, by GHG Activities, 1994.......................................................................... E-1
Total Emissions of Greenhouse Gases, Alberta, kilo tonnes per year,
by GHG Activities, 1994 ......................................................................................... E-2
Total Emissions of Greenhouse Gases, Saskatchewan, kilo tonnes
per year, by GHG Activities, 1994 ........................................................................ E-3
Total Emissions of Greenhouse Gases, Manitoba, kilo tonnes per year,
by GHG Activities, 1994 ........................................................................................ E-4
Total Emissions of Greenhouse Gases, Ontario, kilo tonnes per year,
by GHG Activities, 1994 ........................................................................................ E-5
Total Emissions of Greenhouse Gases, Quebec, kilo tonnes per year,
by GHG Activities, 1994 ........................................................................................ E-6
Total Emissions of Greenhouse Gases, New Brunswick, kilo tonnes
per year, by GHG Activities, 1994 ........................................................................ E-7
Total Emissions of Greenhouse Gases, Prince Edward Island, kilo
tonnes per year, by GHG Activities, 1994 ........................................................... E-8
Total Emissions of Greenhouse Gases, Nova Scotia, kilo tonnes per year,
by GHG Activities, 1994 ........................................................................................ E-9
Total Emissions of Greenhouse Gases, Newfoundland, kilo tonnes
per year, by GHG Activities, 1994 ...................................................................... E-10
Canadian Economic and Emissions Model for Agriculture: Report 1
List of Figures
1.1
Contributions of Agriculture to Global Warming in the 1990’s ..............................4
3.1
Major Sources of Carbon Dioxide Emissions from Agricultural
Production Actitivities................................................................................................24
3.2
Major Sources of Methane Emissions from Agricultural
Production Activities .................................................................................................. 25
3.3
Major Sources of Nitrous Oxide Emissions from Agricultural
Production Activities ...................................................................................................25
3.4
A Schematic Representation of “Carbon Cycle” involving Crop
Production .....................................................................................................................27
3.5
An Overview of the Canadian Economic and Emissions Model
for Agriculture (C.E.E.M.A.).......................................................................................34
4.1
Emissions of Greenhouse Gases from Livestock Excretions/
Wastes and Manures....................................................................................................45
5.1
Regional Distribution of Agriculturally-Induced Emissions
of Greenhouse Gases in Canada, 1994 ......................................................................74
7.1
Sources of Emissions of Greenhouse Gases from Agriculture
and Agri-Food Sector...................................................................................................94
Canadian Economic and Emissions Model for Agriculture: Report 1
Foreword
The Policy Branch of Agriculture and Agri-Food Canada has a
mandate to provide the Government of Canada with timely
information on the impacts that proposed new policies could have on
the agricultural sector, or what the possible outcome would be if
existing policies and programs are altered. Increasing emphasis is
being placed on the interrelationships between environmental
stability and the farm management practices promoted by
agricultural policies. However, to date there has been a lack of
quantitative tools which could be used to address this issue.
This is one of a series of three Technical Reports which document an
integrated agro-ecological economic modelling system that can be
used to simultaneously assess the economic and the greenhouse gas
emission impacts of agricultural policies at regional and national
levels. The model provides a quantitative tool which can contribute
to policy analysis related to Canada's Kyoto commitment to reduce
greenhouse gas emissions.
The model and results presented in this report are based on
information that was available at the time that the analysis was
completed. However, the scientific study of greenhouse gas
emissions is a dynamic process, and estimates of emission
coefficients need refining as scientific research evolves.
Consequently, the estimates of greenhouse gas emissions associated
with Canadian agricultural production presented here are
preliminary, and do not represent the most recent estimates of the
research community (see the "Health of Our Air" report soon to be
released by the Research Branch of Agriculture and Agri-Food
Canada for current estimates of greenhouse gas emissions). As part
of future work, the model described here will evolve and be
consistent with the latest scientific findings.
These preliminary results are an indication of the types of analyses
that may be carried out using the methods applied to this project.
The emphasis is on the development of a quantitative tool for
Canadian Economic and Emissions Model for Agriculture: Report 1
xiii
Foreword
assessing both the economic and the environmental impacts
of mitigative strategies for reducing greenhouse gas
emissions. Refining the coefficients used in the model and
analysing the impacts of mitigative actions will require
additional work.
The initial development of the modelling system was
contracted to the Centre for Studies in Agriculture, Law and
the Environment, University of Saskatchewan, Saskatoon,
with collaboration from Policy Branch, Research Branch and
the Prairie Farm Rehabilitation Administration of Agriculture
and Agri-Food Canada.
Brian Paddock
Director
Policy Analysis Division
Policy Branch
xiv
Canadian Economic and Emissions Model for Agriculture: Report 1
Executive Summary
Under the general umbrella of the Framework Convention on
Climate Change, signed in Rio de Janiero in 1992, a need for
understanding the relationship among various anthropogenic
activities and emissions of greenhouse gases into the atmosphere
was identified by various countries. Such information is needed both
for understanding the process of emissions as well as for devising
ways and means of reducing such emissions in future.
The focus of this study is on agricultural production. It was necessary
to consider the regional make up of the industry and various
production-related activities associated with agricultural production
in developing policy choices. This study was conducted to develop a
framework estimating greenhouse gas emissions from the Canadian
agriculture sector. This framework involves estimation of the
trade-offs (if any) from mitigating global warming through reduction
of emissions of greenhouse gases. Such trade-offs may be in the form
of economic-environmental changes. Reduction in the emission of
greenhouse gases may have an effect on the farmers' economic
status. Thus, it was considered necessary to look into both of these
aspects of the policy decisions. However, since examination of
economic aspects of various policy is common, emphasis in this
study is on the environmental changes, limited to emissions of
greenhouse gases from agriculture.
To accomplish the objectives of the study, an economic resource
allocation cum planning model of Agriculture and Agri-Food
Canada, called the Canadian Regional Agriculture Model (CRAM)
was linked to a greenhouse gas emissions (GHGE) sub-model,
developed specifically for this purpose. The resulting model is called
the Canadian Economic and Emissions Model for Agriculture
(C.E.E.M.A.). The model is disaggregate in nature, both in terms of
farm enterprises and regions. In addition, within the GHGE
sub-model, two modules, one for crops and the other for livestock,
were developed. In each of these modules, twelve agricultural
Canadian Economic and Emissions Model for Agriculture: Report 1
xv
Executive Summary
activities were identified being related to the emissions of
greenhouse gases.
Based on the analysis presented in this report, in 1994,
Canadian
agricultural
production-related
activities
contributed some 62.5 Mt per annum of various greenhouse
gases. Three gases are significant in terms of emissions,
carbon dioxide, methane, and nitrous oxide. The estimated
emissions were converted into "Carbon Dioxide Equivalent"
using their respective global warming potential over a
100-year horizon. In terms of relative contributions, methane
has the highest contribution, when converted into carbon
dioxide equivalent levels. This contribution is 47% of the
total greenhouse gas emissions in 1994, and is followed by
carbon dioxide, and nitrous oxide.
In terms of regional distribution, Western Canadian
agriculture contributes almost two-thirds to the total
emissions, while the remaining one-third emissions are
generated by Eastern Canadian agriculture. In the west, both
Alberta and Saskatchewan are the major contributors,
whereas in the east, most of the emissions are from Ontario
and Quebec. Within agriculture, crop production contributes
slightly under half (48%) of the total emissions of the three
greenhouse gases. The model was also tested in two policy
simulations: effect of increased no-till practice, and expansion
in livestock production in Western Canada.
Contents of this report include details only on the emission
levels. These estimates are based on the best available
scientific research as of the time of conducting research
(Middle of 1997). Some of these numbers are therefore,
preliminary, since the scientific community has less
confidence in the nature of the relationship between
production activities and the factors that determine emissions
of greenhouse gases. As our knowledge base improves, it is
hoped that this methodology would be helpful in revising the
estimates of emissions of greenhouse gases from agricultural
industry.
xvi
Canadian Economic and Emissions Model for Agriculture: Report 1
Acknowledgements
The authors would like to acknowledge the assistance and cooperation received from the
following individuals:
•
Dr. Robert J. MacGregor for his direction and valuable advice over the course of the
project;
•
Ted O'Brian for his valuable suggestion at the start of the project on the study
methodology;
•
Mark Ziegler for many valuable comments on earlier drafts of this report;
•
Jane Reimer, Ahmad Gheidi, Dan Hawkins, Charles Ducasse, and Clarice Springford, for
their help in collection of information, and other clerical activities;
•
Professor Clair Lipscomb, of the English Department, University of Saskatchewan, for
the technical editing of an earlier draft of this report;
•
Tulay Yildirim and Dr. Hartley Furtan for assistance related to contract activities;
•
Members of the Draft Report Review Committee, Mark Ziegler, Saiyed Rizvi, Philippe
Rochette, Ray Desjardins, and Ted O'Brian, for many constructive criticisms and
suggestions for improving the draft report;
•
Bruce Junkins for reviewing the revised draft of the report and for making many valuable
suggestions;
•
Debbie Stefaniuk, of the Department of Agricultural Economics, University of
Saskatchewan, for doing a meticulous job of formatting the final draft of the report; and,
•
Agriculture and Agri-Food Canada, Economic Policy and Analysis Directorate, Policy
Analysis Division, for the financial assistance, without which this study would not have
been completed.
Canadian Economic and Emissions Model for Agriculture: Report 1
xvii
Chapter 1: Introduction
1.1
Background
Ever since the coining of the phrase "sustainable development" by the World Commission on
Environment and Development1, there has been a change in the manner economic
development programs are designed and implemented. As a result, efforts of many
government and non-governmental organizations the world over have been guided,
implicitly or explicitly, by concerns for the sustainability of economic activity, social
structures, and ecosystems. One of the major concerns/threats to sustainability is the effect of
economic and other anthropogenic2 activities on the ecosystem, which, in turn, affects the
long term potential for many of the resource-based economic activities.
The effect of human activities on changing the atmospheric concentration and distribution of
greenhouse gases (GHGs) and aerosols is regarded as one of the most significant changes
affecting economic activities. It has been predicted that these changes, if not checked, will
have an adverse effect on the food supplies in various parts of the world. The
Intergovernmental Panel on Climate Change (IPCC) both in the first assessment (see Watson
et al. 1990, and Houghton, Jenkins and Ephraums, 1990), as well as in the most recent (1995)
assessment concluded the following.
Agricultural production can be maintained, relative to baseline production in
the face of climate changes likely to occur over the next century (i.e., in the
range of 1.0o to 4.5o C), although wide variation would exist between regions
(Reilly et al., 1996, p. 429).
Studies have identified both beneficial as well as adverse effects of climate changes. The
beneficial effects are elevated concentration of carbon dioxide (CO2) that would increase the
yield for most crops (except maize, millet, and sorghum). The adverse effects are loss of soil
organic matter (SOM), leaching of soil nutrients, salinization and erosion, and increased
1.
For more discussion on the concept of sustainable development, see WCED (1987).
2.
According to the Webster dictionary, anthropogenic activities are those that are related to the impact of man
on nature (ecosystem).
Canadian Economic and Emissions Model for Agriculture: Report 1
1
Chapter 1
infestation of weeds, insects, and diseases. In addition, the probability of extreme events
(such as droughts and floods) is also expected to increase, which would further create
instability in regional economies3.
Consequently the recent concerns of the world community are focused on the rapidly rising
atmospheric concentration of various GHGs. The major ones that have been identified,
particularly in the context of agricultural production, are: Carbon dioxide (CO2), Methane
(CH4), and Nitrous Oxide (N2O)4. The concentration of these three GHGs has been increasing
rapidly, as shown in Table 1.1.
Table 1.1: An Overview of Greenhouse Gases Emissions Affected by Anthropogenic
Activities
Particulars
Unit of
measurement
CO2
CH4
N2O
Pre-industrial Concentration
ppmv
~280
~0.700
~0.275
Concentration in 1990
ppmv
353
1.72
0.31
Concentration in 1994
ppmv
358
1.72
0.312
% per year
0.4
0.6
0.25
Over 20 years time horizon
1
11
280
Over 100 years time horizon
1
21
310
50-200
12
120
Rate of Change (1984 to 1994)
CO2 = 1
Global Warming Potential
Atmospheric life
Years
ppmv = parts per million by volume
Source: Houghton et al. (1996)
According to the IPCC, these changes can produce radiative forcing (i.e., global warming)
either by changing the reflection or absorption of solar radiation, or by the emission and
absorption of terrestrial radiation. The United Nations Framework Convention on Climate
Change (FCCC) referred to this phenomenon as “climate change” brought about by human
activities. Although sources of GHGs are both natural and human-induced, according to
Stern, Young, and Druckman (1992), population growth, economic growth, and
technological change5 are the major driving forces for the increasing human-environmental
interactions.
3.
This is not to suggest that agriculture is the only sector affected by climate changes. Other sectors such as
forests, energy production, fisheries, and human health, are also affected, some more severely than others.
4.
In the context of other economic activities, a number of trace gases are included in this category. These
include: water vapor, carbon monoxide (CO), and nitric oxide (NO), halocarbons and other halogenated
compounds, and ozone. Halocarbons are carbon compounds that contain fluorine, chlorine, bromine, or
iodine. According to Houghton et al. (1996, p. 19), human activities is the sole source of halocarbons.
5.
These three forces interact with each other, as well as with existing political-economic institutions in a given
country. Interactions among them are contingent on spatial location as well as on time period.
2
Canadian Economic and Emissions Model for Agriculture: Report 1
Introduction
GHGs, which have been identified since pre-industrial times, tend to warm the earth's
surface and to produce other changes (Houghton et al., 1996, p.3). These changes in the
climate are a major global concern. Among these effects, four are particularly noteworthy:
•
change in the spatial distribution of average temperature and precipitation;
•
change in the inter-annual variability in temperature and precipitation, increasing
the probability of occurrence of extreme events (droughts and floods);
•
change in the seasonal variation in temperature and precipitation; and,
•
rise in the sea level.
Reviewing past evidence and trends, the FCCC indicated a concern that such changes may
adversely affect natural ecosystems and human kind (Mintzer and Leonard 1994, p. 335).
1.2
Importance of Agricultural Emissions of Greenhouse Gases
Although the main source of GHGs is the world's fossil fuel based energy system, a very
significant source originates from biotic, mostly land-based, sources (Watson et al. 1992), of
which agriculture is an important contributor6.
1.2.1 Global Emissions
For the world as a whole, Reilly and Bucklin (1989, as quoted by Swaminathan 1991)
estimated that agriculture sector contributed 25.6% of the total world GHG emissions. As
shown in Figure 1.17, a majority of these emissions are from ruminants, rice paddies, and
biomass burning (particularly the burning of fuel-wood). Land use conversion, from forests
to arable lands, is the next higher source of agriculture's contribution. This is particularly true
in tropical countries, where deforestation is rampant on account of pressures on currently
available arable land. In addition, tilling of land and ruminant livestock production are also
responsible for a part of these emissions.
Duxbury, Harper and Mosier (1993) reported a distribution of the contributions of
agriculture to total global GHG emissions. Nitrous oxide is highest (at 92%), followed by
methane (at 65%), and carbon dioxide is only a quarter of the total emissions as shown in
Table 1.2.
6.
However, the magnitude of this contribution varies from region to region. In the complex relationship of
these gases to global warming, one should also consider the interaction of these gases. For example, carbon
monoxide is important because of its influence on atmospheric concentration of methane.
7.
One should note the confusion in the figure because of inclusion of biomass burning counted twice. It is the
authors' interpretation that one of the biomass burning is associated with fuelwood burning, while the other
with burning of crop biomass.
Canadian Economic and Emissions Model for Agriculture: Report 1
3
Chapter 1
Figure 1.1: Contributions of Agriculture to Global Warming in the 1990’s
Agriculture’s Total Contribution 25.6%
Fertilizers, cultivated natural soils, biomass burning
2.6%
13%
Ruminants, rice paddies, biomass burning
10%
Land use conversion (deforestation)
Source: Swaminathan (1991, p. 275)
1.2.2 Canadian Emissions
For Canada, estimates of levels of GHG emissions from agricultural activities are in the
process of development, although a number of significant strides have been made. As shown
in Table 1.2, based on estimates from another study8, Liu (1995) reported agriculture's
contributions to total emissions of carbon dioxide in Canada at 4% of the total. For the other
two GHGs, agriculture's contributions are relatively higher, estimated to be almost a quarter
of the total. Relative contributions of agriculture in Canada to the total emissions are
somewhat lower than those on the global scale because: the carbon in Canada's agricultural
soils has almost reached an equilibrium9; the area of agricultural land has stabilized; and, rice
production, which is a high contributor to methane emissions, is not important in Canada
(Liu 1995).
Desjardins (1997) produced a more detailed estimation of total emissions of the three GHGs
from agricultural and related activities, as shown in Table 1.3. Agricultural activities in
Canada contribute about 17 mega tonnes (Mt)10 of carbon dioxide annually. Emissions of
methane and nitrous oxide in 1991 were estimated to be relatively smaller, at 973 and 62 kt
per year, respectively. The latter includes 39 kilo tonnes (kt)11 of emissions directly by
agriculture and another 23 kt through other sources of emissions of nitrous oxide. For both
methane and nitrous oxide, although their absolute level of emissions is low, when
converted to "CO2 Equivalence", agriculture emits 20.4 Mt as methane, and 12.2 Mt annually
as nitrous oxide.12
8.
Liu quotes a study by Jaques (1992) as the source of these estimates.
9.
Agricultural soils will be a net carbon sink by 2008 which has positive implications with respect to Canada's
commitment to reduce greenhouse gas emissions to 6% below 1990 levels by 2008-2012 under the Kyoto
Protocol.
10. Mt refers to one million tonne (metric ton) or 1012 grams.
11. A kt refers to one thousand tonnes or 109 grams.
12. These emission levels are estimated using a carbon dioxide equivalent factor of 21 for methane, and 310 for
nitrous oxide
4
Canadian Economic and Emissions Model for Agriculture: Report 1
Introduction
Table 1.2: Contribution of Agriculture to Greenhouse Gas Emissions, by Type of Gas,
Global and Canada
Unit
CO2
CH4
N2O
Total Anthropogenic Emissions
Mt yr -1
24,933
340
3.77
Emissions from the Agricultural Sector
Mt yr -1
6,483
221
3.47
% of total
26
65
92
Total Anthropogenic Emissions
Mt yr -1
467
3.7
0.11
Emissions from the Agricultural Sector
Mt yr -1
20.8
1
0.03
4
26
29
Particulars
GLOBAL
Agriculture's Share
CANADA
Agriculture's Share
% of total
Source: Global: Duxbury, Harper and Mosier (1993), as reported by Liu (1995).
Canada: Jaques (1992) as reported by Liu (1995).
Table 1.3: Estimates of Greenhouse Gases Emissions from Agricultural Activities,
Canada, 1991
CO2
kt yr -1
CH4
kt yr -1*
N2O
kt yr -1
6,300
12
32.34
10,700
-
-
Animal Production
-
961
7.1
Indirect Emissions
-
-
16.79
Other Sources
-
-
5.69
17,000
973
61.92
Source
Direct Soil Emissions
Stationary and Transport Combustion
TOTAL
*kt = Kilo tonne, equal to 103 (thousand) tonnes
Source: Desjardins (1997).
1.3
Need for the Study
After two years of intensive negotiations and discussions, in June 1992, some 153 countries
around the world, including Canada, signed the United Nations FCCC at Rio de Janeiro. The
purpose of this Convention was to set up strategies to stabilize the concentration of all GHGs
in various parts of the globe in order to reduce one of the major threats to sustainable
development.
The Convention required all parties to develop national inventories of anthropogenic
emissions of GHGs (Khanna and Prakash 1993, p. 252). In addition, signatories from the
developed countries also committed to “adopt national policies and take corresponding
measures on the mitigation of climate change by limiting anthropogenic emissions of
greenhouse gases and protecting and enhancing their greenhouse gas sinks and reservoirs”
Canadian Economic and Emissions Model for Agriculture: Report 1
5
Chapter 1
(Mintzer and Leonard 1994, pp. 342-343). Furthermore, these measures included, among
others, formulation, implementation, publication, and (updating) national strategies for
abatement of and adaptation to climate change.
Under the FCCC, each of the signatories was expected to identify and review periodically its
own policies and practices which contribute to GHGs. However, this requires two types of
information. One is more precise estimates of total GHGs in various countries (including
Canada) for the base period; and, the other is knowledge of change in the emission levels
through the adoption of a selected set of policies.
Integration of environmental considerations in the decision-making process for agricultural
production activities is warranted on another ground. In order to select appropriate
farm/agricultural policies, policy makers require information, not only on the assessment of
economic effects of the selected program(s), but also on their environmental effects. This is
consistent with the consideration of sustainability. As Faeth (1995) indicated “Credible
information of the ... impacts of movements toward sustainability is sorely needed.” Policies
need priorities not only on the basis of their short-term economic returns, but also in terms of
the long-term damage to the environment, and through that, on the long-run returns from
agricultural production. In fact, one could visualize a trade-off between the economic and
environmental objectives, where decrease in the environmental damage may be associated
with some economic sacrifices.
In order to provide a balanced perspective, policy analysis, in the context of mitigating the
greenhouse effect, must consider the costs and benefits of such measures. For farmers,
adoption of some mitigative measures may result in loss of economic benefits. This suggests
a need for an integrated modelling of agricultural activities, where both economic and
environmental (for example, in this study, GHG emissions) indicators are estimated
simultaneously. In addition, economic policies, if implemented, would also change the
nature and levels of economic activities. This again suggests the need for an integrated model
for Canadian agriculture, where the economic activities are integrated with environmental
changes such as GHG emissions.
At the present time, an economic planning model for Canadian agriculture, called CRAM —
does exist13. This model can be used to evaluate alternative economic policies using economic
criteria. However, in preparation for developing mitigating policies for GHG emissions,
there is a need for integrating the CRAM with a model that can estimate the emissions
induced by various agricultural activities.
1.4
Objectives of the Study
The major objective of this study is to develop a methodology to estimate the emission levels
of the three major greenhouse gases (carbon dioxide — CO2, methane — CH4, and nitrous
oxide — N2O) that various agricultural activities produce. This is accomplished by
constructing the C.E.E.M.A. This model has two sub-models, one economic planning submodel, and the other, GHG emissions sub-model. The methodology for the GHG sub-model
is formalized as an accounting block, which is then linked to CRAM. Using this model,
impacts of changing agricultural policies can be estimated, in terms of both economic
objective(s) and emission levels for major GHGs.
13. For more details on CRAM, see Horner et al. (1992).
6
Canadian Economic and Emissions Model for Agriculture: Report 1
Introduction
A secondary objective of this study is to apply the integrated model for evaluation of two
policies: Increased livestock production on the Prairie provinces, and adoption of
conservation tillage systems on farms in Western Canada. These scenarios were chosen in
light of their current interests and in terms of the ease of their implementation.
1.5
Scope of the Study
In this study, as mentioned above, three major GHGs are studied: carbon dioxide, methane,
and nitrous oxide. Although other gases may be relevant, the available evidence does not
suggest that they play an important role in the process of climate change, and for that reason,
are not included in this study. The sub-model for the estimation of the GHGs takes into
account the direct linkages between agricultural activities and emission levels of GHGs.
Even here, the scope of estimation was limited to only crop production and livestock
production activities. Within livestock production, the scope of estimation was further
limited to major livestock only, beef and dairy cattle, hogs, and poultry. Any activity not
directly related to the production of crops or livestock was not included in this study14.
Unlike the IPCC evaluation of GHG emission levels, no natural-source emission levels are
estimated in this study.
In addition to model limitations of scope of the study, another source of uncertainty in the
results of the model is the preliminary nature of the information. The scientific community
has low to moderate degree of confidence in the estimation of some of the GHG emissions.
Since this study adopted their state-of-the-art, the results contained in this study should be
construed as preliminary. As better estimates of emission of GHGs become available, these
results could be upgraded.
1.6
Organization of the Report
The rest of the report is divided into six chapters. In Chapter 2, a conceptual basis for
developing a sub-model for emission of GHGs is outlined. Included here are the conceptual
linkages between agricultural production activities and nature of emissions of GHGs. An
overview of the GHGE sub-model, and the considerations involved in its development, are
provided in Chapter 3. A description of the methodology that was adopted in the estimation
of the various emission coefficients for crop and livestock production activities follows in
Chapter 4. Results of the base line scenario, agricultural production in 1994 as estimated in
CRAM sub-model, and the induced emissions, are shown in Chapter 5. Results for the two
alternative scenarios are presented in Chapter 6. A summary of the report and areas for
further research are discussed in Chapter 7.
14. Several other activities were identified as being relevant in the context of agriculturally- induced emissions of
greenhouse gases. More details on the activities not included in the estimation are provided in Chapter 2,
Section 2.2.
Canadian Economic and Emissions Model for Agriculture: Report 1
7
Chapter 2: Linkages Between
Agricultural Production Activities and
Emission of Greenhouse Gases
The major objective of this chapter is to describe the role played by various agricultural
production activities in determining the level of emission of three major GHGs. In addition,
agriculturally-induced (physical or management) factors that affect these emission levels are
also reviewed. This helps the development of the analytical framework for estimating the
emission of GHGs from Canadian agricultural activities.
2.1
Sources of Major Greenhouse Gases Emissions at the Global Scale
The three GHGs selected for this study, carbon dioxide, methane, and nitrous oxide, have
different cycles and levels of fluxes. Each of these is described below.
2.1.1 Carbon dioxide
Carbon dioxide (CO2) is continuously exchanged among atmosphere, oceans, and all living
organisms (biota). Land and the associated biota are net sinks for carbon, which can be
released through various anthropogenic activities, including agricultural activities. Major
sources of emission of CO2 over the globe are shown in Table 2.1, with the estimated level of
flux and the role played by agriculture.
Canadian Economic and Emissions Model for Agriculture: Report 1
9
Chapter 2
Table 2.1: Major Sources of Global Emissions of Carbon Dioxide, Annual Flux,
Average 1980 to 1999
Average Annual Flux*
in Gt of C yr -1
Source of Emissions
Role of Agricultural
Production Activities
Fossil fuel consumption and
cement production
5.0 - 6.0
Major, through use of fossil
fuels directly or indirectly
Changes in tropical land use
0.6 - 2.6
Minor in terms of direct
agricultural production
Total
6.0 - 8.2
--
*A Gt (giga tonne) is equivalent to one bullion (109) tonnes.
Source: Schimel et al. (1995), p. 5.
According to these estimates, burning of fossil fuels and cement production are the major
source of CO2 emissions. Agricultural production activities contribute to these emissions
through combustion of fossil fuels, coal, oil, and natural gas. Change in land use from natural
vegetation (woodlands and forests) to arable lands for agricultural production also released
stored carbon (C) to the atmosphere, but since much of this activity in Canada took place
during the early part of the 20th century15, it is outside the scope of current levels of direct
emissions from agricultural production.
Atmospheric CO2 provides a link among the processes of plants, animals, and human beings.
The carbon cycle involves photosynthesis which fixes atmospheric CO2 in plants, the increase
of organic carbon in the soil by plant residues and the spreading of manure, and the increase
in atmospheric CO2 by respiration. Photosynthesis is very important for the reduction of CO2
emissions from agriculture. Through increasing the annual amounts of the photosynthetic
process, more atmospheric CO2 is fixed in plant tissue and potentially in the soil organic
matter.
The amount of soil microbial respiration, which reflects the amount of soil organic carbon
being converted to atmospheric CO2, is also an important element of carbon cycling.
Measuring the soil microbial respiration provides information on the factors governing the
carbon flux between the soil and the atmosphere. The balance between soil microbial
respiration and photosynthesis determines whether the ecosystem is a net source or sink of
atmospheric CO2 (Ellert, Janzen and McGinn 1994). This balance is affected by several
factors, especially the nature of crops grown and their subsequent use (exports versus
livestock feed). If a crop material is used further as a livestock feed, this balance will be
further modified by contribution of livestock production to the emission of the GHGs.
The balance between soil microbial respiration and photosynthesis is crucial when
attempting to control the increasing global emissions (Daynard and Strankman 1994). In
addition, Anderson (1995) suggested that other factors being equal, organic carbon generally
increases with clay content of the soil, although the role played by clay may be reduced in
colder temperatures.
15. Such deforestation is still taking place in tropical countries of Central and South America.
10
Canadian Economic and Emissions Model for Agriculture: Report 1
Linkages Between Agricultural Production Activities and Emission of Greenhouse Gases
2.1.2 Methane
After water vapor and carbon dioxide, methane is the most abundant greenhouse gas in the
troposphere, the lowest level of the atmosphere (Prather et al. 1995, p. 85). In addition,
methane is eleven times as potent a greenhouse gas as carbon dioxide, and its concentration
in the atmosphere is increasing faster (about 1-2% per annum) than any of the other GHGs.
Since the industrial revolution, methane has increased by 115%, which is much higher than
the increases of 26% and 7% seen in carbon dioxide and nitrous oxide, respectively (Steed
and Hashimoto 1994). The concern over methane is its infrared radiation absorption capacity,
which is 58 times16 larger than that of CO2 on a mass basis, and methane generates carbon
dioxide, ozone (O3) and water vapor in the troposphere and stratosphere above the
troposphere (Lauren, Pettygrove and Duxbury 1994).
The annual levels of methane (CH4) emission are smaller than those for CO2. Global estimates
range from 410 to 660 tera17 grams (Tg) of CH4 (Table 2.2). Methane emissions are produced
from both natural and human-related (anthropogenic) sources. The natural sources include
intestinal fermentations in ruminants (cattle, buffalo, sheep, goats, and deer) and certain
insects, animal excretions/wastes, and the decomposition of organic matter under anaerobic
conditions from water-logged (saturated) soils. Combustion of coal, natural gas leakage from
pipelines, burning of plant matter in the tropics, and municipal landfills are some of the
anthropogenic sources of methane (Lessard et al. 1994), which account for 65% of global
methane emissions.
Table 2.2: Major Sources of Global Emissions of Methane, Annual Levels
Average Annual Flux
in Tg of CH4 yr -1
Role of Agricultural
Production Activities
Natural Sources of Emissions
110 - 220
None
Production of Fossil Fuels
70 - 120
None
Enteric Fermentation
65 - 100
Major
Rice Paddies
20 - 100
None in Canadian context
Biomass Burning
20 - 80
Minor
Landfills
20 - 70
None
Animal Excretions / wastes
20 - 30
Major
Domestic Sewage
15 - 80
None
410 - 660
--
Source of Emissions
Total
Source: Prather et al. (1995), p. 86.
16. One should note differences, among studies, related to radiation absorption capacity of methane.
17. A tera gram refers to a billion grams or 1012 grams, equivalent to one million tonnes.
Canadian Economic and Emissions Model for Agriculture: Report 1
11
Chapter 2
Anaerobic fermentation is the primary source of methane from contemporary biological
sources, both agricultural and natural18. Methane is generated through anaerobic
fermentation by microorganisms in lower intestines of animals and in various habitats such
as large heaps of organic matter which could be buried and peat bogs. Basically, methane
generation occurs wherever microorganisms carry out decomposition with the absence of
free oxygen, as well as sulphates, nitrates, and ferric iron (Topp and Patty 1997). In this sense,
it is an anaerobic equivalent to carbon dioxide in the carbon cycle. Among the agricultural
sources of methane, burning of biomass, and raising of cattle and other ruminants are the
most significant sources19. All animals discharge a part of their feed energy in the form of
methane as a consequence of fermentation of carbohydrates during the process of digestion.
On the other side of the methane cycle, major sinks include the chemical reaction with
hydroxyl radical in the troposphere, and possibly soil methanotrophic bacteria (Lessard et al.
1994).
2.1.3 Nitrous Oxide
Nitrous oxide (N2O) is an even more powerful GHG than methane or carbon dioxide, being
270 to 31020 times as effective per molecule as CO2. However, its emissions into the
atmosphere are much smaller than those of the other two GHGs. Nitrous oxide is a
radiatively active trace gas produced from various biological sources in both soil and water.
In the 1980s, N2O contributed approximately 6% to the changes of radiative forcing (i.e.,
global warming), as compared to 50% for CO2 and 18% for CH4. It is increasing at a rate of 0.2
to 0.3% per year (Curtin et al. 1994; Li, Narayanan and Harriss, Undated). Though N2O is
chemically inert in the troposphere, it absorbs radiation in the infrared band, thus accounting
for 5-10% of the total greenhouse effect. Only a small amount of the N2O released into the
atmosphere from the earth is returned to the surface. Photochemical decomposition of N2O
to O2 and N2 in the stratosphere is the major atmospheric loss process (Curtin et al. 1994).
Most of the N2O in the atmosphere comes from terrestrial soils and is mainly formed by two
processes: de-nitrification and nitrification.
Total emissions of N2O are estimated to be between 10-17 tera grams (Tg) of nitrogen (N) per
year (Table 2.3), from natural and anthropogenic sources. Among the natural sources, oceans
and soils in tropical forests are the top contributors (Watson et al. 1990; and Bolin et al. 1986).
All of the large anthropogenic sources of N2O, fertilizer use, biomass burning, and grazing of
cattle on pastures and in feedlots are the largest contributors21, are associated with
agricultural activities.
18. Natural sources include all kinds of wetlands, especially peat bogs in northern latitudes. Another source of
methane, particularly under global warming, is methane hydrate, which is trapped in sediments under
permafrost and on continental margins.
19. In addition, rice cultivation in paddies is also a major contributor of methane; however, it is not very
significant in the context of Canadian agriculture.
20. As noted in Table 1.1, the effectiveness of nitrous oxide depends on the length of time considered. For a 20year time horizon, this level is estimated at 280, while the latter (310) is for a 100-year time horizon.
21. There is some doubt about which one of these sources contributes more. The fossil fuels can contribute
between 0.1 to 0.3 Tg N per year, whereas the fertilizers could contribute between 0.01 to 2.2 Tg N per
annum. However, Wuebbles and Edmonds (1988) estimated fossil fuel combustion at 4 Tg N and fertilizer
use at 0.8 Tg N per annum.
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Canadian Economic and Emissions Model for Agriculture: Report 1
Linkages Between Agricultural Production Activities and Emission of Greenhouse Gases
Table 2.3: Major Sources of Global Emissions of Nitrous Oxide, Annual Levels
Source of Emissions
Natural Sources of Emissions
Average Annual Flux
in Tg of N yr -1
Role of Agricultural
Production Activities
6 -12
None
Cultivated Soils
1.8 - 5.3
Major
Biomass Burning
0.2 - 1.0
Large
Industrial Sources
0.7 - 1.8
None
Cattle and Feedlots
0.2 - 0.5
Major
10.0 - 17.0
--
Total
Source: Prather et al. (1995), p. 90.
2.2
Effects of Environmental and Management Factors
Agricultural activities in a temperate climate, such as in Canada's, produce GHGs through
various processes. Seven broad categories of linkages between agricultural processes and
GHG emissions can be hypothesized. These include:
1. Deforestation and clearing of lands for agricultural activities;
2. Tilling of land for crop production purposes, and other related operations;
3. Raising of livestock on farms;
4. Marketing and transportation of agricultural products;
5. Procurement of inputs needed for agricultural production, crop or livestock;
6. Other farm operations, not accounted for above; and,
7. Second-round effect on emissions through production and distribution of agricultural
inputs.
The interrelationship among these activities and GHG emissions is shown in Table 2.4.
Canadian Economic and Emissions Model for Agriculture: Report 1
13
Chapter 2
Table 2.4: Linkages between Emissions of Greenhouse Gases and Activities Related
to Agriculture
Description
1
Change in Land Use
2
Crop Production
3
Animal Production
4
Effect of CO2
Effect on CH4
Effect on N2O
Significant and Positive
Negative
Minor
Negative (sink) through
photosynthesis and soil but
Positive from farm
operations, depending on the
tillage regime and farming
system used
Uncertain
Minor
Uncertain
Positive and
Significant
Minor
Marketing of Output
Positive
--
Minor
5
Procurement of Inputs
Positive
--
Minor
6
Other Farm Operations
Positive from use of farm
inputs, but Negative from
shelterbelts
--
Minor
7
Second Round Emissions
Significant and positive
Positive
Minor
Note: Shaded area are designated as those beyond the scope of the present study.
Change in land use has been accepted as a major source of CO2 flux from agriculture. Angers
(1997) reported a decrease of 15 to 30% in soil carbon in forest soils when converted for
agricultural uses. However, in Canada, much of the deforestation (if any) and clearing of
lands for agricultural activities took place around the early 1900s. Although a relatively
smaller level of conversion of non-agricultural lands into cropped lands still takes place, the
amount each year is marginally small, and thus, its inclusion was not considered significant.
Furthermore, since the purpose of this study is to estimate current levels of emissions, these
emissions were excluded.
Tillage of land for crop production and related operations, as well as raising livestock can
contribute significantly to the GHG emission levels. More details on these activities are
provided in the next two sections (Sections 2.3 and 2.4).
In addition to crop production, other agricultural activities not directly related to either crop
or livestock production may also generate GHG emissions. These activities include:
transportation of crops and livestock from farm to the assembly points (such as grain
elevators for crops, and to stockyards and local abattoirs for livestock); purchase of farm
inputs by farmers, particularly fertilizers, and chemicals; maintenance and repairs of farm
machinery, and other crop or livestock related uses of energy inputs. However, these
emissions are not estimated in this study.
Other farm operations, such as use of energy inputs for farm yards, contribute to the
emissions of GHGs. In addition, many farms have incorporated tree shelterbelts as a measure
against wind erosion. Although these trees act as a sink for CO2 (Kort and Turnock 1997),
they are also not included in this study.
14
Canadian Economic and Emissions Model for Agriculture: Report 1
Linkages Between Agricultural Production Activities and Emission of Greenhouse Gases
In addition to direct emissions through various agricultural practices, many of the
agricultural inputs have embodied energy, and their production and marketing require the
use of raw materials which themselves generate greenhouse gas emissions. For example,
energy used in the production, storing and transportation of fertilizers has been reported at
60,700 kJ22 per kg of nitrogen, 12,500 kJ per kg of phosphate, and 6,700 kJ per kg of potash (as
reported by Manaloor and Yildirim 1996, p. 11). The major sources of these energy inputs are
electricity, liquid fossil fuels, and natural gas. Furthermore, depending upon the region,
electrical power generation requires the use of coal and natural gas23. Use of these types of
fuels yields emissions of GHGs, notably CO2. These emissions are called Second-round
emissions24. Since these emissions are more difficult to estimate25, they are also excluded
from this study.
2.3
Factors Affecting Emission Levels from Agricultural Activities
Within the agriculturally-induced emissions of GHGs, crop and livestock production are the
most significant players. GHG emissions from these production activities are affected by a
set of factors, some of which are anthropogenic in nature. The management practices of
farmers are included in this category. An understanding of these factors is crucial for
estimating the emission coefficient (EC) for various types of agricultural activities.
Since the knowledge of fluxes and biochemical processes causing emissions is essential to
reduce related uncertainties, and to devise means to reduce such emission levels, Agriculture
and Agri-Food Canada (AAFC) undertook a major research initiative entitled "Greenhouse
Gas Research in Agriculture"26. The following discussion is primarily, although not
exclusively, based on the results of this research initiative. In selecting other relevant studies,
emphasis was first placed on those undertaken for Canada. The next preference was given to
studies for the temperate zone of North America. These were supplemented, wherever
necessary, by other studies as a source of information for estimation of ECs used in this
study.
2.3.1 Factors Affecting Emissions from Crop Production
Various management and environmental factors can be identified for the emissions of GHGs
from crop production in Canada. These are described here in the context of each of the three
major GHGs. This summary is based on a review of various studies.
22. A "kJ" stands for kilo joule, which represents 103 joules, where the "joule" is a measure of energy required.
23. In addition to coal and natural gas, electrical power is generated using water and nuclear fusion. These
sources of power do not contribute to emissions of greenhouse gases.
24. These emissions are more distant in nature. Agricultural operations require the use of various inputs, which
on account of their specific production function, require inputs which themselves create emissions of
greenhouse gases. These emissions are therefore, called Second-round emissions.
25. An example of the complexity in these estimations can be seen by the need for an input-output model for
each major type of energy input that is required to produce output of various agricultural inputs.
Development of such models, although has been attempted, requires resources that were not available for
this study.
26. The research was carried out at three levels: process, ecosystem, and integration. Several research projects
were initiated. A summary of selected projects can be found in Agriculture and Agri-Food Canada (1997).
Canadian Economic and Emissions Model for Agriculture: Report 1
15
Chapter 2
2.3.1.1 Carbon Dioxide
A number of factors may affect the exchange of atmospheric CO2 from crop production
activities. Although a list of plausible factors is presented in Table 2.5, major factors affecting
it would include those which lead to gains or losses of carbon stored in SOM. Those practices
adding to the SOM pool include: crop biomass production, rotations followed (particularly
those that exclude summerfallowing) and crop residues left in the field. Those practices
responsible for depletion of SOM include: frequent soil disturbance by tillage, inclusion of
summerfallow in soil rotation, and removal and/or burning of crop residues.
Table 2.5: Factors Affecting Carbon Dioxide Emissions from Crop Production
Practices
Management Practices
Environmental Factors
Tillage practices
Temperature
Rotation followed
Precipitation
Application of manure
Soil moisture content
Use of chemicals and type of herbicide
Organic carbon content
Timing of application of chemicals
Oxygen availability
Use of other chemicals
Porosity
Crop type
pH
Irrigation
Micro-organisms
Residual organic matter from crops
and other sources
The role played by tillage has been a subject of intensive research in Canada and in the U. S.
Results vary from situation to situation, and also on the length of time — short-run or longrun. For short-run changes, a study by Rochette and Desjardins (1997) suggested that SOM
levels in Eastern Canada are not different in no-till soils than in soils tilled with a
mouldboard plough. Similar conclusions are reached by Campbell et al. (1997b), Carter,
Gregorich and Bolinder (1997), and by Rochette, Fortin and Desjardins (1997) for no-till and
conventional tillage operations. In addition, for Western Canada, Campbell et al. (1997b)
reported that the carbon sequestration in soils is found to be much more dependent on
cropping frequency than on method of tillage. Carbon sequestration will occur in systems
where crop residue additions exceed soil carbon losses and the soil is sufficiently protected
by residue cover to prevent losses by wind and water erosion. Examples are systems with
zero or minimum tillage, continuous cropping (those in which summerfallow has been
eliminated), and adequate replacement of nutrients removed from the soil by the crop. Many
researchers have measured increases in the organic matter content of surface soil after 20 to
30 years of low-disturbance, continuous cropping systems that replaced conventional tillage
and summerfallow-based crop production (Boehm and Anderson 1997; Beare, Hendrix and
Coleman 1994; Campbell and Zentner 1993; Janzen 1987).
Besides tillage, other factors also affect SOM. The rate of soil microbial respiration is one
(McGinn and Akinremi 1997), and is dependent on soil temperature (Rochette and
Desjardins 1997), and soil moisture. Straw removal reduces CO2 flux, whereas retention of
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straw increases it (Campbell et al. 1997a; Curtin et al. 1997). The type of straw added to the
field (fresh straw collected shortly after harvest, and standing stubble straw that had
weathered in the field for a year) did not have any significantly different effects on CO2
emissions.
Evidence on the relationship between manure and CO2 flux is relatively poor. Addition of
manure is reported to increase soil carbon (Angers 1997; Rochette et al. 1997a), and through
that process, affects the level of CO2 flux.
2.3.1.2 Methane
Methane emissions related to agricultural operations are from two major sources: ruminant
animals on farms, and livestock excretions and their subsequent use for crop production. Of
these, only the second one is relevant to crop production. Factors that may affect this
methane emission are listed in Table 2.6.
Table 2.6: Factors Affecting Methane Emissions from Crop Production Practices
Management Practices
Environmental Factors
Tillage practices
Temperature
Rotation followed
Precipitation
Application of manure
Soil moisture content
Types of crops receiving manure
Organic carbon content
Timing of application of manure
Oxygen availability
Irrigation
Porosity
Residual organic matter from
crops and other sources
pH
Micro-organisms
2.3.1.3 Nitrous Oxide
Major sources of N2O emissions are from the use of fertilizer and manure to supplement crop
nutrient requirements. Factors affecting such emissions are listed in Table 2.7.
The important factors that affect emissions of N2O from the soil are temperature, pH, and O2
availability. Research into the effect of weather and precipitation suggests that freeze and
thaw cycles have a significant effect on the distribution of emissions within a year (Prevost
and van Bochove 1997; Jones and van Bochove 1997; Brown et al. 1997). A study by Pattey et
al. (1997b) reported that 61% of N2O emissions from the application of urea occurs during the
period of snow melt, when soils are saturated and the level of oxygen in the soils is limited.
Van Bochove et al. (1997) reported that freeze/thaw cycles increase de-nitrification.
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Chapter 2
Table 2.7: Factors Affecting Nitrous Oxide Emissions from Crop Production Practices
Management Practices
Environmental Factors
Fertilizer type
Temperature
Application rate
Precipitation
Application technique
Soil moisture content
Timing of application
Soil Texture
Tillage practices
Soil nitrogen content
Use of other chemicals
Organic carbon content
Crop type
Oxygen availability
Irrigation
Porosity
Residual nitrogen and carbon
from crops and fertilizer
pH
Freeze and thaw cycle
Annual variation
Micro-organisms
Source: Eichner (1990); Gleig and MacDonald (1995).
Farming practices also affect N2O emissions from the soils (Rochette et al. 1997b). Among
these, application of manure is perhaps the most important. The type of manure and rate of
application, according to Pattey et al. (1997b), contribute to emission levels. Fertilization is
also an important contributor to N2O emissions. The impact of type of fertilizers is also
reported to vary significantly from one type to another (Ouyang, Fan, and McKenzie 1997;
and Webb, Wagner-Riddle and Thurtell 1997). Wagner-Riddle (1997) also reported the effect
of the incorporation of alfalfa in crop rotations on N2O emissions. Tillage affects these
emission levels, in that reducing tillage reduces emissions (Lapierre and Simard 1997), and
that 80% of the emissions occurred following fertilization and tillage operations.
2.3.2 Factors Affecting Emissions from Livestock Production
Based on a review of the literature, livestock production affects emissions of GHGs both
directly and indirectly. The indirect emissions, i.e., those through crop production, are
already included in the discussion above. In this section only the direct emissions from
livestock production are included.
2.3.2.1 Carbon Dioxide
The direct linkage between livestock production and CO2 emissions is through the
respiration process of farm animals. In addition, animal excretions/wastes (and manure
applied to crop production) contribute to the level of CO2 emissions.
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2.3.2.2 Methane
Based on the review of the literature, several factors can be identified that affect the emission
of methane from livestock operations. A list of factors, further classified into management
factors and environmental factors, is shown in Table 2.8.
Table 2.8: Factors Affecting Methane Emissions from Animal Production Practices
Management Practices
Environmental Factors
Type of animal
Temperature
Size and weight of the animal
Precipitation
Type of feed and other dietary inputs
Genetic characteristics of animals
Type of building and shelter used
Manure handling systems and use of chemicals
Building heating equipment used
Building cooling equipment used
According to Burke and Lashof (1989), methane emissions levels are primarily affected by
the quantity and type of feed material, body weight, energy expenditure, and enteric
ecology. In addition to the type of animals, emissions of methane are affected by weather,
leading to different seasonal patterns (Mathison et al 1997). Using Rusitecs (artificial rumen
systems), Dong et al. (1997) showed that use of chemicals reduces CH4 emissions.
Another major source of methane emissions is animal excretions/wastes. Associated with
these are the manure handling systems, which are a major factor affecting emission levels, as
suggested by McCaughey, Wittenberg, and Corrigan (1997), and Pattey et al. (1997a).
Management practices, such as the use of chemicals, are reported to decrease methane
emissions.
2.3.2.3 Nitrous Oxide
Based on available information, no direct linkage between livestock production and
emissions of nitrous oxide exists. Such emissions from the application of manure to crop
lands are accounted for above under Section 2.3.1.3. However, a certain amount of indirect
linkages could exist, since some livestock operations require various forms of energy inputs.
2.4
Summary
In this chapter a discussion of factors affecting emission levels of major GHGs was presented.
Since the nature of factors related to crop production and livestock production are
substantially different from each other, the estimation of agriculturally- induced emissions of
GHGs should be carried out separately. Furthermore, within each of these production
activities, the nature of factors affecting emission levels for each gas is such that an aggregate
approach is not going to provide realistic estimates of total emission levels. These, together
with other methodological considerations, were used in the design of the estimation
procedures, discussed in the next chapter.
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Chapter 3: Analytical Framework
In this chapter, the methodology used for estimating the total emissions of GHGs resulting
from agricultural activities is described. As mentioned above, this involved developing a
model called C.E.E.M.A. This model has two sub-models: One, an economic planning and
resource allocation sub-model, called CRAM; and two, a GHGs emission estimation submodel, called GHGE sub-model, which together with CRAM, was used to estimate the total
agriculturally-induced emissions. Since CRAM is capable of estimating impacts of changes
in economic policies, appending the GHGE sub-model provides a methodology to assess
both the economic effects and the environmental effects, measured in this study solely in
terms of emissions of major GHGs.
This chapter is divided into four sections. Section 3.1 includes a review of pertinent studies,
reporting either methodology or results for agriculturally-induced emissions of GHGs. Since
CRAM has been described in Horner et al. (1992), further discussion were considered not
warranted. Therefore, in Section 3.2, considerations involved in the development of the
GHGE sub-model are presented. A conceptual method of estimation is reported in Section
3.3, which is followed by a specification of the GHGE sub-model in Section 3.4.
3.1
Review of Previous Studies
The study of GHGs emissions from agricultural activities has been brought into focus since
the climate change studies carried out for the IPCC. A summary of these results is presented
in Watson et al. (1990). The Watson et al. study evaluated the quality of information on the
process, as well as on the major sources and sinks. The review indicated that the mechanisms
underlying the release of methane and nitrous oxide are, relatively speaking, poorly
understood. Furthermore, even less well understood is the extent to which effective
mitigative measures could be designed by changes in the farming practices. In spite of these
challenges, a significant number of strides have been made in understanding these processes.
Since much of the IPCC work is global in nature, and includes only major sources and sinks
of GHGs in a global perspective, the usefulness of such estimates for a specific country or
region is somewhat limited. Several studies have addressed the GHG emissions at a less
aggregate level, at a country or regional level. Kreileman and Bouwman (1994) developed a
GHG emission model, as a part of an integrated model IMAGE 2.0, Integrated Model to
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Chapter 3
Assess Greenhouse Gases Emissions. Emission levels were linked to changes in land use or
land cover. The model generated estimates for various continents as well as global maps. A
country-level evaluation was not presented as a part of this integrated model, although since
the signing of the FCCC, interest in such an exercise has increased27.
In the U.S., estimation of GHGs has been carried out both as a part of policy evaluation, as
well as for understanding the emissions, and development of mitigative measures. Faeth
(1995) included GHG emissions as one of 10 environment indicators for evaluation of various
policy scenarios. However, Faeth’s methodology for the estimation of GHG emissions was
not described in detail. A descriptive evaluation of agriculturally-induced emissions is
provided by Greene and Salt (1993), whereas a systematic evaluation of various emissions
sources in the U. S. has been provided by Jackson (1992).
In Canada, an estimation of agriculturally-induced emissions of GHGs was carried out under
the Canada’s Green Plan. A five-year initiative of “Greenhouse Gas Research in Agriculture”
was undertaken to “find ways to quantify the sources and sinks of GHG and to develop
practical means to minimize the Canadian agricultural sector’s contribution to the problem
and maximize its contribution to the solution”.28 Under this initiative, various studies
estimated sources and sinks of the three GHGs. A balance for the three gases has been
developed by Jaques (1992), and by Liu (1995), and more recently by Desjardins (1997). In
addition, the contribution of agriculture to emissions of CO2 was estimated by Curtin et al.
(1997). Similarly, CH4 emissions were estimated by Mathur (Undated), McAllister (1997),
and by Desjardins (1997), and for N2O, by Gleig and MacDonald (1995). These studies served
as a basis for identifying various sources and estimating some of the emission coefficients
which were used in the GHGE sub-model of the C.E.E.M.A..
3.2
3.2.1
Considerations Involved in the Development of the GHGE SubModel
Scope of Agriculture Production Activities
The following activities, as part of agricultural production, contribute to the release of GHGs:
•
use of farm cash inputs in the production of crop and livestock products;
•
direct emissions of livestock on farms; and,
•
management activities for crops and livestock production leading to direct
emissions of GHGs.
This means that the following types of GHG emissions are excluded from this study:
•
transportation of farm products from farm gate to an assembly point;
•
procurement of farm inputs, if undertaken by producers;
27. For example, India initiated an assessment of greenhouse gases emissions, including the role played by
agriculture, as reported by Mehra and Damodaran (1993).
28. For details on various studies under the Green Plan, see Agriculture and Agri-Food Canada (1997), p. 13.
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•
any other farm related activity not included above; and,
•
family or personal related uses of sources of emissions.
In addition, emissions (positive or negative) from non-cultivated lands (wetlands,
shelterbelts, among others) were also excluded. Furthermore, the emissions of GHGs during
the manufacturing and storage of the farm inputs (such as fertilizer, chemicals, farm
machinery and equipment) are also excluded. Forward linkages of agriculture with agriprocessing industries are also not included in this study.
3.2.2
Considerations in the Design of the Model
The designing of the C.E.E.M.A. was guided by the need for integrating the GHGE submodel with the CRAM, which has its own set of specifications of agricultural activities. In
order to make the two sub-models compatible, the following considerations guided the
development of the GHGE sub-model:
•
Since each of the three GHGs is affected by a specific set of factors and
agricultural practices, estimation of total emissions needs to be carried out on an
individual greenhouse gas level.
•
CRAM is a disaggregate model over various provinces and, for some provinces,
even over sub-regions. The GHGE sub-model should, therefore, be
disaggregated over provinces, and over sub-regions, where applicable.
•
Since the magnitude of crop or livestock production activities varies from region
to region, and since these are major variables determining greenhouse gas
emission levels, separate modules need to be specified for crop production and
livestock production.
•
Since the type of crop or livestock is a major determinant of emission levels,
disaggregation of total production activities by type of crop or livestock is
necessary.
•
Within a crop or livestock production activity, one can hypothesize a number of
activities that may give rise to emissions of one gas or another. Thus, it is
necessary to identify various sources (as well as sinks) of GHGE, and to base
estimates of emission levels on such a disaggregated approach.
These considerations suggest that the GHGE sub-model, by necessity, has to be
disaggregated in nature. Two separate modules need to be estimated: One, for crop
production and the other for livestock production. Each module needs to be specified over
production regions, for each of the three GHGs, and by major agricultural activities that lead
to the emissions of one or more of these gases.
3.3
Conceptual Method of Estimation
An essential part of the design of the GHGE sub-model was the identification of the various
agricultural activities which lead to emission of the three GHGs, and methodology for
estimating the ECs. This is presented here. However, since the designing of the GHGE sub-
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Chapter 3
model required specification of regions and type of production activities (crop and
livestock), and compatibility with CRAM, these specifications were made identical to those
in CRAM. These are described in detail in the next section (section 3.4) of this chapter.
3.3.1
Conceptual Linkages between Agricultural Production Activities and
Emissions
Development of linkages between emissions of GHGs and agricultural activities was carried
out in two steps. For each of the three gases, various production-specific farm activities were
identified, and then the linkages between the identified activities and enterprises were
hypothesized. Step one resulted in three charts, shown in Figures 3.1 to 3.3.
Figure 3.1: Major Sources of Carbon Dioxide Emissions from Agricultural Production
Actitivities
ATMOSPHERE
CHEMICALS
LOSS OF
SOIL ORGANIC
MATTER
LIVESTOCK
EXCRETIONS /
WASTES
FOSSIL FUELS
PLANT
PHOTOSYNTHESIS
BIOMASS
BURNING
TILLING LAND
LIVESTOCK
MANAGEMENT
MANURE
CROPLAND and PASTURELAND
(SOILS)
For carbon dioxide, as shown in Figure 3.1, eight major linkages can be identified between its
emissions and activities related to agricultural production. These include photo-synthesis as
a sink, while the other seven are sources. Among various sources, tillage operations affecting
release of soil carbon, and use of various agricultural inputs, are significant.
For methane emissions, only three sources can be identified, as shown in Figure 3.2,. These
are all related to livestock production, although there is a link between livestock and crop
enterprises through the use of manure.
Nitrous oxide emissions are more complex because these are derived from many sources,
and because of the interdependence of crop and livestock production activities. Eight such
sources are identified in Figure 3.3. Two of these are directly related to livestock production,
and the other six to crop production activities. Among these, use of fertilizers and tilling of
land are the most significant ones.
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Figure 3.2: Major Sources of Methane Emissions from Agricultural Production
Activities
ATMOSPHERE
FARM ANIMALS
LIVESTOCK
MANAGEMENT
LIVESTOCK
EXCRETION/
WASTE
MANURE
CROPLAND and PASTURELAND
(SOILS)
Figure 3.3: Major Sources of Nitrous Oxide Emissions from Agricultural Production
Activities
ATMOSPHERE
LOSS OF
SOIL ORGANIC
MATTER
BIOMASS
BURNING
FOSSIL
FUELS
CROP
RESIDUES
FERTILIZERS
TILLING
LAND
MANURE
LIVESTOCK
EXCRETIONS/
WASTES
NITROGEN
FIXING
CROPS
HERBICIDES
CROPLAND and PASTURELAND
(SOILS)
3.3.2
Specification of Linkages
The relationship between emissions of GHGs and agricultural production activities was
based on a review of various past studies of estimation of GHG emission levels. Each of the
two modules — Crop and Livestock — were specified separately.
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3.3.2.1
Crop Production Module
Various agricultural production-related activities were identified as a potential source or
sink of GHGs. Of these, twelve were selected for inclusion in the GHGE sub-model. The
relationship between these twelve activities, their relevance to crop production, and their
possible relationship with emission of the three GHGs were hypothesized further. These are
shown in Table 3.1.
Table 3.1: Conceptual Linkages between Emissions of Greenhouse Gases and Crop
Production Activities
Activity
No.
Carbon
Dioxide
Description
Methane
Nitrous Oxide
1
Photosynthesis
#1(Sink)
2
Soil Organic Matter*
#2
#8
3
Fossil Fuels (Incl. crop
management activities)
#3
#9 (Minor)
4
Biomass Burning
#4
#10
5
Crop Residues
#11
6
Use of Fertilizers
#12
7
Use of Manures
8
Nitrogen Fixing Crops
9
Chemicals
10
Farm Animals
11
Livestock Excretions / wastes
12
Livestock Management
#5
#7
#13
#14
#6
#15(N.E.)(Minor)
Note: Dark shaded cells are hypothesized to be not relevant for crop production.
Light shaded cells were excluded on account of being of minor importance.
*Loss of soil organic matter is related through tilling of land.
Of these activities, photosynthesis creates a sink for CO2. Although agricultural soils can
serve as sinks for carbon and nitrogen, these were not identified as sinks in the GHGE submodel. Instead, loss of soil carbon (or nitrogen) in the form of CO2 (or N2O) was estimated on
a net loss basis, making soils either a source or a sink, for GHGs. One should also keep in
mind that photosynthesis is one of the components of the carbon cycle, as shown in Figure
3.4. In order to define this cycle, one must start with the boundary of the ecosystem, since all
flows of CO2 are relative to this. Photosynthesis converts CO2 to organic C, but plants also
respire CO2. A portion of the plant organic C is converted to SOM, some of which is released
through tilling of the land. One should therefore, be careful to conclude from this that crop
production related photosynthesis is a net sink of CO2.
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Use of agricultural inputs, fertilizer, manure, chemicals, and fuel for the operation of farm
machinery, are the next major source of GHG emissions. In fact, manure provides the link
between the crop production and livestock production modules. However, on account of
poor information available on the manure handling systems and on practice of manure
applications, these emissions were not included in this module29. Since manure is the only
source of emission of methane from crop production, and is excluded from this estimation,
this means that methane emissions from crop production are zero. This is not to suggest that
these emissions were totally excluded from the GHGE sub-model. In fact, all emissions from
the livestock excretion/wastes were included under the Livestock Production Module.
Figure 3.4: A Schematic Representation of “Carbon Cycle” involving Crop
Production
Net Annual Exchange of CO2 by Crops
(Tg)
Energy
9
CO2
520
Product
90
300
130
130
Ecosystem
boundary
Soil organic
matter
Note: Figures shown are symbolic and not actual estimates necessarily.
Source: Ray Desjardins, Personal Communications, 1998.
3.3.2.2
Livestock Production Module
Of the twelve agricultural activities, only three are relevant to livestock production: farm
animals, animal excretions/wastes and their handling, and use of fossil fuels for livestock
management. Linkages between them and GHG emissions are shown in Table 3.2.
29. As noted later on, these emissions were included in the Livestock module.
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Chapter 3
Farm animals, particularly the ruminants, produce methane through microbial decomposition in the intestines, called enteric fermentation. Animal excretions/wastes are related to
the generation of all three gases. Since a part of these excretions/wastes becomes an input
into the crop production enterprises (through manure), and given that emission of GHGs
through manure was not estimated, all emissions were accounted for in this Module.
In addition, certain livestock enterprises require energy inputs for the production of farm
output. These inputs are included under livestock management, and include heating or
cooling of buildings, ventilation, and some direct production-related operations, such as
milking of dairy cows, and distribution of feeds.
3.3.3
3.3.3.1
Estimation of Agriculturally-Induced Emission Levels
Considerations Involved
The estimation of GHG emissions from Canadian agriculture is based on several
assumptions or considerations. Many of these are suggested by the studies reviewed and
presented in the previous chapter. The ECs in this study reflect the following characteristics:
•
The ECs in this study are, in most cases, direct coefficients30. Thus, only that part
of the total emissions that is a direct result of the said activity is captured by these
coefficients. The ECs do not reflect that part of the emissions of the GHGs that is
embodied (i.e., those emissions that result from the production and marketing of
the inputs used in farming).
•
The ECs are static in nature. No effort is made here to capture the dynamic or
cumulative effect of various agricultural activities on the GHG emissions.
•
The ECs reflect the annual rate of emissions. No seasonal distribution of emission
levels is taken into account.
•
The ECs are based on secondary information. No primary data were collected in
the estimation of these coefficients.
•
The ECs reflect differences in Canada's different ecological regions, subject to
availability of data and information.
•
The estimated ECs for crop production are based on crops, rotations, and other
cultural practices as reflective of the situation as it existed in 1994. In some cases,
data for 1994 were unavailable, and a close time domain was used instead.
•
The estimated ECs for livestock production reflect the livestock mix of various
parts of Canada, as well as other management practices.
The above characteristics of the ECs should be kept in mind while making interpretations to
the total GHG emissions.
30. In addition to the direct emissions from crop and livestock production, some emissions of GHGs are related
to other farm operations, which are not included in this study.
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Table 3.2: Conceptual Linkages between Emissions of Greenhouse Gases and
Livestock Production Activities
Activity No.
Carbon
Dioxide
Description
1
Photosynthesis
2
Soil Organic Matter
3
Fossil Fuels
4
Biomass Burning
5
Crop Residues
6
Use of Fertilizers
7
Use of Manures
8
Nitrogen Fixing Crops
9
Chemicals
10
Farm Animals
11
Livestock Waste
#1
12
Livestock Management
#2
Methane
Nitrous Oxide
#3
#4
#5
#6
Note: Dark shaded areas are hypothesized to be not relevant for livestock production.
3.3.3.2
Estimation of Total Emissions of Greenhouse Gases
The estimation of total emissions of GHGs, which are agriculturally-induced, was carried out
separately for each GHG. The total Canadian emissions is simply a sum of provincial (or
regional) emissions from a particular agricultural activity. For each of the gases, total
regional emissions were sub-divided into two sources/types of emissions, crop production
and livestock production, as shown in equation (3.1), each of which was estimated in its own
respective module. Total GHG emissions may be expressed as:
TAIEGrg
= CRPEGrg + LSPEGrg
(3.1)
where
TAIEGrg
= total agriculturally-induced emissions of the gth greenhouse gas in the
rth region,
CRPEGrg
= crop production-based emissions of the gth greenhouse gas in the rth
region,
LSPEGrg
= livestock production-based emissions of the gth greenhouse gas in the
rth region,
g
= various greenhouse gases (CO2, CH4, and N2O)
r
= various regions.
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Chapter 3
Thus, on account of the scope of this study, total agricultural emissions are caused by either
crop or livestock production. Each of these needs to be estimated separately. In each of the
two modules, total emissions were a product of the scale of economic activity and an average
EC. Estimation of the ECs was, therefore, the central focus of the study. The development of
these coefficients is described in the next two sub-sections.
3.3.3.3
Estimation of Crop Production Induced Emissions
In order to estimate total crop production-induced GHG emissions, total farm lands were
classified into three types: crop lands, hay lands, and pasture lands. Crop lands were
devoted to the production of cereals, oilseeds, pulse crops, and other cash or non-cash crops.
Hay lands were similar to crop lands, except the production activity involved various types
of forage crops. The pasture lands were either improved pastures or unimproved pastures.
Thus, the regional total GHG emissions were estimated as a total of emissions from the three
types of lands, such that:
CRPEGrg
= CRPEG 1rg + CRPEG 2rg +CRPEG3rg
(3.2)
where
CRPEGrg
= total emissions of gth gas in the rth region,
CRPEG1rg
= emissions of gth gas from crop lands in the rth region,
CRPEG2rg
= emissions of gth gas from hay lands in the rth region, and
CRPEG3 rg
= emissions of gth gas from pasture lands in the rth region.
All these emissions were estimated using a specific methodology, discussed below.
Emissions from crop lands were estimated as a weighted sum of emissions coefficients for
each crop activity, times the scale of operation. Let different crops be denoted as subscript p:
P
CRPEG1rg ' j ECC1prg ( S1pr
p'1
(3.3)
where
P
= number of crop activities
ECC1prg
= emission coefficient for pth crop per unit of land base for the gth gas in
the rth region, and,
S1pr
= scale of operations for the pth crop in the rth region.
The weighted EC for the pth crop activity, ECC1prg, was based on a sum of emission
coefficients for various GHG emission activities listed in Table 3.1 (denoted as subscript
“a” -- {1,..., 12}) that are involved in the production of that crop.
ECC1prg ' j ECC1parg
12
a'1
30
(3.4)
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where
ECC1parg
= emission of greenhouses gases for the pth crop, ath production activity
for the gth gas in the rth region.
GHG emissions from hay lands were estimated using a methodology similar to that above.
No distinction was made between the establishment year and the production year of the
forage crop. Estimation of coefficients was similar in nature as discussed above. Estimated
emissions from pasture lands were limited to those directly related to vegetation growth and
management practices. All relevant activities, as listed in Table 3.1, were included initially.
If some activities were carried out periodically, allowances were made for such practices.
Since pasture and hay lands produce the very same product, forage, methodology for
estimation of their emissions was identical to that for hay lands.
3.3.3.4
Emissions Induced by Livestock Production
Two factors relevant to the emissions of various GHGs in the context of livestock production
are: number and type of livestock, and environmental factors, which vary from region to
region. Both direct and indirect emissions (through the use of animal excretions/wastes)
were related to these two factors in this study. Regional differences were recognized
through the nature of livestock enterprises in various regions. At this time, regional
differences in the rate of emissions (through climatic or other factors) could not be
incorporated due to lack of data.
The total Canadian emissions from livestock operations were simply a sum of such emissions
in various provinces (production regions). For a given region, the total emissions of a GHG
from livestock production can be shown as:
LSPEGrg ' DLSrg % WLSrg % LMArg
(3.5)
where
LSPEGrg
= emissions of gth GHG from livestock production in region r;
DLSrg
= direct emissions of gth greenhouse gas from livestock production in the
rth region
WLSrg
= indirect (through animal excretions/wastes) emissions of gth greenhouse
gas from livestock production in the rth region; and,
LMArg
= direct emissions of gth greenhouse gas from livestock management
activities in the rth region
Canadian Economic and Emissions Model for Agriculture: Report 1
31
Chapter 3
Direct emission levels were estimated as a weighted average of emissions from various types
of livestock on farms in various regions, as shown in equation (3.6):
N
DLSrg ' j EClrg ( S lr
l'1
(3.6)
where
EClrg
= emission coefficient for direct emissions for the gth greenhouse gas by lth
type of livestock in rth region; and,
Slr
= number of lth type of livestock on farms in the rth region
The indirect emissions were also prorated on the basis of structure of livestock operations in
various regions. Thus, for a given region, such emission levels were simply a product of size
of production activity and the respective emissions from a given type of livestock operation.
Since livestock and crop production activities are interdependent through the use of manure,
an adjustment in these emissions is necessary to avoid double-counting.
N
WLSrg ' j IEC lrg ( [1&ADJlrg] ( Slrg
l' 1
(3.7)
where
IEClrg
= indirect emission coefficient for the gth greenhouse gas by the lth type
livestock in rth region; and,
ADJlrg
= proportion of livestock waste by lth type of livestock applied as manure for
the gth greenhouse gas, in the rth region.
The last component of emissions for livestock operations in equation 3.5 is related to
livestock management. This component was estimated in a similar manner as the direct
emissions in equation (3.5). These emissions include those produced through activities such
as: heating and cooling of buildings for various livestock (particularly for dairy cattle, exotic
beef cattle, hogs, and poultry); and, use of mechanical devices for feed handling, and for
manure handling and applications.
3.4
Specification of GHGE Sub-Model
The GHGE sub-model contains ECs for each of the three GHGs. Method of estimation for
these coefficients is the subject of the next chapter. As noted above, these coefficients are
linked to the estimated scale of agricultural activity (crop or livestock production) in various
CRAM regions. Specification of the GHGE sub-model, thus, would have to be compatible
with the specification of the CRAM. In this section, these specifications are described.
3.4.1
Specification of Regions
The regionalization in CRAM is based on a combination of availability of information, and
on the homogeneity of production conditions. For these reasons, livestock production and
crop production activities have a different regional character. For livestock production,
32
Canadian Economic and Emissions Model for Agriculture: Report 1
Analytical Framework
Canada is divided into ten provinces31. The crop production regions are the same as the
provinces, except for the Prairies where each province is sub-divided into crop districts. The
number of these regions and sub-regions is listed in Appendix A, Table A.1.
3.4.2
3.4.2.1
Specification of Production Activities
Crop Production Activities
Crop production activities were specified for each crop production region in an identical
manner. These are listed in Appendix A, Table A.2. A total of 109 activities were specified,
which included the following major crops: barley (feed and malting), canola, corn (grain and
silage), field peas, flax, lentils, oats, potatoes, soybeans, and wheat (spring as well as durum).
The activities also included summerfallow, forage and pasture (both improved and
unimproved).
3.4.2.2
Livestock Production Activities
Four types of livestock production operations were included: (1) beef; (2) dairy ; (3) hog; and
(4) poultry. For each of these operations, various type of products produced (intermediate or
final) were specified. A total of 30 such products were included, which are shown in
Appendix A, Table A.3.
3.5
Overview of the Integrated Model
The GHGE sub-model was used together with CRAM in an integrated manner. CRAM is a
regional linear programming model of Canadian agriculture. It simulates production,
marketing and transportation of major agricultural (crop and livestock) commodities
produced in Canada (and its various regions) within the constraints of available land
resources (in each region) and final demand for the products.
The nature of this linkage between CRAM and the GHGE sub-models is shown in Figure 3.5.
The GHGE Sub-model uses the output generated by the CRAM. The nature of this output
includes the level of production that is determined by CRAM to be optimal. The optimal
level is determined when consumer surplus and producer surplus (return over cash costs)
are maximized under the given level of available resources. The emissions levels are
subsequently determined by the GHGE sub-model through the use of the ECs. Development
of these ECs is the key to the estimation of GHG emissions from Canadian agricultural
activities. It should be noted that the nature of feedback between the two sub-models is oneway, from the CRAM to the GHGE Sub-model. It is conceivable that in the long-run, the
feedback effects may be two-way. However, the effect of the GHG emissions on agriculture
is not included in the present study, since most of the estimates of climate change impacts
project them to be experienced around 2060.
31. The Northwest Territories and Yukon are not included in the model.
Canadian Economic and Emissions Model for Agriculture: Report 1
33
Chapter 3
Figure 3.5: An Overview of the Canadian Economic and Emissions Model for
Agriculture (C.E.E.M.A.)
RESOURCE
AVAILABILITY
BY TYPE
DEMAND FOR
PRODUCTS
CROP
MODULE
ECONOMIC SUB-MODEL
CANDIAN REGIONAL AGRICULTURE MODEL
LIVESTOCK
MODULE
PRICES
PRODUCER
SURPLUS
AREA UNDER
CROPS
CROP
YIELDS
MANAGEMENT
BASIC
HERD
LEVEL OF
LIVESTOCK
CROP EMISSION
COEFFICIENTS
GREENHOUSE GASES
EMISSION SUB-MODEL
LIVESTOCK EMISSION
COEFFICIENTS
EMISSIONS OF GREENHOUSE GASES FROM
CROPS
LIVESTOCK
34
Canadian Economic and Emissions Model for Agriculture: Report 1
Chapter 4: Methodology for the
Estimation of Emission Coefficients
In the previous chapter, the basic structure of the two GHGE modules, crop module and
livestock module, was described. A central and essential feature of these modules are
emissions coefficients for various regions, production activities, and various agricultural
activities that lead to GHG emissions. As noted, these coefficients were estimated using
secondary data and no primary data were collected. Sources and bases for the estimates are
provided in this chapter. This chapter is divided into two major parts: Section 4.1 provides
details on the crop emission coefficients, and Section 4.2 provides the same for the livestock.
Furthermore, the crop module discussion is divided into two sub-sections, one each for CO2,
and N2O, whereas the discussion for the livestock module has three sub-sections, one each
for CO2, CH4 and N2O.
4.1
Emission Coefficients for Crop Production
Although crop production activities can contribute to the emissions of all three greenhouse
gases, only CO2, and N2O were estimated. The reason for excluding methane emissions from
crop production was the lack of data on: the amount of animal excretions/wastes applied as
manure in different production regions, the crops that receive such treatment, and,
distribution of crops by type of manure (e.g., pig manure versus dairy manure).
Under the above limitations, although 12 sources of GHG emissions related to crop
production activities were identified in Table 3.132, three were excluded since they are
relevant to livestock production activities. Six of the remaining nine sources were linked to
emissions of CO2, and eight to emissions of N2O. Method of determining the ECs for each of
these sources is described in this section.
32. In Table 3.1, each of the production activities that was hypothesized to be linked with the GHG emissions
was numbered. Twelve such cells were identified.
Canadian Economic and Emissions Model for Agriculture: Report 1
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Chapter 4
4.1.1 Carbon Dioxide
Of the six crop production activities listed in Table 3.1 as potential sources of CO2 emissions,
one was a sink, while the other five were, on a net basis, a source. Three sources relate to crop
production inputs, while the other two to management practices. Each of these is discussed
in this sub-section.
4.1.1.1 Photosynthesis
Liu (1995) estimated CO2 emissions (intake) related to various crops, using dry matter as the
primary factor. These emissions vary by crop type, since crop yields are different, and
because their respective water contents also vary. On a dry matter equivalent, 0.45 gram of
carbon per gram of dry matter is used by plants through carbon fixation.
The estimation of emission (in this case intake) coefficients for photosynthesis was divided
into two parts: coefficients for crop residues that remain in the field, and coefficients for the
seed (grain or other products) that are removed. The first coefficient was estimated using the
following equation:
ECC
PHTSpr
' [YLDpr ( (1 & Wp) ( BMSp] ( C ( 3.6664
(4.1)
where
ECCPHTSpr
= emission (Intake) coefficient for carbon dioxide through
photosynthesis by pth crop plants, in tonnes of CO2 per ha;
YLDpr
= yield of the pth crop in t ha-1 in the rth region;
Wp
= water contents, expressed as a proportion of plant biomass;
BMSp
= biomass factor for the pth crop; and
C
= carbon content of dry matter.
The last coefficient (3.6664) was the conversion factor between carbon and carbon dioxide.
The moisture contents and biomass factors used in the study are shown in Table 4.1. The
second emission (intake) coefficient, one for grain, was also estimated using equation (4.1),
except that the BMS for all crops was set equal to one.
In order to estimate the EC using equation(4.1), data on yields for various crops, forages, and
pastures in different regions were required. These yields were taken from the CRAM input
files for the year 1992 (the latest available). In order to facilitate the estimation of these
coefficients, some assumptions had to be made on account of lack of information. These are
listed as follows:
36
•
Water contents and biomass factors for pastures, potatoes, and corn silage were
not available. These were respectively equated to: tame hay, sugar beets, and
fodder corn.
•
Durum wheat was assumed to be similar to spring wheat in terms of the biomass
factor and moisture content.
Canadian Economic and Emissions Model for Agriculture: Report 1
Methodology for the Estimation of Emission Coefficients
•
For Western Canada, yields for oats were not available. For Saskatchewan, these
were estimated using data from Saskatchewan Agriculture and Food (1995), for
various soil zones and crop districts. For other provinces, oats yields were
estimated using a ratio between barley and oats yield for a given soil zone in
Saskatchewan.
Estimated yields, along with water contents and biomass factors, were used to estimate the
CO2 for plant biomass and grain. Both of these were combined together to obtain a single EC
for photosynthesis.
Table 4.1: Input Data for the Estimation of Emission Coefficients for Photosynthesis
by Crops
Crop
Dry Matter Equivalent*
Biomass Factor (kg of Total
Biomass per kg dry yield)
Barley
0.12
2.12
Corn
0.05
2.46
Durum
0.14
2.15
Flax
0.12
2.15
Field Peas
0.12
2.15
Hay
0.05
1.30
Lentils
0.12
2.15
Oats
0.11
3.44
Other Crops
0.14
2.15
Pasture
0.05
1.30
Potatoes
0.77
2.15
Soybeans
0.10
2.46
0
0
Unimproved Pastures
0.05
1.30
Wheat
0.14
2.15
Summerfallow
* Dry matter equivalent = 1 - Proportion of water in the biomass
Source: Compiled using data presented by Jackson (1992).
4.1.1.2 Loss of Soil Organic Matter
Change in SOM is an important part of the carbon balance. Carbon stored in the soil is a
dynamic process and is affected by a complex set of factors. This has prompted scientists to
develop models of soil-carbon dynamics, such as CENTURY Model33. This model has been
validated for Canadian conditions, and results from these applications are reported by
33. The CENTURY Model is a site-specific computer simulation of the dynamics of SOM. This model was
developed in the U.S. and has been validated under short- and long-term field experiments in several
countries, including Canada. For details of the model, see Parton et al. (1993).
Canadian Economic and Emissions Model for Agriculture: Report 1
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Chapter 4
Smith, Rochette and Jaques (1995), and Smith et al. (1995). The latter study also reported rate
of loss of soil organic carbon in different Canadian provinces and in different soil zones.
These details are shown in Table 4.2 for various Canadian provinces, and in Table 4.3 for
important soil types.
Table 4.2: Level of Soil Carbon Loss (from 0-30 cm depth) to the Atmosphere from
Cultivation of Crops, Canada
Rate of Change in kg ha-1 per Annum
Province/Region
1980
1985
1990
Atlantic
-12.5
-9.6
4.3
Quebec
-40.2
-37.2
-34.5
Ontario
-6.6
-5.7
-4.1
Manitoba
-76.7
-73.2
-66.1
Saskatchewan
-39.3
-36.5
-22.5
Alberta
-84.0
-79.9
-74.5
British Columbia
-33.7
-31.1
-16.1
Source: Smith et al. (1995), p. 11.
Table 4.3: Level of Soil Carbon Loss (from 0-30 cm depth) to the Atmosphere by Soil
Type, Canada
Rate of Change in kg ha-1 per Annum
Soil Type
1980
1985
1990
Brown Chermozemic
-26.9
-27.4
-22.6
Dark Brown Chermozemic
-38.4
-35.6
-15.6
Black Chermozemic
-94.8
-89.1
-84.1
Dark Gray Chern./Luv.
-77.5
-69.7
-59.6
Gray Brown Luvisolic
-8.7
-9.3
-10.1
-22.3
-25.5
-20.1
-9.7
-8.6
-1.7
Gray Luvisolic
Greysolic
Source: Smith et al. (1995), p. 13.
The estimates of soil carbon loss on a provincial basis or by soil type, although providing an
excellent start, are appropriate only for aggregate studies. For the purposes of this study,
however, they were considered unsuitable. In addition, soil organic carbon loss is affected by
two other factors: type of crop grown and rotation followed, and nature of tillage operations.
Coxworth et al. (1995, p. iv) suggested that relative to conventional tillage, minimum tillage
and zero tillage generate 95% and 86%, respectively, of the emissions of carbon. In CRAM,
for the three Prairie provinces, various crops can be grown under one of three tillage regimes:
38
Canadian Economic and Emissions Model for Agriculture: Report 1
Methodology for the Estimation of Emission Coefficients
intensive, moderate, and zero (or no) till. Since these factors may have a profound effect on a
region’s rate of soil carbon loss, their incorporation was considered an important feature for
the crop module.
In order to estimate soil carbon loss by production regions, crops, and tillage practices, a
different methodology was devised. Smith, Rochette and Jaques (1995, Appendix B)
provided details of various CENTURY model runs made at the soil polygon level for each of
the ten provinces. For each province, major rotations were defined, and in addition, for some
polygons in the three Prairie provinces, rotations included both conventional tillage and no
tillage systems.
Although it was technically possible to classify various soil polygons included in the results
reported by Smith, Rochette and Jaques (1995) by CRAM production regions, and use
relative weights of various rotations for each of these regions, these classifications were
beyond the scope of this phase of activity. A somewhat short-cut method was devised. This
methodology along with various assumptions made is described below.
•
For provinces with no further disaggregation (British Columbia, Ontario, Quebec,
three Atlantic provinces, and Newfoundland), all soil polygons were used to
derive an emission coefficient. The EC was a weighted average of all soil
polygons, weighted by relative size of the polygon. For the three Prairie provinces
and for each of the 22 crop districts, the larger soil polygons34 were selected. The
selected polygons were used as representative for the entire crop district. It was
further assumed that the rotations included for the polygon were representative
of the region.
•
For a given crop district (or province), the EC for each crop was derived from the
results of the CENTURY model run for a rotation. All crops included in that
rotation were given an identical coefficient. For example, if the rotation was
“CWF – canola, wheat, fallow”, and it had a soil carbon loss of 6 grams per square
meter (gm m-2), all three crops, wheat on stubble, canola on fallow, and fallow —
were given the same coefficients.
•
If the results of the CENTURY model run included more than one rotation
involving a crop, a weighted average, using the size of the polygon as the
weights, was estimated.
•
For some regions, some crops were not included in the CENTURY model runs.
These included durum wheat, other crops on stubble or summerfallow, oats,
pasture, unimproved cultivated pastures, and corn silage. In these cases
coefficients were approximated using the following rules:
Rule 1:
If information on fallow rotation was not available, the ECs were equated
to those for the stubble rotations for that soil polygon.
Rule 2:
Corn silage was equated to corn grain.
Rule 3:
Other crops on stubble or fallow were taken as an average of all rotations
for the selected soil polygon.
34. The choice of this polygon was decided by the rotation. For each rotation and tillage system, a different
polygon was therefore, selected.
Canadian Economic and Emissions Model for Agriculture: Report 1
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Chapter 4
•
Rule 4:
Coefficient for the unimproved pasture was apportioned using the
coefficient for pasture on the basis of forage yield differences.
Rule 5:
For some crop districts, if a crop was not included within the chosen soil
polygon, estimates were taken from an adjoining (but similar soil zone)
polygon.
As noted above, the CENTURY model runs included, in some soil polygons, two
types of tillage practices: conventional tillage and no till. For this study,
conventional tillage was assumed to be the same as the intensive tillage in CRAM.
The coefficients for no till were used for the no till systems in CRAM. However,
two problems that were encountered in this context: One was that for some crop
districts, there was no information for the two types of tillage operations. The
other was there were no data from the CENTURY model runs for the minimum
tillage crops in CRAM. To solve these problems, two further rules were applied:
Rule 6:
For the polygons, and crops for which CENTURY model results for
conventional and no tillage systems were available, the coefficient for
minimum tillage was estimated as a simple average of the two emission
levels. This is consistent with the results presented by Coxworth et al.
(1995) for selected rotations.
Rule 7:
For the polygons with no such information, CENTURY model runs were
assumed to apply to conventional tillage, and the coefficients for the other
two tillage systems were estimated as follows: minimum tillage: 95% of
conventional tillage; and, no tillage, 90% of conventional tillage.
Estimated coefficients were compared against the provincial average coefficients as reported
by Smith, Rochette and Jaques (1995, p. 18). This comparison is shown in Appendix B. This
study estimated the emissions of C from soils at 49.36 kilograms per hectare per year (kg ha-1
y-1), against Smith, Rochette and Jaques’ estimate of 39.8 kg ha-1 y-1. Comparison was also
made on a provincial basis and the coefficients were found to be fairly close, except for
Manitoba, and British Columbia.
4.1.1.3 Burning of Fossil Fuels
Canadian farms use three types of fuels for farm business operations: diesel oil, natural gas,
and electricity35. Diesel oil is related to crop production, and the operation of farm machinery
used for various cropping activities. Natural gas and electricity are used more for other farm
operations related to crop production. For this reason, total emissions were divided into two
parts: direct emissions; and indirect emissions.
Direct Fuel Use on Farms for Crop Production
Several factors were used in the estimation of the ECs for direct fuel use. They include: type
of fossil fuel, crop type, soil type, tillage system, and type of rotation. Since diesel oil is the
predominant fuel, no further consideration of the type of fuel was made.
35. Although regular gasoline is used by farmers, its use for the farm business is very small, and therefore, not
included. Most crop production-related activities involve the use of machinery fuelled by diesel oil.
40
Canadian Economic and Emissions Model for Agriculture: Report 1
Methodology for the Estimation of Emission Coefficients
In order to maintain some consistency between inputs of fuel cost in CRAM and the ECs
(which are related to the level of use), an attempt was made to find a conversion factor for
fuel cost into physical quantity. For this effect, data on physical quantities of fuel used for
crop operations in Saskatchewan were obtained from Rutherford and Gimby (1988). These
data were available by three soil types, and for four crops: spring wheat, winter wheat,
coarse grains, and oilseeds. Regression analysis was used to determine the relationship
between quantity of fuel used and cost. Results are shown in Appendix C (Section C.1).
Results were very poor. The coefficient for fuel cost was not significantly different from zero,
suggesting there was no statistical basis for using these results for obtaining ECs. As a result,
this approach was abandoned.
An attempt was made to obtain this information from Statistics Canada (1983), and from the
Census of Agriculture (Statistics Canada, 1993). Both these sources were found to be deficient
for this study. The first source provided quantity of fuel used on a per farm basis and
reflected the 1981 situation. This did not reflect 1994 emission levels. The second source did
not provide any suitable information on the physical quantities of fuel used.
Attempts were made to obtain this information from other secondary sources, such as the
Canadian Agricultural Energy End-Use Data and Analysis Center. However, no suitable
data were found.
The approach used in this study to estimate the ECs included collection of data on quantity
used for various crops in different provinces. Farm budget data showing the quantity of fuel
used for the production of various crops were collected for the provinces of Saskatchewan,
Manitoba, Ontario, Nova Scotia, and Newfoundland. For Saskatchewan, this information
included details on conventional and no tillage systems for the three soil zones — Brown,
Dark Brown, and Black. Information for Nova Scotia and Newfoundland was very weak;
available data pertained to fewer crops, with much of the details not provided36. This
information was not used in this study. Data for the remaining regions are shown in
Appendix D.
The above information was used for various regions in the following manner: Saskatchewan
information was also used for British Columbia and Alberta, according to the appropriate
soil zone. Crop districts were classified according to the predominant soil type, or an average
of two soil types, if the situation warranted. Manitoba data were used for that province only.
Ontario data were used for all the Eastern Canadian provinces.
No budgets were available for potatoes, corn silage, hay, or other crops (stubble or on
summerfallow), or for pastures or unimproved pasture lands. For other crops, the following
rule was applied: other crops in Western Canada were assumed to be similar to wheat, and
in Eastern Canada, similar to corn. No satisfactory budget for potatoes was available for any
province. Fuel quantities were assumed to be double the quantity of fuel used in the
production of canola. Similarly, fuel quantities for pasture land were assumed to be double
those for barley. For the unimproved pastures, it was assumed that no fuel is required37.
36. Major deficiency in this data set was that details on quantities of inputs were not provided.
37. This was based on the cost information used for CRAM. The fuel costs for this enterprise was zero.
Canadian Economic and Emissions Model for Agriculture: Report 1
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Chapter 4
The quantity of fuel used per hectare was converted into an emission coefficient using the
relationship between use of liquid fuels and CO2 emissions. These coefficients are shown in
Table 4.4 (based on Smith, Rochette and Jaques 1995) and in Table 4.5 (based on Manaloor
and Yildirim, 1996). In order to use the conversion coefficient, it was assumed that one litre of
diesel contains 0.03868 GJ38 of energy.
Table 4.4: Level of Carbon Dioxide Released into the Atmosphere Related to Direct
Use of Fossil Fuels
Emissions in terms of kt CO2 per annum
per TJ of energy in the fuel
Fuel Type
Natural Gas
0.04967
Motor Gasoline
0.06799
Kerosene and Stove Oil
0.06744
Diesel Oil
0.07070
Light Fuel Oil
0.07311
Heavy Fuel Oil
0.07390
Source: Estimated from data presented in Smith et al. (1995), p. 20.
Table 4.5: Level of Carbon Released into the Atmosphere through Indirect Use of
Fossil Fuels in Agriculture
Emissions in terms of kg C per annum
per GJ of energy in the fuel
Fuel Type
Natural Gas
13.78
Liquid Fuels
22.29
Coal
24.65
Source: Data presented in Manaloor and Yildirim (1996), based on Marland and Turhollow (1990).
Indirect Fuel Use on Farms for Crop Production
Indirect fuel use includes use of electricity for operations directly related to crop production,
such as machine maintenance and crop drying. Unfortunately no reliable information is
available for this amount so used. For this reason, emissions from this source were not
estimated in this study.
4.1.1.4
Biomass Burning
Burning of biomass (crop residues) is a common practice in certain agricultural regions, and
for certain crops. It releases the carbon contained in organic matter into the atmosphere.
Factors that may affect its release include: type of crop, amount of biomass burnt, and
burning practices. Unfortunately, reliable information on these factors is not available.
Through personal communications, the Manitoba Crop Insurance suggested that somewhere
38. A GJ, giga joule, is one billion joules, where a joule is a measure of active energy in a product.
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Canadian Economic and Emissions Model for Agriculture: Report 1
Methodology for the Estimation of Emission Coefficients
between 10% and 40% of cereals are burnt. The consensus is that canola is hardly ever burnt.
However, the practice of burning flaxseed residues is more common and may extend to
80% - 95% of this crop’s area.
In light of the above, the following assumptions were made. All crops except canola, pasture,
unimproved pastures, and summerfallow were assumed to be burning some biomass. For
these crops, a proportion of 5% was used, whereas for flaxseed this proportion was assumed
to be 90%.
At this time, no reliable information is available for an emission coefficient from biomass
burning in Canada. Mehra and Damodaran (1993) estimated emissions of various gases into
the atmosphere from burning of biomass, which are shown in Table 4.6. However, the
appropriateness of these estimates for Canada can be questioned.
Table 4.6: Emission of Various Gases from Biomass Burning
Type of Gas Emitted
Rate of emission in tera grams (Tg)
per Tg of dry matter
Carbon dioxide
1.4865
Carbon monoxide
0.0946
Methane
0.0054
Nitrous oxide
0.00005
Source: Mehra and Damodaran (1993) p. 29.
In this study, estimation of EC was related to the production of biomass, and burning
practices. This required estimation of the dry matter weight of the biomass for various crops.
This was taken from estimates done under Section 4.1.1.1, Photosynthesis. The CO2 released
into the atmosphere was assumed to be totally related to the carbon content of the dry matter
weight as estimated for photosynthesis.
4.1.1.5 Use Of Manures
To provide additional nutrients to plants, farmers use some animal excretions/wastes
(manure) as fertilizer. The results is some leaching of the nutrients, and at the same time,
some oxidation, releasing CO2. Conceptually, direct emissions of manure application depend
on soil texture, method of application and quantity of manure. Soil texture is important in
determining leaching versus emission rates. Information is also needed on crops receiving
manure application, rate of application, type of manure (nutrient contents), and rate of
leaching of nutrients into the soil by soil type.
An overview of the different ways in which GHG emissions from livestock excretions/
wastes take place is shown in Figure 4.1. Livestock excretions/wastes can be applied as
manure in one of two ways: either direct from the farm animals themselves, such as those on
pasture lands; or by spreading manure on crop fields. Therefore, a separate emission
estimate was made for each method of application. It was further assumed that regional
differences occurred among emission coefficients on account of weather and leaching effects.
Ideally, one needs to develop a total gaseous budget starting with the production of animal
excretions/wastes, emissions during their handling, loss of animal excretions/wastes
between livestock enterprises and crop fields, and ECs for crop fields which explicitly take
Canadian Economic and Emissions Model for Agriculture: Report 1
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Chapter 4
into account leaching of nutrients. Attempts were made to obtain this information from the
Statistics Canada (1996b) survey. However, much of this information was found to be
descriptive and qualitative, and did not shed any light on the nature of manure handling and
application practices by farmers in various provinces.
Since appropriate information was not available, emissions through manure application
were tied to production of livestock excretions/wastes. Details on the methodology followed
for CO2 is shown in Section 4.2.1.2, for CH4 in Section 4.2.2.2., and for N2O in Section 4.2.3.1.
4.1.1.6 Use of Chemicals
In order to control pests and diseases, farmers apply chemicals — herbicides, fungicides, and
insecticides, to crops. Some of these contain carbon, and when applied, release that as CO2
into the atmosphere. Major factors affecting this type of emissions include: herbicide type,
crops treated, level of treatment by rotation and tillage, regional differences, as culminated
through soil and climatic factors.
Methodology for the estimation of these emissions was almost parallel to that for fuel. A
regression analysis was undertaken between the quantities of chemicals used on
Saskatchewan farms (as provided by Rutherford and Gimby 1988), and the CRAM costs. The
results, as shown in Appendix C (Section C.2), were very poor and this approach was
abandoned.
Emissions of CO2 from use of pesticides is dependent on the energy contents of the
chemicals. Manaloor and Yildirim (1996), based on work by Pimentel (1980), suggest an
emission of 20.7339 kg C per GJ of energy contained in the chemicals. However, estimates of
energy contents of various chemicals, along with the quantity of various chemicals are not
readily available.
In this study, EC for chemicals was estimated by multiplying the quantity of chemicals used
by their respective per unit emissions. The quantity that is needed in this context is one by
crops, regions, and tillage practices. Thus, this procedure was divided into two steps. Step
one included estimation of the quantities of chemicals as based on crop budgets presented in
Appendix D. In the second step, a carbon emission coefficient was derived from the carbon
content of the herbicides most commonly used, based on the chemical formula (Table 4.7).
The EC was based on the assumption that 70% of the carbon in a pesticide was mineralized
and emitted as CO2 per application.
44
Canadian Economic and Emissions Model for Agriculture: Report 1
Figure 4.1 Emissions of Greenhouse Gases from Livestock Excretions/Wastes and Manures
Chapter 4
45
Canadian Economic and Emissions Model for Agriculture: Report 1
46
C8H14N4OS
C17H29NO3S
C10H16NOCl3S
C13H16F3N3O4
Sencor
Poast
Avadex
Treflan
Source: Estimation
b
Hoegrass 284 and Torch
Puma and Torch
c
Glyphosphate and Banvel.
a
200.62
C9H903Cl
MCPA
335.28
304.70
327.50
214.30
390.11
169.07
Roundup
Rustler 2c
839.31
Laserb
C3H8NO5P
C12H16NO5Cl
Puma, excel
361.78
319.24
325.19
C12H12N3O4F3
C16H14O3Cl2
Hoegrass 284
221.04
Edge
C8H6O3Cl2
Banvel
221.04
602.10
C3H6O3Cl2
2,4-D amine
46.53
39.38
62.29
44.80
53.83
33.84
21.29
40.03
39.80
45.11
45.84
59.04
43.43
16.29
49.94
%
g
240.30
C
Mean
Weight
Hoegrass IIa
C10H12N2O3S
Formula
Basagran
Brand
545
400
184
500
400
192
356
237
92
1
310
284
480
700
253.58
157.53
114.61
223.99
215.33
64.97
75.70
94.68
36.62
0.30
142.10
167.68
208.47
114.01
239.70
g L-1
g L-1
480
C Content
Active
Ingredient
Table 4.7: Average Emissions of Carbon from Selected Herbicides
2.50
3.50
1.40
0.46
1.18
2.80
1.50
2.50
1.00
1.65
3.50
2.65
0.26
1.10
2.00
L ha-1
Mean
Application
Rate
633.95
551.36
160.46
103.59
253.02
181.91
113.70
236.69
36.62
0.50
497.36
444.35
54.20
125.41
479.40
gC ha-1
C per
Application
444
386
112
73
177
127
80
166
26
0
348
311
38
88
336
gC ha-1 yr-1
Emissions
Chapter 4
Canadian Economic and Emissions Model for Agriculture: Report 1
Methodology for the Estimation of Emission Coefficients
4.1.2 Nitrous Oxide
Eight agricultural activities were identified in Table 3.1, which are related to emissions of
N2O. Since emissions from manure, as discussed earlier, are accounted under livestock
production-induced emissions, they are excluded from this section. Of the remaining seven
crop production activities, three are related to the use of farm inputs (fossil fuels, fertilizer,
and chemicals), while the remaining through crop management practices. Two activities are
particularly relevant to the N2O emissions, crop residue, and production of nitrogen fixing
crops, such as legumes.
4.1.2.1 Loss of Soil Organic Matter
Organic matter is about 10% nitrogen, which can be oxidized into N2O through microbial
decomposition of organic matter, a process which is accelerated by tillage. Various factors
affect the amount of N2O emitted through loss of organic matter, but the following ones may
be considered important: crops, regions (as exemplified through soil type and climatic
variables), tillage practices, yield, and crop rotation.
The methodology for the estimation of ECs for N2O was almost identical to that followed for
the CO2, with the exception that the data on the loss of nitrogen were used instead of loss of
carbon. These data were also obtained from Smith, Rochette and Jaques (1995).39 A
coefficient of 1.5716 (ratio of the molecular weights of N2 : N2O) was used to convert nitrogen
into N2O. 40
4.1.2.2 Burning of Fossil Fuels
The burning of coal and natural gas releases N2O, according (Lashof and Tirpak 1989), as
does burning of oil. However, because of the lack of available data, as noted earlier, indirect
energy use was not included for crop production activities.
Using the results provided by Mehra and Damodaran (1993), it was estimated that the ratio
of CO2 emissions to those of N2O is 1:0.00008. In this study this coefficient was multiplied by
the CO2 emissions to generate a coefficient for N2O.
4.1.2.3 Biomass Burning
Burning the biomass releases nitrogen as N2O. Factors that determine the emission levels are:
crop type, amount of dry matter (as affected by tillage and rotations), and burning practices.
For estimating the EC, total dry matter produced by plants and proportion of area burnt
were taken from Section 4.1.1.4. The conversion coefficient for dry matter into N2O was
presented in Table 4.6. This coefficient was used to determine the emission coefficient for
N2O from biomass burning.
4.1.2.4 Crop Residues
In Canada, inevitably some crop residues are left in the field after harvest. These residues
contain some nitrogen, a part of which can become N2O. To estimate this emission,
information provided by Desjardins (Undated) was used. It was assumed that one kg of dry
biomass contains 0.015 kg of nitrogen. Of this nitrogen, 1.25% finds its way into the
39. These data were presented in Appendix B of Smith, Rochette and Jaques (1995) study.
40. For details see Desjardins (Undated).
Canadian Economic and Emissions Model for Agriculture: Report 1
47
Chapter 4
atmosphere as N2O. The amount of dry matter equivalent biomass has already been
estimated in the context of Biomass Burning. This amount was multiplied by a factor of
0.0002947 kg of N2O per kg of dry biomass.
4.1.2.5 Use of Fertilizers
Fertilizers are added to the soil to supplement nutrients needed by plants. Many fertilizers
contain nitrogen, a part of which is released into the atmosphere as N2O. The level of these
emissions depends on several factors such as: type of fertilizer, crops fertilized by region,
tillage, and rotations, rate of fertilization. The relationship between the application of
fertilizers and emissions of nitrous oxide is shown in Table 4.8.
Table 4.8: Levels of Emissions of Nitrous Oxide by Type of Fertilizer
Fertilizer Type
% of N evolved to
atmosphere as N2O
Median Value
Anhydrous Ammonia
1 to 5
1.63
Aqua Ammonia
1 to 5
1.63
Urea
0.05 to 0.50
0.11
Ammonium Nitrate
0.04 to 0.50
0.12
Ammonium Sulphate
0.04 to 0.50
0.12
Diammonium Phosphate
0.10
-
Nitrogen Solutions
0.05
-
Sodium Nitrate
0.05
-
Source: Eichner (1990).
In this study, the EC for N2O from fertilization was estimated by taking into account the
quantity used, by type of fertilizer. Since the quantity used is different for various crops and
tillage systems, a methodology similar to that followed for fuel (as well as chemicals) was
adopted. Results are shown in Appendix C (section C.3). Unlike the previous two regression
analyses, results suggested that the relationship between CRAM fertilizer cost and quantity
is statistically valid. However, in order to keep consistency among various ECs, the approach
to estimate quantities from CRAM cost data was not used.
The quantity of fertilizer used for various crops in various regions under different tillage
systems was obtained from the crop budgets noted under Section 4.1.1.3, Use of Fossil Fuels.
It was assumed that most fertilizers used were in the form of urea or some form of
ammonium nitrate (or sulphate). This resulted in a coefficient of 0.0017 kg of N2O per tonne
of fertilizer applied to a given crop.
4.1.2.6 Production of Nitrogen Fixing Crops
Nitrogen-fixing crops are able to convert atmospheric N into organic N though symbiotic
association with microorganisms. Desjardins (1997) has reported a nitrogen content of
0.03 kg N per kg of dry matter for nitrogen fixing crops. Further assuming that 1.25% of the
nitrogen is converted into N2O leads to an emission factor of 0.0005894 kg N2O per kg of dry
matter.
48
Canadian Economic and Emissions Model for Agriculture: Report 1
Methodology for the Estimation of Emission Coefficients
The nitrogen fixing crops in this study included: field peas, lentils, and tame pastures. The
dry matter equivalent biomass for these crops has previously been estimated under Biomass
Burning. These estimates were multiplied by the above factor to yield an EC.
4.1.2.7 Chemicals
Some chemicals may contain nitrogen. However, since the evidence for this is very poor,
estimation of an EC for chemicals was not included.
4.2
Greenhouse Gases Emission Coefficients for Livestock Production
Livestock operations contribute to all three GHG emissions through various sources listed in
Table 3.2. These emissions can be divided into two types: direct emissions, and, indirect
emissions. Direct emissions are by farm animals, and their excretions/wastes. Indirect
emissions include use of fossil fuels for production-related activities, such as feed
distribution, heating/cooling of buildings, among others. In this section, methodology
adopted for estimating EC for these sources of GHG emissions is described.
Description of the methodology in this section is divided into three parts, one for each GHG.
The relevant sources of emissions, whether direct or indirect, are included within the
discussion for each GHG.
4.2.1 Carbon Dioxide
Carbon dioxide is generated both directly and indirectly by livestock operations. Sources of
these emissions and methodology for estimating their respective emission coefficients are
presented in this section.
4.2.1.1 Farm Animals
As part of a biological cycle, animals exhale CO2. However, other than a single Canadian
study by Kinsmen et al. (1995), no estimation of this emission has been made. Kinsmen’s
study estimated total emissions of CO2 from a dairy barn at 381 litres per day per cow. No
other information about other livestock enterprises is available. Even in this study, the
estimation is only for the barn as a whole, and does not separate the contribution of farm
animals from that of animal excretions/wastes. Since this is the only available study for
Canada, it was used to estimate the direct CO2 emission coefficient for farm animals.
In order to apply the results of Kinsman et al. (1995, p. 2764) to this study, a ratio between
methane emissions per cow and carbon dioxide emissions per cow was estimated41. For dairy
cows, this led to a coefficient of 0.37523 tonnes of CO2 per head per annum. For other
animals, the coefficients were estimated using their equivalence in terms of amount of
volatile solids excreted. The procedure required estimation of total animal or poultry
excretions/wastes by type of livestock enterprises. These figures were obtained from Liu
(1995), and are shown in Table 4.9. This implicitly assumes that CO2 emissions are related to
body weight and feed intake, which can be accurately measured by the quantity of volatile
solids excreted. Furthermore, it should be noted that these figures are for both respiration as
well as animal excretions/wastes, and no attempt was made here to separate the two because
of lack of information.
41. This ratio was 29.82 g of CO2 per g of CH4.
Canadian Economic and Emissions Model for Agriculture: Report 1
49
Chapter 4
4.2.1.2 Livestock Excretions/Wastes
Another major source of CO2 emissions by livestock production is through production of
animal excretions/wastes. Details on this emission rate are very poor because a number of
factors. Emissions of GHGs from animal excretions/wastes can be determined by disposal
method used by producers. Animal excretions/wastes may be disposed in one of three ways:
direct application as plant nutrients by farm animals (such as on the pasture lands),
application by farmers as manure on crop fields, and/or disintegration by manure handling
systems. Under all these options, some carbon contained in the excretions/wastes is either
released as CO2, or is retained as part of the SOM. As noted above, this source of emissions
overlaps with those from crop production.
Table 4.9: Production of Animal and Poultry Excretions/Wastes by Type of
Animal/Poultry
Animal Type
Volatile Solid (VS) in kilo tonnes
per head per year
Dairy Cattle
2,260.5
Other Cattle
1,103.8
Pigs
140.3
Sheep
338.8
Lambs
338.8
Chicken
5.6
Hens
7.9
Turkeys
22.6
Source: Liu (1995), p. 11.
Carbon dioxide from livestock excretions/wastes was assumed to originate either from
manure stored in solid storage systems, or directly from pasture. It was assumed that most
carbon loss from liquid or anaerobic storage systems was in the form of CH4. The proportion
of excretions/wastes from each animal type stored in solid systems, from Desjardins and
Mathur (1997), was used to determine the carbon (C) contained in solid stockpiles, assuming
that excretions/wastes were 45% carbon (Table 4.10). It was assumed that 57% C in manure
was mineralized during the stockpile period (Kachanoski and Berry, 1997). Further losses,
estimated to be 60% of the remaining C per year, occur when the stockpiled
excretions/wastes are spread in the field. Mineralization of 60% per year was based on the
assumption that 40% C added in the current year would be mineralized, plus an additional
20% loss from manure added in previous years. The total amount of CO2 (in kilograms per
head per year — kg hd-1 y-1) mineralized from manure in solid stockpiles is:
Total C mineralized (kg hd-1 y-1) + C mineralized in pasture (kg hd-1 y-1) *44/12
50
(4.2)
Canadian Economic and Emissions Model for Agriculture: Report 1
Methodology for the Estimation of Emission Coefficients
Table 4.10: Carbon Emissions from Animal Excretions/Wastes in Solid Storage.
Animal Type
Dairy cow
Volatile
Solids kg
head-1 yr -1
Mineralized C
kg yr -1
Solid Storage
%
kg
C head-1yr -1
Stockpile
Field
Total C
Mineralized
kg head-1 yr -1
1,898
47
401
229
104
332
Non-dairy cow
762
15
51
29
13
43
Swine
465
24
50
29
13
42
4
90
2
1
1
1
369
12
20
11
5
17
Poultry
Sheep
Source: Compiled using data from Kachanoski and Berry (1997).
A similar methodology was adopted for the emissions from animal excretions/wastes for
pasture animals. Results for these emission coefficients are shown in Table 4.11.
4.2.1.3 Contributions through Livestock Management
Carbon dioxide emissions from livestock management-related activities can be broadly
classified into two types: from direct use of fossil fuels and from indirect use of fossil fuels,
such as through use of electricity. Each of these requires a different method of estimation.
Table 4.11: Carbon Emissions from Animal Excretions/Wastes in Pasture
Animal Type
Dairy cow
VS*
(kg head-1 yr -1)
C Content of Manure in Pasture
kg head-1 yr -1
%
C Mineralized
kg head-1 yr -1
1,898.00
0
0
0
Non-dairy cow
762.00
84.00
640.00
384.00
Swine
465.00
0
0
0
4.00
1.00
0.04
0.02
369.00
88.00
325.00
195.00
Poultry
Sheep
* Volatile Solids
Source: Desjardins and Mathur (1997).
Emissions from the direct use of fossil fuels are associated with the use of mechanical devices
in livestock operations, such as feed distribution systems, manure handling systems, and
milking equipment. In addition, some buildings are heated by natural gas. Indirect use of
fossil fuels includes use of electrically powered devices, such as milking machines, heaters,
fans, and some use to livestock housing.
Factors that affect these emission levels include: types of livestock requiring management
operations, type of management operations, and type of fuel used. All these factors would
also have a regional dimension; in other words, all regions of Canada could not be assumed
to be homogenous in this respect. Estimation of the ECs was done separately for direct and
indirect energy uses.
Canadian Economic and Emissions Model for Agriculture: Report 1
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Chapter 4
Direct Use of Fossil Fuels
Information related to the use of various types of energy inputs for livestock management
operations in different regions of Canada is relatively poor. As a first step, data on the
expenditures on heating fuels purchased by various types of livestock farms were obtained
from Statistics Canada (1996a) for the year 1994. Details on this information are provided in
Table 4.12. According to these estimates, all livestock farms purchase some heating fuel.
However, since most cattle farms do not provide buildings or other shelters for cattle, it was
assumed that this expenditure is equal to zero. Other values were taken at face value.
The second step in the estimation of the EC was to calculate the coefficient on the basis of per
dollar of expenditures on heating fuels. For this purpose, data from Statistics Canada (1983)
were obtained. According to these data, three types of fuels are used as heating fuels for
business purposes: liquid petroleum gas, heating oil, and natural gas. The total amount of
these fuels used on Canadian farms was estimated by multiplying the total amount by the
proportion of that fuel used to heat building.
For liquid petroleum gas and heating oil, it was assumed that these have emissions similar to
those of diesel oil. Thus, for these fuels, an EC of 0.003159 tonnes of C per litre was applied.
For natural gas, an EC of 0.01378 tonnes of C per GJ was used. The total emission of CO2 was
obtained by multiplying the quantity used by the EC. Total emissions were divided by the
expenditures in 1981 and converted into 1994 prices42. This yielded an EC of 0.0101094 tonnes
of C per dollar of expenditures on heating fuels. This coefficient was multiplied by the
expenditures on heating fuels by dairy and hog farms, as shown in Table 4.12.
Table 4.12: Use of Heating Fuel by Type of Livestock Farm, 1994
Type of Livestock Farm
Expenditures on Heating Fuels $ per Head
Dairy
5.373
Cattle
3.230
Hogs
1.660
Poultry
0.668
Source: Estimated from data in Statistics Canada (1996b).
For poultry farms, this methodology yielded large levels of emissions, and therefore, it was
abandoned. Instead data on the use of heating fuels was obtained from Ostrander (1980).
Three types of fuels were used for heating: propane, fuel oil, and natural gas. Assuming that
the make-up of the total energy used in Canada is identical to that in the U.S., ECs per bird
were estimated. In order to differentiate these emissions from the indirect fossil-fuel based
emissions, these are shown under “Section 4.1.2.2, Burning of Fossil Fuels”.
Indirect Use of Fossil Fuels
Indirect use of fossil fuels is through the use of electricity for livestock management
activities. The starting point in this estimation was a collection of data on expenditures on
electric power by various types of livestock operations. Two sources of data were consulted:
Statistics Canada (1996b), and Pimentel (1980). The latter source provided articles by Cook,
42. For this purpose, farm input price index for petroleum products for Canada was used.
52
Canadian Economic and Emissions Model for Agriculture: Report 1
Methodology for the Estimation of Emission Coefficients
Combs and Ward (1980) for beef production, Oltenacu and Allen (1980) for dairy production,
Ostrander (1980) for poultry production, and Reid et al. (1980) for hog production systems.
Details on this information are shown in Table 4.13.
Table 4.13: Estimates of Expenditures and Quantity of Electric Power by Type of
Livestock Farms, Canada and U.S.
Type of Farm
Expenditures
in $ head-1*
kWh head-1
(1994)**
U.S.
KWh head-1
(1980)***
Canada
Dairy
43.09
718
437
Cattle
9.12
152
93
Hogs
5.52
92
28
0.61#
10.3#
0.169
Poultry: Broilers
Turkeys
0.510
Hens and Chickens
2.843
# All poultry.
Sources: *Statistics Canada (1996b).
**Estimated from Column (2) using a price of $0.06 per KWh.
***Pimentel (1980).
As can be seen from Table 4.13, the Canadian expenditures were significantly higher than
those estimated for the U.S. Two plausible explanations are: Canadian expenditures are gross
values (including farm overhead use of electrical power); and/or overestimated values of
price of electrical power used for computing the quantity. For these reasons, coefficients
suggested in the last column of this table were used.
Next was the identification of those sources of electrical power that lead to CO2 emissions.
Data were collected for each of the provinces on the source of electrical power generation, as
shown in Table 4.14. British Columbia, Manitoba, Quebec, and Newfoundland produce most
of their power through hydroelectric sources. In this study, it was assumed that hydroelectric
power, and other sources of electrical power (mainly nuclear power), do not yield any
emissions; steam power generation involves exclusively the use of coal; and internal
combustion power generation is through the burning of natural gas.
Under these assumptions, the quantity of electrical power used by livestock farms was
divided into two categories: generated by coal, and generated by natural gas. For both, an
emission coefficient of 0.000874 tonnes of CO2 kW-1 h-1 was used.
Canadian Economic and Emissions Model for Agriculture: Report 1
53
Chapter 4
Table 4.14: Distribution of Source of Electric Power Generation (Percent of Total) by
Province, 1994
Province
Steam
Internal
Combustion
Hydro
Other
Total
British Columbia
12.5
0.1
85.9
1.5
100.0
Alberta
90.6
0.1
4.2
5.0
100.0
Saskatchewan
74.1
0.0
25.2
0.7
100.0
0.6
0.1
99.3
0.0
100.0
Ontario
12.9
0.0
26.0
61.1
100.0
Quebec
0.1
0.1
96.8
2.9
100.0
New Brunswick
66.5
0.0
21.0
12.5
100.0
Prince Edward Island
83.2
0.0
0.0
16.8
100.0
Nova Scotia
90.3
0.0
9.6
0.1
100.0
4.1
0.2
95.7
0.0
100.0
Manitoba
Newfoundland
Source: Statistics Canada (1997).
4.2.2 Methane
For methane emissions, two sources, direct by livestock, and through animal
excretions/wastes, were identified (Table 3.2). Coefficients for both sources were estimated,
and the methodology is reported in this section.
4.2.2.1 Farm Animals
Different types of ruminant animals produce different levels of methane, according to the
level of feed intake, and their body weight. These emissions levels have been estimated for
different parts of the world, as well as for Canada. Crutzen, Aselmann, and Seiler (1988)
reported such estimates for broad categories of animals, which are shown in the middle
column of Table 4.15. The most significant source of this gas is cattle (ruminants), which
produce 55 kg of methane annually per animal. Sheep and goats also generate some
methane, approximately 5-8 kg of methane per animal per annum. These estimates have two
major limitations. They are somewhat outdated; and, furthermore, since they represent a
global average, they may or may not apply fully to Canada. Various Canadian studies were,
therefore, consulted and these estimates are shown in the last column of Table 4.15. These
coefficients were used in this study. Total methane emissions from farm animals were
estimated by multiplying the EC per head by the number of animals on farms by the type of
animals.
54
Canadian Economic and Emissions Model for Agriculture: Report 1
Methodology for the Estimation of Emission Coefficients
Table 4.15: Methane Emission Rates from Farm Animals
Type of Animal
Methane Emission
(kilograms per head per year)@
Cattle
Estimated Coefficient (kilograms
per head per year)
55
Beef cow
65*
Bull
75*
Feeder Calves
8*
Beef Yearling
52**
Stocker Calves
21*
Feedlot Cattle
15*
Dairy Cows
140
Dairy Yearlings
62**
Dairy Calves
29**
Pigs
1-1.5
Sows
3.3**
Pigs 20-60 lbs
1.4**
Poultry
0.0045***
Sheep
5-8
Goats
5
Horses
18
Mules/Asses
10
Sources: @Crutzen, Aselmann, and Seiler (1988)
*McAllister (1997)
**Mathur (Undated)
***Desjardins (Undated)
Table 4.16: Methane Emission Rates from Livestock Excretions/Wastes
Animal Type
Methane emission rate
kg of methane per kg of VS*
Dairy cow
0.019
Non-dairy cow
0.011
Swine
0.043
Poultry
0.024
Sheep
0.019
*Volatile Solids.
Source: Desjardins and Mathur (1997).
Canadian Economic and Emissions Model for Agriculture: Report 1
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Chapter 4
4.2.2.2 Contribution through Livestock Excretions/Wastes
In addition to CO2 emissions, part of the carbon contained in the animal waste is converted
into methane. The amount of such emissions varies by type of animal, since these are also
affected by the animals excretion rates and methane production potential, which, in turn, is
affected by feed intake, and climatic effect. For Canadian climatic conditions, Desjardins and
Mathur (1997) provided the estimates, as shown in Table 4.16. The amount of volatile solids
associated with animal excretions/waste by type of animal is given in Table 4.9. The EC for
CH4 from animal excretions/wastes was estimated as follows:
E C L M.WST
=
Q N TY LWST * MEVS
(4.3)
where
ECLM.WST
= emission coefficient from livestock waste (kilograms of
methane per animal per year)
QNTYLWST
= quantity of waste as volatile solids (kilograms of methane
per animal per year)
MEVS
= methane emissions (kilograms of methane per animal per
year)
Total emissions were a product of the EC and the number of animals by type of animal.
Estimates were made for each province and aggregated for Canadian emissions.
4.2.3 Nitrous Oxide
The two livestock production activities that are linked to emissions of N2O are: production of
animal excretions/wastes and use of fossil fuels indirectly through the use of electricity for
livestock management activities.
4.2.3.1 Livestock Excretions/Wastes
The contribution of emission of N2O from animal excretions/wastes is based on estimates by
Monteverde, Desjardins and Pattey (1997). Nitrous oxide emissions were estimated from
three sources of animal excretions/wastes: grazing animals on pasture (Table 4.17), stored
manure (Table 4.18), and, stored manure after its application to soils in the field (Table 4.19).
Emissions from all sources are based on the amount of nitrogen produced in waste by each
animal type, taken from Monteverde, Desjardins and Pattey (1997) and shown in Table 4.17.
Emissions from grazing animals were determined for non-dairy cattle, poultry and sheep,
based on the proportion of their excretion/waste production that occurs over a year in
pasture (Table 4.17). The emission coefficient (0.02) is from Monteverde, Desjardins and
Pattey (1997).
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Canadian Economic and Emissions Model for Agriculture: Report 1
Methodology for the Estimation of Emission Coefficients
Table 4.17: Nitrous Oxide Emissions from Grazing Animal Excretions / Wastes
Nitrogen Excretion
kg of Nitrogen per
animal per year
Animal Type
Amount in Pasture
%
Grazing Emission
EFG kg of Nitrogen
per animal per year
Dairy cow
63.0
0
0
Non-dairy cow
39.0
84.0
0.65520
Swine
14.0
0
0
Poultry
0.6
1.0
0.00012
Sheep
6.0
88.0
0.10560
Source: Monteverde, Desjardins and Pattey (1997).
Nitrous oxide emissions from storage systems (Table 4.18) was based on the proportion of
manure from each animal type held in one of four types of storage (AL - anaerobic lagoons,
LS - liquid storage, SSD - solid storage, and OS - other). The EC for each type of storage
system is from Monteverde, Desjardins and Pattey (1997).
Table 4.18: Nitrous Oxide Emissions from Stored Animal Excretions/Wastes
Manure in each storage system (%)1
Animal Type
AL
LS
SSD
10
23
23
7
0.52
0
1
14
1
0.112
Swine
25
50
18
6
0.065
Poultry
5
4
0
90
0.0028
Sheep
0
0
2
10
0.0054
Dairy cow
Non-dairy cow
OS
Storage Emission
EFS kg of Nitrogen
per animal per year
1
AL - Anaerobic lagoon, emission coefficient = 0.001;
LS - Liquid storage, emission coefficient = 0.001;
SSD - Solid storage, emission coefficient = 0.02;
OS - Other, emission coefficient = 0.005.
Source: Monteverde, Desjardins and Pattey (1997).
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Chapter 4
Table 4.19: Nitrous Oxide Emissions from Stored Animal Excretions/Wastes Applied
in the Field
Proportion of stored
manure applied to field
%
Animal Type
Dairy cow
Emission coefficient
Field emission EFF
kg N animal-1 yr-1
100
0.0125
0.788
16
0.0125
0.078
Swine
100
0.0125
0.175
Poultry
99
0.0125
0.007
Sheep
12
0.0125
0.009
Non-dairy cow
Source: Monteverde, Desjardins and Pattey (1997).
It was assumed that nitrogen remaining in manure after storage continued to be released as
N2O after being spread in the field (Table 4.19). It was further assumed that all stored manure
was eventually field applied. The field EC was estimated as follows::
EFF = (kg N animal-1 yr-1 * proportion applied* EF) * 0.2
(4.4)
where
EFF
=
field emission coefficient
kg N animal-1 yr -1
=
amount of N produced animal-1 animal type-1 yr -1
Proportion applied
=
% of total produced applied to field
EF
=
0.0125 (Monteverde et al.,1997)
The factor 0.2 was derived using Monteverde et al. (1997) as:
kg NH3 + NOx - N per kg N excreted
(4.5)
The total nitrous oxide emission coefficient was determined as follows:
ECN.WST = EFG + EFS + EFF * 44/28
(4.6)
where
ECN.WST
= total nitrous oxide emission (kg N2O animal-1 yr -1)
EFG
= nitrous oxide emissions from grazing animals (kg N animal-1 yr -1)
EFS
= nitrous oxide emissions from stored manure (kg N animal-1 yr -1)
EFF
= nitrous oxide emissions from field applied manure (kg N animal-1 yr -1)
44/28
= conversion factor for N to N2O
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Methodology for the Estimation of Emission Coefficients
4.2.3.2 Livestock Management Activities
The energy inputs used directly for livestock management activities do not contain any
nitrogen, and therefore, there are no direct emissions of N2O from that source. The indirect
energy inputs, use of electricity, and through that use of coal and natural gas, contain a small
part of nitrogen. These emissions are estimated in this section.
As noted earlier (Section 4.2.1.3), two types of electricity (steam generated, and internal
combustion based) are associated with emissions of GHGs. The quantity of coal and natural
gas required to produce this electric power has already been estimated in Section 4.2.1.3. The
only additional information required now is the emission level of N2O from the use of coal
and natural gas. These emissions were estimated using the relative ratio of CO2 and N2O
emissions (1:0.00008, as reported in Section 4.1.2.2).
The above noted methodology for the GHGE sub-model (containing crop and livestock
production modules) was used to estimate various ECs for the three GHG emission
activities, production activities, and production regions. The results of total emissions for the
three GHGs are presented in the next chapter.
Canadian Economic and Emissions Model for Agriculture: Report 1
59
Chapter 5: Results for the Base
Scenario
Emission coefficients, as estimated using the methodology reported in the previous chapter,
were multiplied by the base scenario results from CRAM for the area under various crops
and by the size of the livestock enterprises. Section 5.1 describes agricultural production in
Canada, and various provinces, as estimated by CRAM. Both crop and livestock production
are included in this discussion. The estimated levels of GHG emissions are presented for the
above set of agricultural production patterns in the rest of the chapter. The sink function
provided by crops is discussed in Section 5.2. The next two sections (5.3 and 5.4) deal with
the emission of GHGs (sources). Results are presented in terms of emissions by enterprises,
by regions, and by GHG emission activities. These results are also compared in this chapter,
to those in other Canadian studies. A regional distribution of GHG emissions is presented in
the last section.
5.1 Agricultural Activity in the Base Year (1994)
Agricultural activity in CRAM is estimated both in terms of physical indicators, area and
production, as well as in terms of economic indicators — value of sales, producer surplus,
and government expenditures, among others. Since the GHG emission levels were
hypothesized to be related to the physical indicators, economic indicators are not presented
in this chapter.
Let us start with the overall land use in Canada. The area under major land uses, as estimated
by the model is listed in Table 5.1. In 1994, there were a total of 62.2 million hectares of
agricultural lands43. Of this land, 7.2 million hectares is in Eastern Canada, with the
remaining 55 million hectares in the three Prairie provinces and British Columbia. In terms of
use of this land, 57% of the total is cropped area. This area includes summerfallowing, since it
is a part of the major rotations followed in the Prairies. The remaining 43% of the total lands
is under forage, either producing hay or as pastures (improved or unimproved).
43. The land area shown here is arable, and excludes uncultivated area.
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Chapter 5
Table 5.1: Land Use in Canada, 1994
Area in Thousand Hectares
Particulars
Eastern Canada
Western Canada
3,184
25,196
28,380
45.6
0
6,828
6,828
11.0
2,170
4,743
6,913
11.1
Area under Improved
Pastures
741
3,400
4,141
6.3
Area under
Unimproved Pastures
1,110
14,853
15,963
25.7
Total Area
7,205
55,020
62,225
100.0
Area under Crops*
Summerfallow Area
Area under Hay
Canada
% of Total for
Canadian Area
*Excluding area under summerfallow
Source: C.E.E.M.A. output.
With the exception of summerfallowing, the proportion of each land use type is not different
between Eastern and Western Canada. In Eastern Canada, hay lands constitute some 30% of
the total agricultural land base, as compared to only 9% for the Western Canada.
The nature of crops grown in the two regions is shown in Table 5.2. It illustrates significant
difference between the two regions. In Eastern Canada, soybeans, and corn (for grain) are the
major crops. In contrast, in Western Canada, wheat and canola make up over half the total
area.
Another major difference in the nature of crop production in the two regions is the tillage
system. In the three Prairie provinces, farmers have started to substitute conventional (or
intensive) tillage systems by systems that require less tillage, but more cash inputs (notably
fertilizer and chemicals). During 1994, according to CRAM, conventional tillage systems
were practised on about two thirds of the total cropped area,44 as shown in Table 5.3.
The other major component of agriculture industry in Canada is livestock production. As
noted earlier, only four types of livestock enterprises were included in this study. These
were: beef cattle, hogs, dairy, and poultry. The number of livestock and poultry is shown in
Table 5.4, as are details on types of livestock inventory on farms. For example, there were
10.6 million beef cattle in various parts of Canada during 1994, of which almost 4 million
head were beef cows.
Details on the nature of agricultural production activities as presented here will assist the
reader in appreciating the results of emission levels of various greenhouse gases in Canada
and its regions. This is because, as noted earlier, all emissions were linked to various
activities related to GHG production.
44. One should note that the proportion of area under different tillage systems was based on the 1991 Census of
Agriculture. The 1996 Census of Agriculture (see Statistics Canada, 1993) reports significantly higher
proportion of the total area under minimum- and zero-tillage systems.
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Table 5.2: Area Cropped In Canada by Type of Crops, 1994
Area in Thousand Hectares
Crops
Eastern Canada
Western Canada
Canada
% of Total Area
in Canada
Wheat
365
8,281
8,645
30.5
Durum
0
2,346
2,346
8.3
703
1,762
2,465
8.7
Malt Barley
0
2,558
2,558
9.0
Oats
0
1,675
1,675
5.9
Canola
0
5,775
5,775
20.3
Flaxseed
0
732
732
2.6
Corn for Grain
933
0
933
3.3
Corn for Silage
143
8
151
0.5
Lentils
0
399
399
1.4
Field Peas
0
696
696
2.5
Potatoes
91
35
126
0.4
Soybeans
820
0
820
2.9
Other Crops
129
938
1,067
3.7
3,184
25,196
28,380
100.0
Barley for Feed
Total
Source: C.E.E.M.A. output.
Table 5.3: Distribution of Cropped Area in the Prairies by Tillage Systems, 1994
Tillage Systems
Intensive (Conventional) Tillage
Area in Thousand
Hectares
% of Total Area
17,479
69.4
Moderate (Minimum) Tillage
6,461
25.6
No (Zero) Tillage
1,256
5.0
25,196
100.0
Total
Source: C.E.E.M.A. output.
As noted above, crop production can lead to both emissions (source) as well as sequestration
(sink) of CO2. Each is presented separately.
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Chapter 5
5.2 Accounting Framework for Agricultural Emissions
Although conceptually, various agricultural activities discussed in Chapters 3 and 4 are
related to agricultural production activities, some are anthropogenic, while others are a part
of the natural cycle (such as the carbon cycle). The latter includes three sources:
photosynthesis, biomass burning, and CO2 emissions from the livestock excretions/wastes. It
should also be noted that for some sources, such as N2O emissions from SOM, available data
Table 5.4: Livestock Inventories on Farms in Canada, by Type, 1994
Livestock Type
Number
Beef Cattle (Thousand Head)
Cow-Calf
3,980
Replacement Animals
942
Stocker Calves
2,318
Feeder Calves
2,018
Feeder Yearlings
1,122
Bulls
218
Sub-total
10,598
Hogs (Thousand Head per Period)
Sows
1,101
Growers
7,935
Sub-total
9,036
Dairy Cattle (Thousand Head)
Dairy Cows
1,273
Dairy Heifers
406
Dairy Heifer Calves
594
Veal Calves
421
Sub-Total
2,694
Poultry (Thousands of birds)
Broilers
290,869
Layers
15,247
Turkeys
12,857
Sub-Total
318,973
Source: C.E.E.M.A. output.
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Canadian Economic and Emissions Model for Agriculture: Report 1
Results for the Base Scenario
and information has not yielded reliable estimates45. For this reason, these emissions were
excluded from the total GHG emissions from agricultural activities.
Estimated levels of emissions related to these activities are shown in Table 5.5. Results are
presented in terms of actual quantity of each gas, as well as in terms of its effect on global
warming. The latter is called “CO2-equivalent” emissions. As noted in Chapter 1, CO2
equivalence for methane was 21, while that for nitrous oxide was 310.
Table 5.5: Emissions of Greenhouse Gases Not Included in this Study, 1994
Activity
Gas
Level of Emissions in
kt yr-1
CO2-equivalent
Photosynthesis
CO2
-361,238*
-361,238*
Biomass Burning
CO2
6,656
6,656
Livestock Waste
CO2
13,621
13,621
SOM Loss
N2O
535
165,923
* A negative sign on the emissions indicates a sink of greenhouse gas.
Source: C.E.E.M.A. output.
Let us start with the emissions not included in the agriculturally-induced total GHG
emissions. Results are shown in Table 5.5. Photosynthesis absorbs a total of 361,238 kt of
atmospheric CO2, and thus, constitutes the largest sink (among agriculturally related
activities). The other activities included under the carbon cycle are relatively smaller
contributors. Biomass burning generates only 6,656 kt of CO2, while livestock excretions/
waste generates another 13,621 kt. Although in absolute quantity, the emissions of N2O are
very small (about 535 kt), when this value is converted into CO2-equivalent level, emission
levels increase to almost 165,923 kt. As noted earlier, because of relatively lower level of
confidence in the last set of data, these emissions were excluded.
One should be careful in interpreting these quantities. The sink function of agricultural
production as stated here is in terms of gross levels, and represents the carbon cycle only
partially. Since the scope of source function activities included in this study is narrow (i.e.,
limited to farm level production-related activities), these estimates might give a somewhat
biased estimate of the net contributions of agriculture. Although plant photosynthesis results
in the sequestration of CO2 in the plant biomass, the products so produced subsequently
become a source of GHG emissions. Some of these sources are included in the present
analysis, while others are not. For example, the cereal grains and oilseeds are either exported
or consumed locally. The exported products are typically destined for use by either people or
farm animals. Both people as well as animals (in the importing countries) are a source of
some GHG emissions, which are not included in the above accounting of the sink function.
For this reason, these estimates may be somewhat overestimated.
45. Using the CENTURY model, Smith (1995) provided a rate of these emissions, but the level of confidence in
these results is rather poor.
Canadian Economic and Emissions Model for Agriculture: Report 1
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Chapter 5
5.3 Agricultural Activities as a Source of Greenhouse Gas Emissions
In addition to photosynthesis, eight crop production-related activities and three livestock
production-related were identified as possible sources of emissions of various greenhouse
gases46. The results of the levels of emissions in Canada are presented in this section. The
measurement of emission levels can be carried out at two levels: either at the individual gas
level or at the CO2-equivalent level, which reflects the global warming potential of various
GHGs.
5.3.1 Estimated Total Emission Levels
In 1994, total GHG emissions (in CO2-equivalent basis) were estimated to be 62,501 kt per
year. This level is based on the 1994 production levels and agricultural practices as portrayed
in CRAM. As shown in Table 5.6, crop production activities contribute almost 48% of this
total. Among various gases, CO2 emissions are only 30.8% of the total emissions. The largest
contributor to total emissions of GHGs in Canada is methane, which constitutes roughly 47%
of the total, in terms of its CO2-equivalent emissions.
Table 5.6: Total Greenhouse Gas Emissions, CO2-equivalent, by Gas, kilo tonnes per
year, 1994
Greenhouse Gas
Carbon dioxide
Crop
Production
Livestock
Production
Total
Agricultural
Activities
% of the Total
17,864
1,407
19,271
30.8
0
29,152
29,152
46.6
Nitrous Oxide
12,353
1,726
14,079
22.6
Total
30,217
32,285
62,501
100.0
48.4
51.7
100.0
Methane
% of the Total
Source: C.E.E.M.A. output.
5.3.2 Distribution of Total Emissions by Activity
Distribution of total emissions by specific agricultural activities that are linked to GHG
emissions is shown in Table 5.7. When the global warming potential of each gas is taken into
account, animal excretions/wastes contribute the most. This source is estimated to have
emitted 35% of the total agriculturally-induced emissions of greenhouse gases in Canada.
The loss of SOM, thereby releasing CO2 into the atmosphere, seems to the second highest
contributor. Some 10,631 kt of GHGs are emitted by this source, which constitute 17% of the
total CO2-equivalent emissions in Canada.
Also, from crop production, CO2 appears to be the major gas being emitted, while methane
dominates emissions from livestock production. The major livestock activities producing
methane include the ruminant process of farm animals and their excretions/wastes, both of
which are large producers of methane.
46. These activities are listed in Table 3.1 of this study.
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Canadian Economic and Emissions Model for Agriculture: Report 1
Results for the Base Scenario
Table 5.7: Total Greenhouse Gas Emissions, CO2-equivalent, by Gas and GHG
Emission Activity, Crop and Livestock Production, kilo tonnes per year,
1994
Activity
CO2
CH4
N2O
Total
CROP PRODUCTION
Biomass Burning
0
0
114.2
114.2
Crop Residue
0
0
7,495.1
7,495.1
Fertilizer
0
0
2,234.1
2,234.1
Manure
0
0
1,110.4
1,110.4
Fossil Fuel
7,159.4
0
195.1
7,354.5
Chemicals
73.8
0
0
73.8
0
0
1,203.7
1,203.7
Soil Organic Matter
10,630.7
0
0
10,630.7
Sub-Total
17,863.9
0
12,352.7
30,216.6
0
9,263.1
0
9,263.1
1,407.1
0
0
1,407.1
0
19,888.7
1,725.9
21,614.6
1,407.1
29,151.8
1,725.9
32,284.8
19,271.0
29,151.8
14,078.6
62,501.4
Nitrogen Fixing Crops
LIVESTOCK PRODUCTION
Raising Livestock
Livestock Management
Animal Waste
Livestock Total
Grand total
Source: C.E.E.M.A. output.
5.3.3 Distribution by Regions
Distribution of CO2-equivalent emissions by various provinces is shown in Table 5.8.
According to these estimates, Western Canadian agricultural production contributes
significantly higher levels of emissions than Eastern Canadian agriculture. For all
agricultural activities, Eastern Canadian agriculture contributes 36.9% of the total
agriculturally-induced emissions of greenhouse gases in Canada.
In terms of all gases, Alberta and Saskatchewan top the list in crop production, and Alberta,
Ontario, and Quebec in livestock production. For crop production-related emissions, 87% of
the total emissions are generated in Western Canada, but only 44% for livestock production.
Canadian Economic and Emissions Model for Agriculture: Report 1
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Chapter 5
Table 5.8: Total Greenhouse Gas Emissions, CO2-equivalent, by Gas and Province, kilo
tonnes per year, 1994
Province
CO2
CH4
N2O
Total
CROP PRODUCTION
British Columbia
335.1
0
449.2
784.3
Alberta
7,231.9
0
3,403.3
10,635.3
Saskatchewan
5,738.9
0
4,268.4
10,007.3
Manitoba
3,298.6
0
1,577.0
4,875.6
Ontario
722.4
0
1,565.0
2,287.4
Quebec
486.1
0
885
1371
New Brunswick
-22.6
0
68.6
46.0
Prince Edward Island
81.3
0
47.2
128.5
Nova Scotia
-7.3
0
71.8
64.6
Newfoundland
-0.6
0
17.2
16.6
17,863.9
0
12,352.7
30,216.6
37.3
1,044.6
80.2
1,162.1
Alberta
331.0
5,320.0
374.4
6,025.3
Saskatchewan
142.7
2,603.6
192.2
2,938.5
Manitoba
147.4
3,697.2
180.9
4,025.5
Ontario
345.3
7,655.7
423.0
8,423.9
Quebec
342.6
7,854.1
417.8
8,614.6
New Brunswick
15.4
261.1
16.5
293.0
Prince Edward Island
18.5
284.4
16.1
319.0
Nova Scotia
24.6
381.3
21.9
427.8
2.2
49.9
3.0
55.1
1,407.1
29,151.8
1,725.9
32,284.8
19,271.0
29,151.8
14,078.6
62,501.4
Total Crops
LIVESTOCK PRODUCTION
British Columbia
Newfoundland
Total Livestock
Grand Total
Source: C.E.E.M.A. output.
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Canadian Economic and Emissions Model for Agriculture: Report 1
Results for the Base Scenario
5.4 Total Emissions of (Non-CO2-equivalent)
The estimated GHG fluxes for each of the three GHGs are presented in this section (in actual
quantities, as opposed to in terms of their global warming potential, as estimated in terms of
CO2-equivalence). The estimates of this study are compared with recent Canadian studies.
The results are shown in Table 5.9 for CO2, Table 5.10 for CH4, and in Table 5.11 for N2O.
5.4.1 Carbon Dioxide
Since the equivalence factor for the CO2 is equal to one, these results are identical to those
presented above. For this gas, major sources of emissions include loss of soil organic carbon
(released through tillage systems used, plus microbial activities), and burning of fossil fuels
(see Table 5.9). Other sources, such as the use of chemicals, also contributed, but only to a
minor extent, to total emissions. One should note that the fossil fuel use in this study was
limited to that used directly for crop production activities, and did not include any indirect
(overhead) farm business-related operations.
5.4.2 Methane
For emissions of methane from agricultural activities, crop production was estimated to
make no contribution. This is because of the methodology selected for this study, where all
livestock excretions/wastes, whether applied to the crops as manure or not, were allocated
to emissions from livestock operations. The total methane emission level was estimated to be
1,390 kt (Table 5.10). Among the major livestock production activities, farm animals
produced almost two thirds of the total methane emissions.
5.4.3 Nitrous Oxide
In absolute quantities, emissions of N2O are the smallest among the three gases. Its annual
level of emissions from agricultural activities is estimated to be 45 kt, most of which (88%) is
from crop production activities (Table 5.11). Loss of SOM is the major source of this emission.
5.4.4 Comparison of Results with Other Studies
In Tables 5.9 to 5.11, a comparison of estimates of this study is made with those of recent
Canadian studies. Before making this comparison, some caveats should be noted:
•
Studies have a different scope of estimation; therefore total emissions are not
exactly comparable.
•
The scope of agricultural activities included in this study is slightly different from
other studies; in this study it is defined by the specification of CRAM.
•
The scale of agricultural activities (such as number of livestock on farms, or farm
inputs used in the production process) may also be slightly different.
Canadian Economic and Emissions Model for Agriculture: Report 1
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Chapter 5
Table 5.9: Estimated Carbon Dioxide Emissions for Agricultural Production Activities,
and Comparison with Other Study Estimates, 1994
No.
Description
1
Photosynthesis
2
Soil Organic Matter
3
Estimated
Other Estimates
Amount in kt yr-1
in Mt yr-1
(361,238)
-308.7
6.30
Desjardins (1997)
7.20
Liu (1995)
8.00
Desjardins (1997)
10.40
Liu (1995)
7,159
4
Biomass Burning
0
–
5
Crop Residues
0
–
6
Use of Fertilizers
0
3.2
7
Use of Manures
0
–
8
Nitrogen Fixing Crops
0
–
9
Chemicals
74
–
17,864
–
Sub-Total Crop
Production
10
Farm Animals
0
–
11
Livestock Excretions/Waste
0
–
12
Livestock Management
1,407
–
Sub-Total Livestock
Production
1,407
–
Excluded from this Study*
TOTAL - Source
Liu (1995)
10,631
Fossil Fuels (crops)
TOTAL - Sink
Source for Other
Estimates
2.7
-361,238
-308.70
19,271
17.00
Liu (1995)
Desjardins (1997)
--Not estimated/reported
* These emissions are for stationary combustion.
Source: Column "Estimated Amount": C.E.E.M.A. output. Column "Other Estimates": Source shown in
the last column.
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Table 5.10: Estimated Methane Emissions for Agricultural Production Activities, and
Comparison with Other Study Estimates, 1994
No.
Description
Estimated Amount
Other Estimates
in kt yr-1
in kt yr-1
Source for Other
Estimates
1
Photosynthesis
0
0
2
Soil Organic Matter
0
–
3
Fossil Fuels (crops)
0
2
4
Biomass Burning
0
–
5
Crop Residues
0
–
6
Use of Fertilizers
0
–
7
Use of Manures
0
–
8
Nitrogen Fixing Crops
0
–
9
Chemicals
0
–
Sub-Total Crop
Production
0
2
441
706
Liu (1995)
887
McAllister (1997)
949
276
Liu (1995)
0
–
10
Liu (1995)
Farm Animals
11
Livestock Excretions /
Waste
12
Livestock Management
Sub-Total Livestock
Production
1,390
TOTAL
1,390
984
Liu (1995)
--Not estimated/reported.
Source: Column "Estimated Amount": C.E.E.M.A. output.
However, in spite of these differences, a comparison of these results suggests that the
methodology followed in this study yields results that are comparable to other researchers.
For example, for CO2 emissions, this study estimated a total of 19 Mt, as against 17 Mt by
Desjardins (1997). Similarly for N2O emissions, this study estimated an annual emission level
of 45 kt, as against that by Desjardins (1997) of 62 kt47. Thus, because of the differences in the
scope of investigations, the two studies lead to somewhat different estimates of emissions of
GHGs. For methane, however, the estimate of this study of 1,390 kt is slightly higher than
that by Liu (1995) of 984 kt per annum.
47. This excludes 36 kt of nitrous oxide from sources that were not included in this study.
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Chapter 5
Table 5.11: Estimated Nitrous Oxide Emissions for Agricultural Production Activities,
and Comparison with Other Study Estimates, 1994
No.
Description
Estimated Amount
Other Estimates
in kt yr-1
in kt yr-1
Source for Other
Estimates
1
Photosynthesis
0
–
2
Soil Organic Matter
0
–
3
Fossil Fuels
0.63
–
4
Biomass Burning
0.37
–
5
Crop Residues
24.18
21.00
Desjardins
(1997)
6
Use of Fertilizers
7.21
15.00
Desjardins
(1997)
7
Use of Manures
3.58
–
8
Nitrogen Fixing Crops
3.88
9.00
9
Chemicals
0
–
39.85
45.00
0
–
5.57
17.00
0
–
5.57
17.00
--
36.00
Desjardins
(1997)
45.42
98.00
Desjardins
(1997)
Sub-Total Crop
Production
10
Farm Animals
11
Livestock Excretions /
Waste
12
Livestock Management
Sub-Total Livestock
Production
Excluded from this Study*
TOTAL
Desjardins
(1997)
Desjardins
(1997)
--Not estimated / reported
*These emissions are from atmospheric deposition, nitrogen leaching and runoff, human sewage, and
from other sources.
Source: Column "Estimated Amount": C.E.E.M.A. output.
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Canadian Economic and Emissions Model for Agriculture: Report 1
Results for the Base Scenario
5.5 Regional Distribution
Relative distribution of GHG emissions (in CO2-equivalent levels) by various provinces is
shown in Figure 5.1. Western Canadian provinces contribute more than half of the total
emissions. Distribution of greenhouse gas emission levels by various Canadian provinces is
shown in Table 5.12. In fact, 62.5% of the total Canadian emissions of GHGs are produced by
the Prairie provinces and British Columbia. In the case of Eastern Canada, Ontario and
Quebec produce the larger emissions. These two provinces together contribute almost one
third of the total Canadian emissions.
Figure 5.1 Regional Distribution of Agriculturally-Induced Emissions of Greenhouse
Gases in Canada, 1994
Nfld.
0.11%
B.C.
3.11%
P.E.I.
0.72%
N.S.
0.79%
N.B.
0.54%
Que.
15.96%
Alta.
26.63%
Ont.
17.12%
Sask.
20.69%
Man.
14.22%
Relative distribution of GHGs is identical to that for the CO2-equivalent emisssion levels. For
the CO2 and N2O emissions, Alberta and Saskatchewan are the regions with largest emission
levels. This is because these two provinces have the largest cropped area. For CH4, Alberta,
Ontario, and Quebec produce the largest quantities, because of their relative large scale of
livestock enterprises. Detailed information on the contribution of various agricultural
activities by province is shown in Appendix E.
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Chapter 5
Table 5.12: Distribution of Greenhouse Gas Emissions* in kilo tonnes per year,
Canada by Province, 1994
Production Province
CO2
CH4
N2O
CROP PRODUCTION
British Columbia
335.13
0
1.45
Alberta
7,231.93
0
10.98
Saskatchewan
5,738.92
0
13.77
Manitoba
3,298.63
0
5.09
Ontario
722.38
0
5.05
Quebec
486.07
0
2.85
New Brunswick
-22.57
0
0.22
Prince Edward Island
81.28
0
0.15
Nova Scotia
-7.26
0
0.23
Newfoundland
-0.63
0
0.06
17,863.87
0
39.85
37.34
49.74
0.26
Alberta
330.95
253.33
1.21
Saskatchewan
142.68
123.98
0.62
Manitoba
147.42
176.06
0.58
Ontario
345.34
364.56
1.36
Quebec
342.58
374.01
1.35
New Brunswick
15.44
12.43
0.05
Prince Edward Island
18.47
13.54
0.05
Nova Scotia
24.64
18.16
0.07
2.19
2.38
0.01
1,407.06
1,388.18
5.57
19,270.93
1,388.18
45.42
Total Crops
LIVESTOCK PRODUCTION
British Columbia
Newfoundland
Total Livestock
Grand Total
*Emissions in this table are in non-CO2-equivalent terms. Thus, the methane and nitrous oxide emission
here will not match with those shown in Table 5.8.
Source: C.E.E.M.A. output.
74
Canadian Economic and Emissions Model for Agriculture: Report 1
Chapter 6: Estimation of Greenhouse
Gas Emissions for Selected Scenarios
The development of an empirical model is not complete without testing its forecasting ability
in terms of accuracy and consistency of forecasts based on the model. To this effect, the
C.E.E.M.A. was tested for two situations, called scenarios. The first scenario was related to
the adoption of conservation tillage systems in the Prairie provinces, whereas the second
scenario was related to expansion in the livestock industry in Western Canada. Results for
each of these scenarios are presented in this chapter.
6.1 Study Scenarios
6.1.1 Selection of Study Scenarios
Two policy scenarios were selected for testing the forecasting ability of the C.E.E.M.A.. These
were:
•
increase in the area of “Zero-till or No-till” Tillage System in the Prairies, and
•
increase in Red Meat Production (Beef and Hog Enterprises) in the Prairies.
The reasons for selecting these two scenarios are: ease of running CRAM; policy relevance,
particularly for Western Canada; and, higher contribution of Western Canadian agricultural
activities to the total GHG emissions in Canada. The policy relevance of the first scenario is
high because of frequent recommendations by those endorsing soil conservation through
adoption of conservation tillage systems (minimum-till or no-till). The second scenario was
selected on the grounds that many of the Western provinces are considering major initiatives
to increase the production and processing of livestock products, particularly beef cattle and
hogs. In Saskatchewan, for example, hog production has increased significantly during the
last decade. The number of pigs on farms on January 1, 1987 was 644,000, which increased
46% to 942,000 by January 1, 1995.
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Chapter 6
6.1.2 Description of Study Scenarios
6.1.2.1 Increase in “No-Till” Systems
In this scenario, “no-till” cropped area (excluding area under summerfallow) in Alberta,
Manitoba, and Saskatchewan was doubled, from the present 1.256 million hectares to 2.512
million hectares. The other two types of tillage systems were allowed to adjust to the market
realities and price conditions. The model-based results for estimates of cropped area are
shown in Table 6.1. The increase in the no-till cropped area resulted in a reduction of 5-6% in
the area under the other two types of tillage systems. For example, the cropped area under
intensive tillage decreased by 856,000 hectares, from 16.35 million in 1994. In addition, there
was a minor increase (of 25,000 hectares) in the area under crops for the three prairie
provinces.
Table 6.1: Change in the Area Under Crops, Prairies Provinces, by Tillage Systems,
1994
Area Under the
Scenario*, 103 ha
Area Under the
Scenario, 103 ha
Intensive Tillage
16,350
15,495
-856
-5.2
Medium Tillage
6,463
6,087
-436
-5.8
No Tillage
1,256
2,512
1,256
100.0
24,069
24,094
25
0.1
Tillage System
Total
Change in Area,
103 ha
% Change from
the Base Area
* This area represents that used in the production given demand conditions for various products. It will
not match with figures shown in Table 5.3.
Source: C.E.E.M.A. output.
Under this scenario no-till area under each of the crops was doubled, which resulted, in some
cases, in a net increase in the total area under that crop, while for others, a net decrease.
These results are shown in Table 6.2. Increases in the overall area under the scenario were
noted for canola, durum, lentils and peas. All other crops had a decrease in the area, with
wheat decreasing the most.
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Estimation of Greenhouse Gas Emissions for Selected Scenarios
Table 6.2: Area of Crops under No-Till Tillage System under Scenario One, 1994
Crop
Area under No-Till Tillage
System, 103 Ha
Change in Total Area Under
Scenario, 103 Ha
Wheat
492
-122
Durum
209
54
Barley
172
-16
Oats
75
-27
Flax
39
-4
Canola
213
104
Lentils
31
25
Field Peas
26
15
1,256
26
Total
Source: C.E.E.M.A. output
6.1.2.2 Increase in Livestock Production in Western Canada
In this scenario, red meat production was assumed to increase in the four Western provinces.
It was assumed in this scenario that hog numbers would double, and beef cattle numbers
would increase by 50%. No change in the poultry and dairy enterprises were assumed,
primarily because of their supply management environment. Furthermore, no spill-over
effects on crop or livestock production in Eastern Canada were assumed to take place as a
result of these changes in Western Canada.
Results for the changes in the livestock numbers for the beef and hog enterprises in Western
Canada are shown in Table 6.3. All beef cattle numbers increased approximately by 50%, and
the hog numbers by 100%. In aggregate, the number of head of cattle increased by 4.14
million, an increase of about 48%. The hog numbers in the scenario doubled from the present
herd of 3.2 million to 6.4 million.
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Chapter 6
Table 6.3: Change in the Livestock Inventories for Beef and Hog Enterprises, Western
Canada, Scenario Two, 1994
Particulars
Number of
Livestock in
Scenario in 103
Head
Base Number of
Livestock, in 103
Head
Change in
Number of
Livestock, in
103 Head
% Change from
Base Number
of Livestock
Cow-calf
4,912
3,298
1,613
48.9
Replacement Cattle
1,162
780
382
48.9
Stocker Calves
2,777
1,852
926
50.0
Calves
2,322
1,637
685
41.9
Yearling
1,316
871
445
51.1
262
176
86
48.9
12,752
8,615
4,137
48.0
898
449
449
100.0
Market Pigs
6,419
3,209
3,209
100.0
Total Hogs
7,317
3,658
3,659
100.0
Bulls
Total Beef Cattle
Sows
Source: C.E.E.M.A. output.
Increase in herd size for beef and hog enterprises would result in a change in the land use
pattern in Western Canada, particularly in light of the change in forage demand48. Again, it
was stipulated that the increased demand for feedgrains and forages would be met by
production of these crops within the Western Canadian region, and the Eastern Canadian
region would not experience any significant spill-over effects. Results for the change in the
land use are shown in Table 6.4. In general, area under cereal crops, except for barley,
decreased, whereas various forages increased. The largest relative decline was estimated for
oats, flax, and wheat. In all these cases, area in this scenario was expected to decline by over
10% from the base area. Barley production (both for feed and malting barley) was expected to
increase, as was the area under corn for silage. The net effect on the total cropped area in
Western Canada was to decrease by 1.07 million hectares.
Consistent with the decline in the cropped area is the decrease in the area under
summerfallow. Since it is a significant part of the rotations followed in some soil zones, a
decline in the area under certain cereals, primarily wheat, would also result in a decline in
the area under summerfallow. The decrease in cropped area is transferred to hay production,
which increased by 2.7 million ha, an increase of 81% of the base area. The net result of all
these changes is to decrease the crop and forage land base in Western Canada by 1.15 million
ha, 2.1% of the present base.
48. CRAM specifies a maximum hay land area for each region. If the forage demand generated from livestock
inventories exceeds the available supply, then crop land within the region is converted to hay land in order to
meet the demand.
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Canadian Economic and Emissions Model for Agriculture: Report 1
Estimation of Greenhouse Gas Emissions for Selected Scenarios
Table 6.4: Change in Land Use Pattern, Western Canada, Scenario Two, 1994
Base Period
Area* in
Thousand Ha
Area in Scenario
Two in
Thousand Ha
Wheat
8,281
7,433
-848
-10.2
Durum
2,346
2,255
-91
-3.9
Barley for Feed
1,762
2,212
450
25.6
Malting Barley
2,558
2,877
319
12.5
Oats
1,675
1,384
-291
-17.4
732
640
-92
-12.6
Canola
5,775
5,363
-411
-7.1
Lentils
399
394
24
-1.2
Field Peas
696
665
15
-4.4
8
12
4
52.5
35
35
0
0
937
861
-76
-8.1
25,204
24,131
-1,000
-4.3
6,820
6,352
-467
-6.8
32,024
30,483
-1,467
-4.8
3,332
6,015
2,693
81.1
Improved and
Unimproved Pastures
18,253
18,253
0
0
Total Crop and Forage
Lands
53,599
54,751
1,152
2.1
Particulars
Flaxseed
Corn for Silage
Potatoes
Other Crops
Total Area under Crops
Summerfallow
Total Cropped Area
Hay Land
Change from
Base Area,
Thousand Ha
% Change
*One should note that figures in this column are model output, and may not match with the actual land
use in Chapter 5.
Source: C.E.E.M.A. Output.
6.2 Results for Increase in No-Till System Scenario
The adoption of no-till tillage systems on 1.26 million ha in the Prairies would slightly reduce
the total GHG emissions in Canada. As shown in Table 6.5, in this scenario, emissions of all
gases are reduced by 242 kt per annum in CO2-equivalent basis. The change is only 0.39% of
the base crop production emission level in Canada. However, since the scenario considered
the adoption of no-tillage systems on only about 5% of the total Prairie cropland, widespread
adoption of conservation tillage would lead to more significant reductions in greenhouse gas
emissions. Since there is no change in the size of livestock enterprises, change in emissions
from livestock production is zero, and therefore, not shown here.
Canadian Economic and Emissions Model for Agriculture: Report 1
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Chapter 6
Table 6.5: Total Emissions from Crop and Livestock Production, Canada, by Gas in
CO2-equivalent Level, Scenario One
Emissions under
Scenario, kt
Change from Base
kt
% Change
Carbon dioxide
19,041
-230
-1.19
Methane
29,152
0
0
Nitrous Oxide
14,067
-12
-0.09
Total All Gases
62,260
-242
-0.39
Particulars
Source: C.E.E.M.A. output.
Let us examine emissions for individual GHGs. For the CO2, among activities that affect
emission levels under the adoption of no-till systems, emission levels of GHGs are reduced
through smaller losses of soil carbon, and through reduced use of fossil fuels, and burning of
biomass (Table 6.6). The last reduction is because of the decrease in the area under crops,
particularly flaxseed. However, emissions increase due to the use of chemicals and manure.
Table 6.6: Total Carbon Dioxide Emissions by Agricultural Activities, Canada,
Scenario One
Activity
Level of Emissions
under Scenario in kt
Change from Base in
kt
% Change from
Base
Biomass Burning
0
0
0
Crop Residues
0
0
0
Fertilizer
0
0
0
7,108
-52
-0.72
0
0
0
75
1
0.97
0
0
0
Soil Organic Matter
10,452
-179
-1.68
Total Crop Emissions
17,634
-230
-1.29
Livestock Production
1,407
0
0
19,041
-230
-1.19
Fossil Fuel
Manure
Chemicals
Nitrogen Fixing Crops
Total Emissions
Source: C.E.E.M.A. output.
Since CH4 emissions remain unchanged, no further discussion of these is needed. For the
emissions of N2O, results are shown in Table 6.7. The agriculture production activities related
to these emission levels are similar to those for the CO2, except here on account of increased
area for lentils and field peas, emissions increase, because of release of nitrogen fixation by
these crops.
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Canadian Economic and Emissions Model for Agriculture: Report 1
Estimation of Greenhouse Gas Emissions for Selected Scenarios
Regional distribution of CO2 emissions is shown in Table 6.8, and of N2O in Table 6.9. Figures
are presented by province only for the Western provinces. Also both actual levels and CO2equivalent emission levels are included.
Table 6.7: Total Nitrous Oxide Emissions, Absolute and CO2-equivalent, Canada,
Scenario One
Activity
Biomass Burning
Emissions
under Scenario
kt
Emissions in
CO2-equivalent k
Change from
Base Level
(CO2equivalent) k
% Change from
Base Levels
0.37
114
-0.84
-0.73
24.15
7,485
-9.85
-0.13
Fertilizer
7.15
2,226
-4.13
-0.19
Manure
3.58
1,110
-0.21
-0.02
Fossil Fuel
0.62
194
-1.59
-0.82
Chemicals
0
0
0
0
3.90
1,209
4.50
0.37
0
0
0
0
39.81
12,338
-12.12
-0.10
5.57
1,729
0
0
45.38
14,067
-12.12
-0.10
Crop Residues
Nitrogen Fixing Crops
Soil Organic Matter
Total Crop Emissions
Livestock Production
Total Emissions
Source: C.E.E.M.A. output
Table 6.8: Carbon Dioxide Emissions, Canada by Provinces, Scenario One
Province
British Columbia
Emissions under
Scenario in kt
Change in Emissions
from Base Scenario in
kt
% Change from Base
372
0
0
Alberta
7,537
-26
-0.34
Saskatchewan
5,689
-192
-3.27
Manitoba
3,422
-24
-0.68
Total W. Canada
17,020
-242
-1.40
Eastern Canada
2,021
0
0
19,041
-242
-1.26
Total Canada
Source: C.E.E.M.A. output.
Canadian Economic and Emissions Model for Agriculture: Report 1
81
Chapter 6
Table 6.9: Nitrous Oxide Emissions, Absolute and CO2-equivalent and Actual, by
Province, Scenario One
Province
Emissions under
Scenario kt
British Columbia
CO2-equivalent
Emissions kt
Change in CO2equivalent
Emissions from
Base kt
% Change from
Base
1.45
449
0
0
Alberta
10.98
3,404
-0.78
-0.12
Saskatchewan
13.73
4,258
-10.81
-0.25
5.08
1,575
-2.15
-0.14
Total W. Canada
31.34
9,686
-12.18
-0.13
Eastern Canada
11.45
4,381
0
0
Total Canada
45.38
14,067
-12.18
-0.10
Manitoba
Source: C.E.E.M.A. output.
According to the results of this scenario, expansion of the conservation tillage system
reduced total emissions of GHGs. In this scenario, the total cropped area under no-till tillage
systems was increased by 5% of the total (1.256 million hectares), which decreased the total
CO2-equivalent emissions by 242 kt per annum. Thus, every hectare converted into no-till
tillage system leads to a reduction of 0.193 tonnes of CO2-equivalent GHG emissions. If the
15.5 million hectares currently under intensive tillage were converted to no-till, CO2equivalent GHG emissions would be reduced by 2,991 kt per annum. If no-till farming
replaced intensive tillage systems as the dominant method of crop production, significant
reductions in emissions of CO2 and N2O could be expected.
6.3 Results for Livestock Expansion
6.3.1 Emissions in CO2-equivalent Levels
Expansion of red meat production in Western Canada could have a significant impact on the
GHG emissions from agricultural activities, as shown in Table 6.10. Results are presented for
the three GHGs in CO2-equivalent form. In this scenario, total emissions of GHGs are
estimated to increase by 10.82 Mt per annum. About 94% of these increased GHG emissions
are generated by livestock production and related activities. The remaining 6% occurs
indirectly through changes in crop mix induced by increased livestock production. As noted
above, increased livestock production requires increased production of feedgrains and
forages, which alter the crop mix of the region. The change in this crop mix gives rise to a
different GHG emission level from that estimated for the base situation. In terms of the
distribution, all three gases are emitted in almost equal proportions, with CH4 leading the
way at about 85% of the total change in emission level.
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Canadian Economic and Emissions Model for Agriculture: Report 1
Estimation of Greenhouse Gas Emissions for Selected Scenarios
Table 6.10: Total GHG Emissions in CO2 Equivalence by Gas, Canada, Scenario Two
Gas
Level in CO2equivalent Amount,
kt
Change from Base,
kt
% Change from
Base
CROP PRODUCTION
Carbon Dioxide
18,023
159
0.89
0
0
0
Nitrous Oxide
12,857
504
4.08
Total
30,880
603
2.19
1,896
488
34.71
38,378
9,227
31.65
2,169
443
25.66
Total
42,443
10,158
31.46
Grand Total
73,322
10,821
17.31
Methane
LIVESTOCK PRODUCTION
Carbon Dioxide
Methane
Nitrous Oxide
Source: C.E.E.M.A. output.
6.3.2 Individual Greenhouse Gases
Details on individual GHGs, both in terms of actual change, and in terms of CO2-equivalent
changes for various agricultural activities, are presented in Table 6.11. The results are
presented in both actual and CO2-equivalent level of emissions.
Emissions of CO2 in the expanded livestock (red meats) production scenario increase by 3.4%
of the base emissions level. Much of this increase (81% of the total) is a result of increased
livestock numbers. Within crop production-related emissions, a small amount is added by
the use of fossil fuels, and chemicals.
Emissions of CH4 are generated solely from livestock production, particularly through
livestock excretions/wastes. In this scenario, CH4 emissions increase by 31.6% of the base
level of emissions.
Although N2O emissions in absolute terms are small, their effect is almost comparable to that
of CO2, in terms of their potential for global warming. Under this scenario, emissions levels
increase by 6.73%. Increase in the area under nitrogen fixing crops leads to emissions of soil
nitrogen as N2O. In addition, production of animal excretions/wastes is the other leading
source of N2O emissions.
Canadian Economic and Emissions Model for Agriculture: Report 1
83
84
0
--
Fertilizer
Manure
Source: C.E.E.M.A. output.
–Less than one kilo tonne
19,918
1,896
Sub-Total Livestock
Grand Total
0
1,896
Animal Excretions/
Wastes
Livestock Management
Raising Livestock
0
18,023
Sub-Total Crops
LIVESTOCK PRODUCTION
10,678
0
74
Soil Organic Matter
Nitrogen Fixing Crops
Chemicals
7,270
0
Crop Residues
Fossil Fuels
0
Actual
Emissions
kt
Biomass Burning
CROP PRODUCTION
GHG Emissions Activity
CO2
3.36
34.71
0
34.71
0
0.89
0.45
0
0.58
1.54
0.07
0
0
0
% Change
from base
1,828
1,828
1,301
0
526
0
0
0
0
0
0
0
0
0
Actual Level
kt
38,378
38,378
27,326
0
11,052
0
0
0
0
0
0
0
0
0
31.65
31.65
37.4
0
19.31
0
0
0
0
0
0
0
0
0
48.47
7
7
0
0
41.47
0
5.61
0
0.64
3.59
7.14
24.13
0.36
15,026
2,169
2,169
6
0
12,857
0
1,739
0
198
1,113
2,215
7,481
111
CO2-Eqv.
Level
kt
Actual Level
kt
CO2-Eqv.
Level
kt
% Change
N2O
CH4
Table 6.11: Total Greenhouse Gas Emissions in CO2-equivalent, by Gas and Emission Activity, Scenario Two
6.73
25.66
25.66
0
0
4.08
0
44.46
0
1.64
0.26
-0.87
-0.19
-3.18
% Change
Chapter 6
Canadian Economic and Emissions Model for Agriculture: Report 1
Estimation of Greenhouse Gas Emissions for Selected Scenarios
6.3.3 Regional Distribution of Emissions Levels
Change in red meat production in Western Canada will affect primarily the emissions of
GHGs in Western Canada provinces. The results are shown in Table 6.12 for CO2, in Table
6.13 for CH4, and in Table 6.14 for N2O. For CO2 and CH4, the largest increase in emission
levels was noted in Alberta, followed by Manitoba. For CH4 emissions, all three Prairie
provinces experienced similar increases. These results are consistent with the distribution of
livestock numbers in these provinces. Some small amounts of emissions levels are also
generated by Eastern Canadian provinces; however, the amounts are insignificant, and can
be assumed to be zero.
Table 6.12: Carbon Dioxide Emissions by Regions, Scenario Two
Actual Emissions
in kt
Change from Base in
kt
% Change from
Base
212.51
-122.62
-36.59
Alberta
7,476.81
244.83
3.39
Saskatchewan
5,687.04
-51.90
-0.90
Manitoba
3,390.52
91.89
2.79
16,766.88
162.19
0.98
1,255.84
-3.43
-0.27
18,022.72
158.76
0.89
60.02
22.36
60.73
Alberta
562.43
231.48
69.95
Saskatchewan
243.36
100.68
70.56
Manitoba
284.32
136.90
92.87
1,150.14
491.74
74.69
745.38
-3.28
-0.44
1,895.52
488.46
34.71
19,918.24
647.22
3.36
Province
CROP PRODUCTION
British Columbia
Western Canada Total
Eastern Canada
Total Canada - Crops
LIVESTOCK PRODUCTION
British Columbia
Western Canada Total
Eastern Canada
Total Canada - Livestock
Grand Total
Source: C.E.E.M.A. output.
Canadian Economic and Emissions Model for Agriculture: Report 1
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Chapter 6
Table 6.13: Methane Emissions by Regions, Scenario Two
Province
Actual
Emissions in kt
CO2-equivalent
Emissions in kt
Change in CO2equivalent
from Base in kt
% Change from
Base
CROP PRODUCTION
British Columbia
0
0
0
0
Alberta
0
0
0
0
Saskatchewan
0
0
0
0
Manitoba
0
0
0
0
Western Canada Total
0
0
0
0
Eastern Canada
0
0
0
0
Total Canada - Crops
0
0
0
0
74.88
1,572.00
528.00
50.53
Alberta
437.21
9,181.00
3,861.00
72.58
Saskatchewan
211.23
4,436.00
1,832.00
70.37
Manitoba
321.10
6,743.00
3,046.00
82.38
1,044.42
21,933.00
9,267.00
73.17
783.13
16,446.00
(41.00)
-0.25
1827.55
38,378.00
9,227.00
31.65
LIVESTOCK PRODUCTION
British Columbia
Western Canada Total
Eastern Canada
Total Canada - Livestock
Source: C.E.E.M.A. output.
86
Canadian Economic and Emissions Model for Agriculture: Report 1
Estimation of Greenhouse Gas Emissions for Selected Scenarios
Table 6.14: Nitrous Oxide Emissions by Regions, Scenario Two
Province
Actual
Emissions in kt
CO2-equivalent
Emissions in kt
Change in CO2equivalent
Emissions from
Base in kt
% Change from
Base
CROP PRODUCTION
British Columbia
1.53
473.00
24.00
5.26
Alberta
12.06
3,740.00
336.00
9.88
Saskatchewan
13.97
4,331.00
63.00
1.48
5.42
1,679.00
102.00
6.49
32.98
10,223.00
526.00
5.42
8.50
2,634.00
-21.00
-0.80
41.47
12,857.00
504.00
4.08
British Columbia
0.33
102.00
22.00
27.64
Alberta
1.88
583.00
209.00
55.73
Saskatchewan
0.96
298.00
106.00
55.02
Manitoba
0.96
297.00
116.00
64.20
Western Canada Total
4.13
1,280.00
453.00
54.69
Eastern Canada
2.87
888.00
-10.00
-1.09
Total Canada Livestock
7.00
2,168.00
443.00
25.66
48.47
15,026.00
947.00
6.73
Manitoba
Western Canada Total
Eastern Canada
Total Canada Crops
LIVESTOCK PRODUCTION
Grand Total
Source: C.E.E.M.A. output.
Canadian Economic and Emissions Model for Agriculture: Report 1
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Chapter 7: Summary and Future
Research Areas
A major change in the world climatic patterns could translate into significant impacts on the
economic systems of the world. For this reason, climatic changes are regarded as a major
threat to the future sustainability of present economic activities, and some changes, both in
terms of the nature of anthropogenic activities as well as environmental policies, have to be
devised. Given this predicament, various countries including Canada, signed an agreement
on the Framework Convention for Climate Change in 1991. Under this convention, countries
were expected to quantify the GHG emissions related to their anthropogenic activities. This
study was undertaken to account for agricultural production activities49, and in particular
major crop and livestock production activities.
7.1
Summary
The primary objective of this study was to develop a methodology to estimate GHG
emissions related to crop and livestock production in Canada, and its regions. In addition,
the methodology was to be made compatible with the existing policy simulation model of
Agriculture and Agri-Food Canada, CRAM. A secondary objective was to demonstrate the
use of the methodology developed in the study to two somewhat simple scenarios. These
scenarios were: an increase in the area under no-till farming, and expansion of livestock
production in Western Canada.
To meet the above objectives, a model called C.E.E.M.A. was developed. This contained two
sub-models, one for economic planning (resource allocation), and the other for estimation of
GHG emissions. The economic planning sub-model was the existing CRAM. In the GHG
emissions sub-model, three greenhouse gases were included in this study: carbon dioxide,
methane, and nitrous oxide. The methodology for estimating their emissions involved first a
conceptual identification of linkages among various agricultural production activities and
the emissions of the three gases. As a result, the GHG emissions from nine crop production
activities and three livestock production activities were quantified using C.E.E.M.A.. For
49. One should note that the scope of agricultural activities as defined here is somewhat narrower than the entire
gamut of agricultural activities in Canada.
Canadian Economic and Emissions Model for Agriculture: Report 1
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Chapter 7
crops, these included: photosynthesis, loss of soil carbon through loss of organic matter,
application of energy inputs, such as burning of fossil fuels, either directly by farmers or
indirectly (through the use of electricity, burning of crop biomass, use of fertilizers, use of
manure in crop and pasture fields, growing of nitrogen fixing crops, and use of chemicals.
For livestock production, these included: raising of farm animals, livestock excretions/
wastes, and livestock management activities. Of these activities, photosynthesis and SOM
were considered to be potential sinks of GHGs, while the other ten were, on a net basis,
sources of GHGs. However, studies of SOM loss have suggested that even this activity could
be both a sink and a source. Therefore, in this study, SOM was estimated as a net source of
GHGs.
In order to make the methodology of estimating GHG emissions compatible with CRAM,
Canada was disaggregated into 29 crop production regions, and into 10 livestock production
regions. For crop production, each province, with the exception of the three Prairie
provinces, was treated as a single region. The Prairie provinces were further divided into
several sub-regions50. For the Prairie provinces, there were three alternative tillage systems:
intensive (or conventional), medium (or minimum till), and no-till (or zero till).
The emission level for a GHG was estimated by multiplying the scale of production by an
EC. The GHG emissions sub-model was linked with CRAM at its scale of production levels.
Thus, the major effort of the study was to estimate the average EC for each GHG and for each
of the relevant crop and livestock activities identified in CRAM. Secondary information
provided the basis to estimate various EC in this study. To accomplish this, a review of
existing studies was undertaken, starting first with the Canadian studies. When Canadian
studies were inadequate to provide a basis to estimate the coefficient, international studies,
particularly those used by the IPCC were consulted.
Results from the C.E.E.M.A. were obtained for the year 1994. CRAM was calibrated to reflect
the level of these enterprises. The total area under cereal crops and forages (including
improved and unimproved pastures) was estimated to be 65.6 million hectares. About 42
million hectares of this were under crops and summerfallow, and the remaining 23.6 million
hectares under hay production and pastures (improved and unimproved). For Canada as a
whole, wheat and canola were the major crops, constituting slightly over half the total
cropped lands, excluding summerfallow.
The livestock enterprises included in this study were: beef cattle, hogs, dairy cattle, and
poultry production. The beef herd was estimated to consist of 10.6 million head. Similarly,
hog inventories per period were estimated at 9 million sows and grower pigs. Dairy
inventories included a herd of 2.7 million, and the poultry production was based on almost
319 million birds, which included broilers, egg layers, and turkeys.
7.2 Major Conclusions
Although the major purpose of this study was to develop a methodology for the estimation
of emission levels of major GHGs from agricultural production practices, some results were
obtained on the nature of contribution agriculture makes to these emissions. These became
the basis for the following conclusions:
50. The following is the number of sub-regions in Prairie provinces: Alberta: 7 sub-regions; Saskatchewan: 9 subregions; and Manitoba: 6 sub-regions.
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Canadian Economic and Emissions Model for Agriculture: Report 1
Summary and Future Research Areas
•
Production of various cereal and forage crops in Canada serves both as a source
and a sink for CO2. In terms of the sink, in 1994, it is estimated that 361 Mt of CO2
were fixed in plant tissue through photosynthesis. However, one should
recognize that this activity is an integral part of the carbon cycle. A number of
activities that are not considered in this study could reduce this amount. In
addition, this estimated level of sink is contingent upon the scope of agriculture
as defined in this study. Some of the cereals and forages are consumed by people
and/or used for further processing. It is conceivable that use of agricultural
products would be responsible for some emissions of GHGs, either in Canada or
wherever cereals are consumed, if exported. Some of these emissions were not
included in this study.
•
In terms of agriculture production as a source of GHGs, this study estimated the
total contribution to be 62.5 Mt per annum in terms of their global warming
potential (CO2-equivalent). Crop production contributed slightly under half of
these emissions.
•
Methane is the major greenhouse gas emitted from agricultural operations, when
all gases are converted in terms of their global warming potential. This gas
contributes about 47% of total emissions; nitrous oxide makes the smallest
relative contribution (22.6%) among the three GHGs.
•
In terms of global warming potential, animal excretions/wastes, and loss of soil
carbon through loss of organic matter are the major contributors to the total GHG
emissions from agricultural production. These two sources generate about 52% of
the total.
•
Regional distribution of emission levels suggests that the Western provinces
contribute a significantly higher level of GHG emissions from crop production,
whereas the Eastern provinces from livestock production. The following shares
are estimated:
Crop Products
Livestock Products
All Agricultural
Products
(Share of total Canadian emissions)
Western Canada
87%
44%
65%
Eastern Canada
13%
56%
35%
Thus, for all agricultural products, Western Canada’s share is 65% of the total. Much
of this contribution is because of the concentration of crop production in Western
Canada, which is responsible for 48% of all emissions in terms of CO2-equivalents.
•
A comparison of the estimates of this study with those of other studies showed
they were fairly close. This suggests that the methodology used in this study is
consistent with those of major Canadian studies. This is not to suggest that
methodology followed here is without limitations.
•
According to the results of the first scenario, expansion of the conservation tillage
system reduced total emissions of GHGs. A doubling of the no-till area from 1,256
hectares to 2,512 hectares, which affected only about 5% of the crop land on the
prairies, resulted in small reductions in both CO2 and N2O emissions. If no-till
Canadian Economic and Emissions Model for Agriculture: Report 1
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Chapter 7
farming replaced intensive tillage systems as the dominant method of crop
production, significant reductions in emissions of CO2 and N2O could be
expected.
•
Expansion of red meat production in Western Canada will have implications for
the emissions. In terms of global warming potential, the total emissions in CO2equivalent terms increase by 10.8 Mt per annum from the base line emissions. The
largest part of this increase is caused by methane emissions from the increased
number of farm animals.
In terms of the methodology developed in this study, it is concluded that a disaggregate
modelling of GHG emissions is feasible. Such an approach is more desirable than the
aggregate approaches, since it is capable of providing the decision makers with not only a
glimpse of the regional distribution, but also of how different agricultural practices could
reduce emission levels. The accuracy of the results, of course, is subject to the availability of
appropriate information for estimating emissions coefficients.
7.3 Areas for Future Research
Although this study has been successful in developing a “blue-print” of a methodology for
estimating GHG emissions from agricultural production in Canada, a number of areas
remain where refinements in the methodology would yield better results. The following
areas are recommended for further work related to the focus of this study:
92
•
Grafting of Scientific Knowledge on Policy Modelling: In order to assure policy
analysis is consistent with the latest development in scientific fields, there is a
continual need to update the basis/justification for calculation of ECs. This would
require a cooperative effort between the scientific community and the model
developers and policy analysts.
•
Provide Deficient Information for Emission Coefficients: In spite of the best effort
to find secondary information, a number of deficiencies remain in the
methodology reported in this study. Among those noteworthy are: farm level
practices related to the use of animal excretions/wastes as manure; practices
related to pasture animals; a more detailed examination of emissions from
chemicals; collection of input levels for various crops, particularly those grown in
Eastern Canada; and, a more detailed examination of standard practices of tillage
systems.
•
Maintain Consistency between CRAM Coefficients and Emission Coefficients: At
the time of writing, CRAM coefficients and those for this study were developed
independently. In order to achieve full consistency and compatibility between the
two sub-models, basic data for the estimation of their coefficients should be the
same. Correlating these data should be attempted as and when the CRAM
coefficients are updated.
•
Expand the Scope of Estimation of Emission of Greenhouse Gases: The scope of
estimation in this study was limited to major crop and livestock enterprises on
farms. A comprehensive account of various types of GHG emissions associated
with agricultural activities is shown in Figure 7.1. Besides including crop and
livestock enterprises excluded from the present analysis, several other activities,
such as production and procurement of farm inputs, marketing of farm output,
Canadian Economic and Emissions Model for Agriculture: Report 1
Summary and Future Research Areas
other farm operations not directly linked to crop or livestock production, and
processing of farm products, are worthy of further examination. Therefore, the
scope of such an investigation can be extended in the following manner:
• Add other farm level production activities to the present study. These will
include: horticultural and other cash crops, and other livestock enterprises
not included.
• Add the farm input sectors. Production and marketing of farm inputs use
various types of energy. These uses result in emissions of GHGs. In order to
develop a comprehensive estimate of emissions from agricultural operations,
both direct and embodied energy uses should be included.
• Add the energy inputs required for the marketing of crops and livestock
products from the farm gate.
• Include other farm operations which were excluded from the above analysis,
including use of energy inputs in operations included under overhead
activities, use of farm shelterbelts, and use of farm products for home use.
• Include emissions from agricultural processing industries.
• Include emissions from end-users of agricultural products (human
consumption, for example).
•
Conduct policy analysis for reducing emissions of GHGs through changes in
agricultural practices: A major challenge facing many countries, including
Canada, is to devise ways and means to reduce GHG emissions, and thereby
reduce the threat of global warming, without unduly retarding the pace of
economic growth in the agriculture sector in the short-run. Work on identifying
such avenues has already begun. For example, Dumanski et al. (1996) suggested
that land use changes, application of improved soil conservation and
management technologies can sequester atmospheric CO2 and thus reduce the
prospect of global change. Hedger (1996) suggested a number of options for the
agriculture sector, including a review of programs and policies to ensure cross
compliance with environmental objectives. However, in addition to identifying
potential avenues, there exists a need for measuring the effect of selected options
on emission levels. Since Canadian agriculture is a very heterogenous industry
extending over various parts of the country, a regional disaggregation is
preferable. Here the methodology developed in this study, along with
improvements outlined above, can be very helpful.
•
Use a Multi-criteria Analysis of Policy Options: In addition to estimating the
impact of policy options on emission levels, environmental policy analysis
requires knowledge of trade-offs and compromises that need to be made by
decision makers. A multi-criteria evaluation of the selected option would lead to
the selection of better programs and policies.
Canadian Economic and Emissions Model for Agriculture: Report 1
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Chapter 7
Figure 7.1 Sources of Emissions of Greenhouse Gases from Agriculture and AgriFood Sector
PRODUCTION OF
FARM INPUTS
PROCUREMENT
OF FARM INPUTS
OTHER
CROPS
OTHER
LIVESTOCK
PRODUCTS
CROP & FORAGE
PRODUCTION
MARKETING &
TRANSPORTATION
OF CROPS
EMISSIONS OF
GREENHOUSE GASES
FROM THE CANADIAN
AGRICULTURE &
AGRI-FOOD SECTOR
MAJOR
LIVESTOCK
PRODUCTION
MARKETING &
TRANSPORTATION
OF LIVESTOCK
OTHER FARM
OPERATIONS
AGRICULTURAL
PROCESSING
HUMAN CONSUMPTION
EXPORTS
EMISSIONS IN
REST OF THE
WORLD
This study marks the beginning of a policy analysis of greenhouse gas emissions from
agriculture. More research and refinements in the methodology are needed to succeed in
meeting the challenge posed by the global climate change both in the context of Canada and
the world.
94
Canadian Economic and Emissions Model for Agriculture: Report 1
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102
Canadian Economic and Emissions Model for Agriculture: Report 1
Appendix A: Specification of Regions
and Production Activities in C.E.E.M.A.
Table A.1: Regional Disaggregation for CEEMA
Acronym
Number of
Sub-Regions
in C.E.E.M.A.1
No. of regions
in the Crop
GHGE Submodel
British Columbia
BC
0
1
1
Alberta
AL
7
7
1
Saskatchewan
SA
9
9
1
Manitoba
MA
6
6
1
Ontario
ON
0
1
1
Quebec
QU
0
1
1
New Brunswick
NB
0
1
1
Prince Edward Island
PE
0
1
1
Nova Scotia
NS
0
1
1
Newfoundland
NF
0
1
1
29
10
Name of the Region
Total No. of Regions
No. of regions in the
Livestock GHGE
Sub-model
1 Where CRAM did not have any sub-regions, the province as a whole was modelled.
Canadian Economic and Emissions Model for Agriculture: Report 1
A-1
Appendix
Table A.2: Specification of Crop Production Activities in C.E.E.M.A.
Crop Production Activity Number and Acronym
Crop Production Activity Description
1. BAR
Barley
2. BARFD
All feed barley
3. BARFDI
All feed barley - intensive tillage
4. BARFDM
All feed barley - moderate tillage
5. BARFDN
All feed barley - no tillage
6. BARFDSB
Feed barley on stubble
7. BARFDSBI
Feed barley on stubble - intensive tillage
8. BARFDSBM
Feed barley on stubble - moderate tillage
9. BARFDSBN
Feed barley on stubble - no tillage
10. BARFDSF
Feed barley on stubble - summerfallow
11. BARMT
All malting barley
12. BARMTI
All malting barley - intensive tillage
13. BARMTM
All malting barley - moderate tillage
14. BARMTN
All malting barley - no tillage
15. BARMTSB
Malting barley on stubble
16. BARMTSBI
Malting barley on stubble - intensive tillage
17. BARMTSBM
Malting barley on stubble - moderate tillage
18. BARMTSBN
Malting barley on stubble - no tillage
19. BARMTSF
Malting barley on summerfallow
20. CAN
Canola
21. CANOLA
All canola
22. CANOLAI
All canola - intensive tillage
23. CANOLAM
All canola - moderate tillage
24. CANOLAN
All canola - no tillage
25. CANSB
Canola on stubble
26. CANSBI
Canola on stubble - intensive tillage
27. CANSBM
Canola on stubble - moderate tillage
28. CANSBN
Canola on stubble - no tillage
29. CANSF
Canola on summerfallow
30. CANSFI
Canola on summerfallow - intensive tillage
31. CANSFM
Canola on summerfallow - moderate tillage
A-2
Canadian Economic and Emissions Model for Agriculture: Report 1
Table A.2: Specification of Crop Production Activities in C.E.E.M.A.
Crop Production Activity Number and Acronym
Crop Production Activity Description
32. CANSFN
Canola on summerfallow - no tillage
33. CORNG
Corn grain
34. CORNS
Corn silage
35. DURUM
All Durum
36. DURUMN
All durum - no tillage
37. DURUMSB
Durum on stubble
38. DURUMSBI
Durum on stubble - intensive tillage
39. DURUMSBM
Durum on stubble - moderate tillage
40. DURUMSBN
Durum on stubble - no tillage
41. DURUMSF
Durum on summerfallow
42. DURUMSFI
Durum on summerfallow - intensive tillage
43. DURUMSFM
Durum on summerfallow - moderate tillage
44. DURUMSFN
Durum on summerfallow - no tillage
45. FLAX
All flax
46. FLAXI
All flax - intensive tillage
47. FLAXM
All flax - moderate tillage
48. FLAXN
All flax - no tillage
49. FLAXSB
Flax on stubble
50. FLAXSBI
Flax on stubble - intensive tillage
51. FLAXSBM
Flax on stubble - moderate tillage
52. FLAXSBN
Flax on stubble - no tillage
53. FLAXSF
Flax on summerfallow
54. FLDP
Field peas
55. FLDPEAS
All field peas
56. FLDPEASI
All field peas - intensive tillage
57. FLDPEASM
All field peas - moderate tillage
58. FLDPEASN
All field peas - no tillage
59. FLDPSB
Field peas on stubble
60. FLDPSBI
Field peas on stubble - intensive tillage
61.FLDPSBM
Field peas on stubble - moderate tillage
62. FLDPSBN
Field peas on stubble - no tillage
Canadian Economic and Emissions Model for Agriculture: Report 1
A-3
Appendix
Table A.2: Specification of Crop Production Activities in C.E.E.M.A.
Crop Production Activity Number and Acronym
Crop Production Activity Description
63. HAY
Tame hay
64. LENT
Lentils
65. LENTILS
All lentils
66. LENTILSI
All lentils - intensive tillage
67. LENTILSM
All lentils - moderate tillage
68. LENTILSN
All lentils - no tillage
69. LENTSB
Lentils on stubble
70. LENTSBI
Lentils on stubble - intensive tillage
71. LENTSBM
Lentils on stubble - moderate tillage
72. LENTSBN
Lentils on stubble - no tillage
73. LENTSF
Lentils on summerfallow
74. LENTSFI
Lentils on summerfallow - intensive tillage
75. OATS
All oats
76. OATSI
All oats - intensive tillage
77.OATSM
All oats - moderate tillage
78. OATSN
All oats - no tillage
79. OATSSB
Oats on stubble
80. OATSSBI
Oats on stubble - intensive tillage
81. OATSSBM
Oats on stubble - moderate tillage
82. OATSSBN
Oats on stubble - no tillage
83. OATSSF
Oats on fallow
84. OTHER
All other crops
85.OTHERC
Other Crops
86. OTHSB
Other crops on stubble
87. OTHSF
Other crops on summerfallow
88. PAST
Tame pasture
89. POTAT
Potatoes
90. SOY
Soybeans
91. SOYBEANS
All soybeans
92. SUMFAL
Summerfallow
93. SUMFALI
Summerfallow - intensive tillage
A-4
Canadian Economic and Emissions Model for Agriculture: Report 1
Table A.2: Specification of Crop Production Activities in C.E.E.M.A.
Crop Production Activity Number and Acronym
Crop Production Activity Description
94. SUMFALM
Summerfallow - moderate tillage
95. SUMFALN
Summerfallow - no tillage
96. UILPAST
Unimproved land pasture
97. WHEAT
All wheat
98. WHEATI
All wheat - intensive tillage
99. WHEATM
All wheat - moderate tillage
100. WHEATN
All wheat - no tillage
101. WHTQ
Wheat
102. WHTHQSB
Wheat on stubble
103. WHTHQSBI
Wheat on stubble - intensive tillage
104. WHTHQSBM
Wheat on stubble - moderate tillage
105. WHTHQSBN
Wheat on stubble - no tillage
106. WHTHQSF
Wheat on summerfallow
107. WHTHQSFI
Wheat on summerfallow - intensive tillage
108. WHTHQSFM
Wheat on summerfallow - moderate tillage
109. WHTHQSFN
Wheat on summerfallow - no tillage
Canadian Economic and Emissions Model for Agriculture: Report 1
A-5
Appendix
Table A.3: Specification of Livestock Production Activities In CEEMA
Activity No. and Acronym
Activity Description
1. COWS
Number of beef cows
2. COWCLF1
Cow-calf diet 1
3. COWCLF2
Cow-calf diet 2
4. COWCLF3
Cow-calf diet 3
5. BREPLACE
Beef cattle replacements
6. FEEDER
Feeder calves
7.FEDCLF1
Feeder calves Diet 1
8. FEDCLF2
Feeder calves Diet 2
9. FEDCLF3
Feeder calves Diet 3
10. FEDCLF4
Feeder calves Diet 4
11. FEDYEAR
Feeder yearlings
12. FEDYER1
Feeder yearlings diet 1
13. FEDYER2
Feeder yearlings diet 2
14. FEDYER3
Feeder yearlings diet 3
15. FEDYER4
Feeder yearlings diet 4
16. STOCKER
Stockers
17. PASTYEAR
Pasture yearlings
18. FEDLYEAR
Feedlot long yearlings
19. BULLS
Beef bulls
20. IDAIRY
Dairy animals
21. DCOWS
Dairy cows
22. DARYHEIF
Dairy heifers
23. DHEIFCV
Heifer calves
24. TURKEYS
Turkeys
25. LAYERS
Egg layer birds
26. BROILERS
Broilers
27. SOWT1
Sows time 1
28. SOWT2
Sows time 2
29. GROWERT1
Grower pigs time 1
30. GROWERT2
Grower pigs time 2
A-6
Canadian Economic and Emissions Model for Agriculture: Report 1
Table A.4: List of Acronyms Used in the Greenhouse Gas Emission Sub-Model
Activity No.
Description
Acronym
1
Photosynthesis
PHOSYNTHS
2
Soil Organic Matter
SOLORGMTR
3
Fossil Fuels (Including
crop management activities)
FOSLFUELS
4
Biomass Burning
BIOMSBURN
5
Crop Residues
CRPRESIDU
6
Use of Fertilizers
FERTLIZER
7
Use of Manures
MANURES
8
Nitrogen Fixing Crops
NTROGNFIX
9
Chemicals
HERBICIDS
10
Farm Animals
LIVESTOCK
11
Livestock Excretions /
Wastes
LVSTKWSTE
12
Livestock Management
LVSTKMNGT
Canadian Economic and Emissions Model for Agriculture: Report 1
A-7
Appendix B: Comparison of Soil
Carbon Loss by Provinces
As noted in Chapter 4, in this study, loss of soil carbon was estimated by using information
for various crops and tillage systems. One of the cross-checks for the results was a
comparison with other studies. The study by Smith, Rochette and Jaques (1995) was selected
for this comparison. Results of this comparison are shown in Table B.1.
Table B.1: Estimated Change in Carbon in Agricultural Soils, by Province
Carbon Loss from Agriculture Soils in kg ha-1 yr-1
Region/Province
This Study
Atlantic
Newfoundland
-1.20
-4.26
-0.10
Nova Scotia
1.32
Prince Edward Island
2.31
New Brunswick
Smith, Rochette and Jaques'
(1995) Study
-2.08
Quebec
34.94
34.5
Ontario
3.06
4.12
Manitoba
79.95
66.10
Saskatchewan
32.02
22.50
Alberta
74.36
74.50
British Columbia
25.93
-16.10
Canadian Economic and Emissions Model for Agriculture: Report 1
B-1
Appendix C: Results of Regression
Analysis
As noted in Chapter 4, an attempt was made to find a conversion factor to convert various
CRAM cost input data into physical quantities.
C.1 Results for Fuel Cost
The dependent variable for this analysis was quantity of fuel per acre (QFUEL), as reported by
Rutherford and Gimby (1988). The independent variables included: fuel cost (COSTFUEL), and
two binary variables, one each for dark brown (BYDB) and brown soil (BYBR) zones. Thus,
the black soil zone was used as the base. The results are summarized as follows (with
standard error of estimate in parentheses):
Q FUEL = 47.37 - 1.498 COST FUEL - 7.569 BYDB - 8.726 BYBR
(-16.78)
(-1.50)
(-1.525)
(-1.557)
R 2 = 0.208
n = 16
(C.1)
F = 1.05
The probability of the F-value suggesting that the regression effect does exist was 40.6%.
Thus, it was concluded that the quantities and cost from the two sources are not consistent
with each other, and therefore, this analysis should not be used in developing a conversion
factor for fuel costs in CRAM into physical quantities.
C.2 Results for the Herbicide Costs
This analysis was exactly the same as for fuel costs, except that the dependent variable was
the cost of chemicals per acre (QHERB). The only change in the independent variables was that
cost of herbicides (COSTHERB) was used. The following results were obtained (with standard
error of estimate in parentheses):
Canadian Economic and Emissions Model for Agriculture: Report 1
C-1
Appendix C
Q HERB = 1.037 - 0.005 COST HERB - 0.193 BYDB +
(-2.375) (-0.350)
(-0.661)
R 2 = 0.168
n = 16
0.273 BYBR
(-0.816)
(C.2)
F = 0.808
Results obtained do not support the hypothesis of a relationship between quantity of
herbicides uses and the herbicide cost estimates in CRAM. Even the differences in the level
of herbicide quantity by soil type was not found to be statistically different from zero.
C.3
Results for Fertilizer Costs
This analysis was exactly the same as for fuel costs, except that the dependent variable was
the fertilizer cost per acre (QFERT), which was obtained from Rutherford and Gimby (1988).
The only change in the independent variables list was that cost of fertilizer (COSTFERT) was
used. The following results were obtained (with standard error of estimate in parentheses):
Q FERT = 17.87 + 3.302 COST FERT - 7.181 BYDB + 4.624 BYBR
(0.812) (5.498)
(-0.361)
(0.199)
R 2 = 0.741
n = 16
(C.3)
F = 11.42
The hypothesis related to relationship between fertilizer quantities and their cost (as reported
in CRAM) was accepted at a probability of 1%. However, in order to keep consistency in
methodology, and because results for fuel and herbicides costs were poor, using CRAM cost
for estimating respective quantities of fertilizer was not used.
C-2
Canadian Economic and Emissions Model for Agriculture: Report 1
Appendix D: Details on Selected Crop
Inputs by Provinces
The emissions of greenhouse gases from various crops in different regions are affected by the
assumptions made with respect to the level of farm input used in the regions. Three inputs
that are noteworthy in this respects are: fertilizer, fuel, and herbicides. The assumptions
made with respect to their levels are shown in Table D.1 for fertilizer, in Table D.2 for fuel,
and in Table D.3 for herbicides.
Canadian Economic and Emissions Model for Agriculture: Report 1
D-1
Appendix D
Table D.1: Levels of Fertilizer Used in the Production, by Crop and Regions
Saskatchewan lbs acre-1
Crop
Rotation
Brown Soil
Zone
Dark Brown
Soil Zone
Black Soil
Zone
Manitoba
lbs acre-1
Ontario
kg ha-1
Stubble
45
50
60
70
251
Fallow
20
25
30
70
251
Stubble
45
50
60
70
230
Fallow
20
25
35
80
230
457
512
Barley
Canola
Corn
Stubble
45
50
50
50
-
Fallow
20
25
25
25
-
Stubble
45
50
50
70
-
Fallow
20
25
25
70
-
Field Peas
15
15
20
-
2
Hay
20
20
20
20
18
Stubble
10
15
20
-
-
Fallow
4
5
7
-
-
Stubble
45
45
60
60
-
Fallow
20
20
30
60
-
Pastures
90
100
120
140
502
Potatoes
-
-
-
-
230
Soybeans
-
-
-
-
2
Summerfallow
0
0
0
0
-
Stubble
45
50
60
70
154
Fallow
20
25
30
-
-S
Durum
Flaxseed
Lentils
Oats
Wheat
D-2
Canadian Economic and Emissions Model for Agriculture: Report 1
Details on Selected Crop Inputs by Provinces
Table D.2: Fuel Use (in litres per acre) for Crops, by Regions
Saskatchewan
Crop
Rotation
Manitoba
Ontario
20
30
28
17
17
30
-
21
21
21
30
28
18
18
18
30
-
-
-
-
49
49
Stubble
20
20
20
17
-
Fallow
17
17
17
17
-
Stubble
22
22
22
30
-
Fallow
19
19
19
30
-
Field Peas
22
22
22
36
32
Hay
20
20
20
20
18
Stubble
22
22
22
32
-
Fallow
19
19
19
32
-
Stubble
20
20
20
30
-
Fallow
17
17
17
30
-
Pastures
40
40
40
60
56
Potatoes
-
-
-
-
28
Soybeans
-
-
-
-
27
10
10
10
10
-
Stubble
20
20
20
30
28
Fallow
17
17
17
30
-
Brown Soil
Zone
Dark
Brown Soil
Zone
Black Soil
Zone
Stubble
20
20
Fallow
17
Stubble
Fallow
Barley
Canola
Corn
Durum
Flaxseed
Lentils
Oats
Summerfallow
Wheat
Canadian Economic and Emissions Model for Agriculture: Report 1
D-3
Appendix D
Table D.3: Herbicide Cost per Acre, by Crop and Regions (All costs are in dollar per
acre)
Saskatchewan
Crop
Rotation
Brown Soil
Zone
Dark Brown
Soil Zone
Black Soil
Zone
Manitoba
Ontario
Stubble
8.46
11.41
11.41
20.00
30.50
Fallow
8.18
11.41
11.41
20.00
-
Stubble
15.71
17.06
15.71
29.00
41.00
Fallow
15.71
15.71
15.71
29.00
-
-
-
-
29.44
29.44
Stubble
8.46
11.98
11.98
11.98
-
Fallow
8.46
11.98
11.98
11.98
-
Stubble
17.97
17.97
17.97
22.50
-
Fallow
11.97
11.97
11.97
22.50
-
Field Peas
22.50
22.50
26.65
-
35.10
Hay
15.10
15.10
15.10
15.10
13.50
Stubble
39.11
39.11
39.11
31.50
-
Fallow
39.11
39.11
39.11
31.50
-
Stubble
4.95
4.95
4.95
4.95
-
Fallow
4.95
4.95
4.95
4.95
-
Pastures
16.90
22.80
22.80
40.00
63.00
Potatoes
-
-
-
-
41.00
Soybeans
-
-
-
-
32.50
2.86
2.86
2.86
2.86
-
8.46
11.98
11.98
20.00
24.00
Barley
Canola
Corn
Durum
Flaxseed
Lentils
Oats
Summerfallow
Stubble
Wheat
Fallow
D-4
8.46
11.98
11.98
20.00
-
Canadian Economic and Emissions Model for Agriculture: Report 1
Appendix E: Emissions of Greenhouse
Gases by Provinces and Activities
Table E.1: Total Emissions of Greenhouse Gases, British Columbia, kilo tonnes per
year, by GHG Activities, 1994
Activity
CO2
CH4
N2O
CO2-Eqv.
CROP PRODUCTION
Biomass Burning
0
0
-
1.27
Crop Residues
0
0
0.70
216.57
Fertilizer
0
0
0.07
20.52
Use of Manure
0
0
0.42
126.86
Fossil Fuel
161.10
0
0.01
165.44
Chemicals
1.14
0
0
1.14
0
0
0.25
76.60
Soil Organic Matter
172.9
0
0
172.92
Crop Total
335.5
0
1.45
784.32
0
23.84
0
500.7
37.34
0
0
37.34
0
25.9
0.26
481.41
37.34
49.74
0.26
1,162.12
372.47
49.74
1.71
1,946.44
Nitrogen Fixing Crops
LIVESTOCK PRODUCTION
Raising Livestock
Livestock Management
Animal Excr. / Wastes
Livestock Total
Grand total
-Quantity less than 0.005 kt.
Canadian Economic and Emissions Model for Agriculture: Report 1
E-1
Appendix E
Table E.2: Total Emissions of Greenhouse Gases, Alberta, kilo tonnes per year, by
GHG Activities, 1994
Activity
CO2
CH4
N2O
CO2-Eqv.
CROP PRODUCTION
Biomass Burning
0
0
0.11
33.80
Crop Residues
0
0
7.86
2,436.20
Fertilizer
0
0
1.16
359.72
Fossil Fuel
2,010.56
0
0.18
2,065.42
Chemicals
18.56
0
0
18.56
0
0
1.31
405.85
Soil Organic Matter
5,202.81
0
0
5 202.81
Crop Total
7,231.93
0.00
10.98
10,635.26
0
95.61
0
2,007.84
330.95
0
0
330.95
0
157.70
1.21
3,686.54
330.95
253.33
1.21
6,025.33
7,562.88
253.33
12.19
16,660.58
Nitrogen Fixing Crops
LIVESTOCK PRODUCTION
Raising Livestock
Livestock Management
Animal Excr./ Wastes
Livestock Total
Grand total
E-2
Canadian Economic and Emissions Model for Agriculture: Report 1
Emissions of Greenhouse Gases by Provinces
Table E.3: Total Emissions of Greenhouse Gases, Saskatchewan, kilo tonnes per year,
by GHG Activities, 1994
Activity
CO2
CH4
N2O
CO2-Eqv.
CROP PRODUCTION
Biomass Burning
0
0
0.18
56.49
Crop Residues
0
0
9.93
3,077.28
Fertilizer
0
0
1.80
556.74
Fossil Fuel
2,708.35
0
0.24
2,782.27
Chemicals
22.72
0
0
22.72
0
0
1.49
463.23
Soil Organic Matter
3,007.85
0
0
3,007.85
Crop Total
5,738.92
0
13.77
10,007.30
0
52.24
0
1,096.94
142.68
0
0
142.68
0
71.75
0.62
1,698.83
Livestock Total
1,020.43
161.20
1.49
3,195.93
Grand total
5,881.60
123.98
14.39
12,945.75
Nitrogen Fixing Crops
LIVESTOCK PRODUCTION
Raising Livestock
Livestock Management
Animal Excr./Wastes
Canadian Economic and Emissions Model for Agriculture: Report 1
E-3
Appendix E
Table E.4: Total Emissions of Greenhouse Gases, Manitoba, kilo tonnes per year, by
GHG Activities, 1994
Activity
CO2
CH4
N2O
CO2-Eqv.
CROP PRODUCTION
Biomass Burning
0
0
0.06
17.45
Crop Residues
0
0
3.24
1004.79
Fertilizer
0
0
0.92
283.68
Fossil Fuel
1,212.45
0
0.11
1,245.39
Chemicals
17.88
0
0
17.88
0
0
0.57
175.45
Soil Organic Matter
2,068.30
0
0
2,068.30
Crop Total
3,298.63
0
5.09
4,875.61
0
41.93
0
880.6
147.42
0
0
147.42
0
134.12
0.58
2,997.50
147.42
176.06
0.58
4,025.52
3,446.05
176.06
5.67
8,901.13
Nitrogen Fixing Crops
LIVESTOCK PRODUCTION
Raising Livestock
Livestock Management
Animal Excr./Wastes
Livestock Total
Grand total
E-4
Canadian Economic and Emissions Model for Agriculture: Report 1
Emissions of Greenhouse Gases by Provinces
Table E.5: Total Emissions of Greenhouse Gases, Ontario, kilo tonnes per year, by
GHG Activities, 1994
Activity
CO2
CH4
N2O
CO2-Eqv.
CROP PRODUCTION
Biomass Burning
0
0
0.01
2.85
Crop Residues
0
0
1.68
520.77
Fertilizer
0
0
2.03
627.75
Fossil Fuel
679.21
0
0.06
697.68
Chemicals
8.56
0
0
8.56
0
0
0.09
28.77
34.61
0
0
34.61
722.38
0
5.05
2,287.38
0
108.44
0
2,277.27
345.34
0
0
345.34
0
256.11
1.36
5,801.33
345.34
364.56
1.36
8,423.94
1,067.72
364.56
6.41
10,711.32
Nitrogen Fixing Crops
Soil Organic Matter
Crop Total
LIVESTOCK PRODUCTION
Raising Livestock
Livestock Management
Animal Excr./Wastes
Livestock Total
Grand total
Canadian Economic and Emissions Model for Agriculture: Report 1
E-5
Table E.6: Total Emissions of Greenhouse Gases, Quebec, kilo tonnes per year, by
GHG Activities, 1994
Activity
CO2
CH4
N2O
CO2-Eqv.
CROP PRODUCTION
Biomass Burning
0
0
0.01
1.86
Crop Residues
0
0
0.65
197.01
Fertilizer
0
0
1.03
318.06
Fossil Fuel
311.05
0
0.03
319.51
Chemicals
3.88
0
0
3.88
0
0
0.14
42.63
Soil Organic Matter
171.14
0
0
171.14
Crop Total
486.07
0
2.85
1,371.02
0
104.10
0
104.05
342.58
0
0
556.73
0
270.00
1.35
6,086.85
Livestock Total
342.58
374.00
1.35
8,614.55
Grand total
828.65
374.00
4.20
9 985.57
Nitrogen Fixing Crops
LIVESTOCK PRODUCTION
Raising Livestock
Livestock Management
Animal Excr./Wastes
Emissions of Greenhouse Gases by Provinces
Table E.7: Total Emissions of Greenhouse Gases, New Brunswick, kilo tonnes per
year, by GHG Activities, 1994
Activity
CO2
CH4
N2O
CO2-Eqv.
CROP PRODUCTION
Biomass Burning
0
0
-
0.16
Crop Residues
0
0
0.11
14.23
Fertilizer
0
0
0.11
21.95
Fossil Fuel
24.85
0
-
25.53
Chemicals
0.34
0
0
0.34
0
0
0
3.78
(49.80)
0
0
-47.75
-22.6
0
0.22
46.01
0
4.72
0
99.14
15.44
0
0
15.44
0
7.71
0.10
178.42
Livestock Total
15.44
12.40
0.10
292.99
Grand total
-7.13
12.40
0.27
339.01
Nitrogen Fixing Crops
Soil Organic Matter
Crop Total
LIVESTOCK PRODUCTION
Raising Livestock
Livestock Management
Animal Waste
- Quantity less than 0.005 kt.
Canadian Economic and Emissions Model for Agriculture: Report 1
E-7
Appendix E
Table E.8: Total Emissions of Greenhouse Gases, Prince Edward Island, kilo tonnes
per year, by GHG Activities, 1994
Activity
CO2
CH4
N2O
CO2-Eqv.
CROP PRODUCTION
Biomass Burning
0
0
-
0.25
Crop Residue
0
0
0.05
15.28
Fertilizer
0
0
0.08
25.55
Fossil Fuel
29.46
0
-
30.25
Chemicals
0.42
0
0
0.42
0
0
0.01
2.50
Soil Organic Matter
51.40
0
0
51.40
Crop Total
81.28
0
0.15
128.52
0
3.83
0
80.4
18.47
0
0
18.47
0
9.71
0.05
220.08
Livestock Total
18.47
13.54
0.05
318.96
Grand total
99.74
13.54
0.20
447.48
Nitrogen Fixing Crops
LIVESTOCK PRODUCTION
Raising Livestock
Livestock Management
Animal Waste
- Quantity less than 0.005 kt.
E-8
Canadian Economic and Emissions Model for Agriculture: Report 1
Emissions of Greenhouse Gases by Provinces
Table E.9: Total Emissions of Greenhouse Gases, Nova Scotia, kilo tonnes per year, by
GHG Activities, 1994
Activity
CO2
CH4
N2O
CO2-Eqv.
CROP PRODUCTION
Biomass Burning
0
0
-
0.08
Crop Residues
0
0
0.04
12.25
Fertilizer
0
0
0.06
18.07
Fossil Fuel
20.08
0
-
20.63
Chemicals
0.25
0
0
0.25
0
0
0.01
4.25
Soil Organic Matter
-27.6
0
0
-27.59
Crop Total
-7.26
0
0.23
64.58
0
5.67
0
119.15
24.64
0
0
24.64
0
12.48
0.07
284.04
Livestock Total
24.64
18.16
0.07
427.83
Grand total
17.38
18.16
0.30
492.41
Nitrogen Fixing Crops
LIVESTOCK PRODUCTION
Raising Livestock
Livestock Management
Animal Excr./Wastes
- Quantity less than 0.005 kt.
Canadian Economic and Emissions Model for Agriculture: Report 1
E-9
Appendix E
Table E.10: Total Emissions of Greenhouse Gases, Newfoundland, kilo tonnes per
year, by GHG Activities, 1994
Activity
CO2
CH4
N2O
CO2-Eqv.
CROP PRODUCTION
Biomass Burning
0
0
-
0.01
Crop Residues
0
0
-
0.71
Fertilizer
0
0
0.06
18.07
Fossil Fuel
2.29
0
-
2.36
Chemicals
0.03
0
0
0.03
0
0
-
0.31
Soil Organic Matter
-2.95
0
0
-2.95
Crop Total
-0.63
0
0.06
16.58
0
0.76
0
15.94
2.19
0
0
2.19
0
1.62
0.01
36.91
Livestock Total
2.19
2.38
0.01
55.05
Grand total
1.56
2.38
0.07
71.63
Nitrogen Fixing Crops
LIVESTOCK PRODUCTION
Raising Livestock
Livestock Management
Animal Excr./Wastes
- Quantity less than 0.005 kt.
E-10
Canadian Economic and Emissions Model for Agriculture: Report 1