Estimated Greenhouse Gas Emissions
Zweck – Blyth, SA.
These figures have been calculated using the Dairy Greenhouse Gas Abatement Strategy or
DGAS. The DGAS calculator was developed to estimate the greenhouse gas (GHG) emissions
for Australian dairy farms, by using methodologies and emission factors that are reflective of
Australian conditions. The calculator can be downloaded at www.dairyingfortomorrow.com
A great deal of research is underway within the Australian dairy industry to decrease the
release of methane and nitrous oxide from farming systems.
Baseline Contributors to Total Em issions
4%
29%
11%
56%
What does DGAS estimate?
DGAS estimates four sources of GHGs. These are:
 Methane (CH4) respired by stock as part of the digestive process (enteric
fermentation) and through manure management;
 Nitrous oxide (N2O) is emitted with the management of animal waste and from
nitrogen fertilisers. These nitrous oxide emissions are further broken down into
direct (occurring on your farm) and indirect (loss to the environment through
leaching/runoff and volatilisation);
 Carbon dioxide (CO2) from the consumption of electricity and fuels;
 Carbon dioxide (CO2) associated with the production of key farm inputs such as
grains/concentrates, hay and silage, and fertilisers (pre-farm embedded)
P re-farm
On-farm CO2
On-farm CH4
On-farm N2O
Total farm emissions
Pre-farm (t/t MS)
On-farm CO2 (t/t MS)
On-farm CH4 (t/t MS)
On-farm N2O (t/t MS)
1894
.65
1.77
8.7
4.58
Tree Plantings (t/t MS)
-0.0
Total Farm (t/t MS)
15.7
(t CO2e/farm)
Emissions per cow eq. (394)
Emissions per ha (669)
4.8
2.8
Greenhouse Gas Emissions
9
8
What can we do to reduce Greenhouse Gas emissions on dairy farms?
Production improvement options and best management practices are most often linked to
greenhouse gas emissions reduction. At present, well managed farms have few options to
reduce emissions without significant changes to their farming or feeding system. With no
formal incentive in place to reduce GHG emissions, Australian farmers should consider
emissions reduction options that lead to productivity gains or have cost benefits. Any option
should be looked at within the whole farm system.
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Recent data from DPI Victoria indicates that GHG emissions on Victorian dairy farms range
between 7.2 T CO2e per tonne of milk solids to 15.4T with the average being 10.2T CO2e per
tonnes of milk solids (DPI Farm Monitor Project 2009/10). Only a limited numbers of farms in
SA have participated in DGAS at this time but emissions have ranged from 12.2 – 15.9 tonnes
CO2e per tonne of milk solids with an average of 14.1 tonnes CO2e per tonne of milk solids.
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What sort of Greenhouse Gas emissions can we expect on Australian dairy farms?
t CO2-e/t MS
7
CH4 and N2O have a higher potential to warm the environment, compared to CO2, all emissions
are converted into carbon dioxide equivalents (CO2e). DGAS estimates the CO2e emissions
both as a total figure (tonnes of CO2e) and as a milk intensity figure by dividing total emissions
by annual milk production (t CO2e per tonne of milksolids). This allows results to be compared
between farms, irrespective of differences between farms such as milking herd size and level
of milk production.
This information sheet was prepared by Monique White, Dairying for Tomorrow SA, based on data
collected by Sam Acheson and the original sheet by Gillian Hayman, Dairying for Tomorrow Coordinator
Gippsland. It was prepared for the Future Ready Dairy Systems project funded by The Australian
Department of Agriculture, Forestry & Fisheries and Dairy Australia. April 2011.