Population and the Environment
Fernando Riosmena
Department of Geography
GEOG-2412
Our time on Earth in a cosmic scale
Big Bang
January 1
Origin of life on Earth
~ September 25
December 31st:
First humans
~ 10:30 p.m.
Invention of agriculture
11:59:20 p.m.
Hammurabic legal codes in Babylon; Middle Kingdom in Egypt
11:59:52 p.m.
Bronze metallurgy; Mycenaean culture; Trojan War; Olmec culture; invention of the compass
11:59:53 p.m.
Iron metallurgy; First Assyrian Empire; Kingdom of Israel; founding of Carthage by Phoenicia
11:59:54 p.m.
Asokan India; Ch'in Dynasty China; Periclean Athens; birth of Buddha
11:59:55 p.m.
Euclidean geometry; Archimedean physics; Ptolemaic astronomy; Roman Empire; birth of Christ
11:59:56 p.m.
Zero and decimals invented in Indian arithmetic; Rome falls; Moslem conquests
11:59:57 p.m.
Mayan civilization; Sung Dynasty China; Byzantine empire; Mongol invasion; Crusades
11:59:58 p.m.
Renaissance in Europe; voyages of discovery from Europe and from Ming Dynasty China; emergence
of the experimental method in science
11:59:59 p.m.
Widespread development of science and technology; emergence of global culture; acquisition of the
means of self-destruction of the human species; first steps in spacecraft planetary exploration and
the search of extraterrestrial intelligence
Now: The first second of
New Year's Day
Source: Originally taken from Carl Sagan’s The Dragons of Eden
http://admiralty.pacific.net.hk/~paulchui/cosmic.html
Unprecedented growth throughout history (but
“few” doublings)
Source: McFalls, J.A. 2007.
“Population: A Lively
Introduction”. Population
Bulletin 62(1):1-31.
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The future of course may bring further challenges in
terms of sustainability
Source: Weeks,
Fig 2.2.
The Demographic Transition implies going from
high to low mortality, fertility. In-between, sizable
growth due to lag between mortality and fertility
decline. Many places still “undergoing” it.
Source: Fig. 3.2. in Weeks, 2005. Population.
With (better) projections, another doubling,
unlikely during this Century
Source: Lutz, W. W. Sanderson, and S. Scherbov. 1997 “Doubling of Population Unlikely” Letters to Nature.
387:803-805.
2
Asynchronous demographic change will imply shifts
in the share of the World’s population by region.
Source: McFalls, J.A. 2007.
“Population: A Lively
Introduction”. Population
Bulletin 62(1):1-31.
Impacts of population on the Environment

Population as a cause of environmental “change”


As opposed to environmental influence on population dynamics
Obviously, we have deeply transformed our environment

Though not the only ones doing so, our impact much deeper

Interest in extent of past and future environmental changes

Generally through the lens of “IPAT” (or IPCT)



I=PxAxT
P may be size, density, etc.
T = Tr x Tw x S (environmental susceptibility)
Different population regime, consumption patters,
and environmental footprint across different
technological regimes
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Understanding impacts through the pressure-stateresponse model
SOCIETAL RESPONSE
PRESSURE
Population
Consumption
Technology
STATE OF
ENVIRONMENT
Pollution
Degradation
Depletion
Resource use
Waste output
FEEDBACK
Scarcity
Hazard
Loss of amenity
Price shift
Changes in
Behavior
Culture
Technology
Resource management
Policy measures
Regulation
Taxation
Subsidy
FILTERS
Science
Monitoring
Political/legal systems
Market/property systems
For instance, (Urban) Heat Island Effect
http://earthobservatory.nasa.gov/Features/GreenRoof/
UIH effect creates sizable variation in temperature
across space, particularly at night.
What kind of prevention, mitigation strategies are out
there?
http://www.climatechangefacts.info/Today-Global-Climate-Change-Status-and-Trends.html
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Views on population and the environment

Malthusian/Neo-malthusian




Cornucopian/Market-response



Paul Ehrlich’s Population Bomb
Degradation, resource loss if business as usual in pop growth
Plenty of “negative externalities” in population growth
Julian Simon
Market mechanisms have/will help us adjust behavior
Distributionist view, a third, ~middle view


Marxist origins
Less attention in many policy circles
The original Malthusian reasoning was tied to the
idea that food production (or other resources)
could not grow at the same pace as the population
Malthusian, Cornucopian views may dominate…
depending on the resource?
Source: Harrison, P. and F. Pearce (2000). AAAS atlas of population & environment. Univ of California Press.
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Grim scenarios re P x A x T and greenhouse gas
emissions (but do not conflate P x A x T with P)
Source: Harrison, P. and F. Pearce (2000). AAAS atlas of population & environment. Univ of California Press.
Population vs. affluence, consumption: United States
Source: Menzal, P.
Material World
Population vs. affluence, consumption: Thailand, Mali
Source: Menzal, P. Material World
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World Population in 2006
The size of each territory shows the relative proportion
of the world's population living there.
Energy consumption in 2006
Population trends and various estimates of carrying
capacity (under a variety of assumptions), illustrating
the impact of all P, A/C, & T
Source: Cohen, J.E. 1997 “Population, Economics, Environment, and Culture: an Introduction to Human
Carrying Capacity”. Journal of Applied Ecology 34:1325-1333.
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LOG10 population density (no km-2)
Carrying capacity (with near-zero technological
expertise) well below today’s population. Which
illustrates the relevance of technological progress…
LOG10 body mass (kg)
Source: Cohen, J.E. 1997 “Population, Economics, Environment, and Culture: an Introduction to Human
Carrying Capacity”. Journal of Applied Ecology 34:1325-1333.
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