Population and Consumption
• Population demographics
• Why are people having large families?
• Ecological impacts of human populations
• Global Carrying Capacity, Ecological Footprints, and the
I = PAT Equation
• What can we do??
Population Demographics
Land belongs to one large family, few of whom are alive,
many of whom are dead, countless of whom are unborn.
—Dr. RS Mongoba
Global Population Growth
Demographic Transition
Growth in Less Developed Countries
Why are people having large families?
Large families are a rational strategy for survival in many
parts of the world. Children’s labor is an important part of the economy
in peasant communities in Asia, Africa, and Latin America.
The risk and insecurity that patriarchy imposes on women
represent a powerful systemic incentive for high fertility…The best risk
insurance for women…is to produce sons, as many and as soon as possible.
—conclusions
of a demographic study conducted in Bangladesh
Women and girls are the subjects, not the objects, of
population policies and have the right to determine whether, when, why,
with whom, and how to express their sexuality; they have the right to
determine when and whom to marry, they have the right and responsibility
to decide whether, how, and when to have children.
—US policy recommendations
to the UN ICPD Secretariat
Increased Desire for Smaller Families
Rising Contraceptive Use in Developing Countries
Contraceptive Methods: Developing Countries vs. Developed
Countries
The Potential Demand for Family Planning
Women's Rights and Population Growth
The population problem is integrally linked with justice
for women in particular… Advancing gender equity, through reversing the
various social and economic handicaps that make women voiceless and powerless,
may also be one of the best ways for saving the environment… The voice
of women is critically important for the world’s future—not just for women’s
future.
—Amartya Sen
The educational level of women is the best predictor of
fertility and contraceptive use, even more important than income level.
Do you think reproduction is a woman’s right?
Are there conditions under which reproductive rights can or should be
restricted?
Ecological Impacts of Human Populations
Ecological Impacts of Populations are related to…
• Growth Rates
• Population Densities
• Migration
• Distribution of population between rural and urban areas
• Fragility and diversity of local ecosystems
• Consumption patterns
Causes of Population-based (Malthusian)
Resource Degradation
• Over-grazing
• Deforestation
• Agricultural Mismanagement
Gross inequities in the distribution of land are critically
important in many less developed nations where the majority of the population
lives in rural areas.
Political carrying capacity:
the limited capacity of the environment to sustain inequality
and injustice
Technological-and-Consumption-Based Resource Degradation
• Resource harvest and extraction around the world for consumption
in the developed nations create numerous ecological and social impacts.
• Waste generation and pollution are impacts that are closely
associated with highly consumptive populations.
Consumption
Physics --Consumption is the transformation of matter and energy
into forms with greater entropy.
Economics --Consumption is spending on goods and services.
Ecology --Consumption is gaining energy and nutrients by eating
plants and the consumers of plants.
Sociology --Consumption is a status symbol where people use their
income to increase their status by purchasing goods and services.
Consumption:
the human transformation of materials and energy, a transformation
that can make those materials and energy less available for future use
and that can negatively impact natural systems.
The Wealthiest 20%…
• Consumes 85% of all processed wood products
• Consumes 75% of energy resources
• Produces 90% of CFCs
• 65% of carbon dioxide emissions
Do you think that it’s fair that wealthy nations use more
resources per capita than poor nations?
Do you think resource consumption is a right? Are there ethical limits
to consumption?
Global Carrying Capacity, Ecological Footprints,
and the I = PAT Equation
Carrying capacity :
the number of organisms that an ecosystem can support indefinitely
How will know when or if we have “overshot” the Earth’s
carrying capacity?
Ecological Footprint:
A measure of how much of the Earth is being used for the production
of all the resources a given population consumes and for the assimilation
of all its waste, using current technology.
The problem with land is that they stopped making
it some time ago.
-Mark Twain
“Fair Earthshare”:
the average amount of ecologically productive land and sea available globally
per person
Ten billion [people] with everyone following an American diet…would
require 9 billion tons of grain, the harvest of more than four planets
at the Earth’s current output levels…
—State of the World 1999
Ecological Footprints of Nations
World
2.2 hectares (ha)
U.S.A.
9.6 ha
Canada
7.2 ha
Germany
4.6 ha
Israel 3.5
ha
China
1.4 ha
India 1.0
ha
Pakistan
0.9 ha
Ethiopia
0.7 ha
The
I = PAT Equation
I = Total Human Impact on Earth
P = Population
A = Affluence
(Gross Domestic Product per capita)
T = Technology
(Technological impact per good/service)
Affluence (A):
- An economic measure of buying power, NOT a physical measure
of consumption.
-The income produced by workers, the economic muscle that the population
can exercise.
-A is measured as the gross national product per capita.
I = PACT
where C = intensity of use (materials/energy consumed per GDP)
P is driven by parents;
A is driven by workers;
C is driven by consumers; and
T is driven by producers.
Technology (T):
environmental impact per produced good/service
The Technological Paradox:
Technology is both the the source and
the remedy for human-caused environmental impact.
Industry
• Largest transformer (consumer) of material resources and
energy
• Mobilizes roughly 20 billion tons of fossil fuels, minerals,
and renewable natural resources per year
• Produces more than 40 billion tons of wastes per year
Technological Strategies for Reducing Human Impact
• “Clean-up” technologies
• Pollution prevention
• Increases in resource efficiency
…continuing growth in material consumption—the number
of cars and air conditioners, the amount of paper used, and the like—will
eventually overwhelm gains in efficiency, causing total resource use (and
all the corresponding environmental damage) to rise…
-Lester Brown, Worldwatch Institute
Do you think there really is a global carrying capacity
for humans?
Do you think the I= PAT equation is leaving anything important out?
What can we do?
Reduce Consumption
• Separate out more damaging forms of consumption and shift
to less harmful forms
• Shrink the amount of environmentally damaging energy and
materials used per unit of consumption
• Promote voluntary simplicity
• Consider replacing the income tax with a consumption tax
• Include an understanding of consumption patterns in our
environmental policy
Reduce Human Impact
P
• Have fewer children
• Support gender equality and women’s reproductive rights
A
• Reduce personal consumption
• Choose least damaging products and services
T
• Develop new low-impact technologies
References
Chambers N., C. Simons, and M. Wackernagel. 2000. Sharing
Nature’s Interest.
Ehrlich P. 1968. The Population Bomb.
Ehrlich P. and A. Ehrlich. 1990. The Population Explosion.
Simon J. 1981, 1996. The Ultimate Resource.
Simon J. and H. Kahn. 1984. The Resourceful Earth.
Wackernagel M. and W. Rees. 1996. Our Ecological Footprint.
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