the rate of growth is now linear, but we are adding the equivalent of 2.5 canadas every year
TRANSCRIPT
HumanPopulati
onGrowth
Factorsand
Consequences
The Story So Far0
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World Population - AD 1 to 2050
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The Story So Far
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Annual World Population Growth (1910 to Present)
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Green Revolution (1943-1980) China's Great Leap Forward (1958-1961)
The rate of growth is now linear, but we are adding the equivalent of 2.5 Canadas every year.
The Story So Far
If this trend holds, global population could peak in 2030 at 7.6 billion.
Why Do Populations Grow?
• Perceived needPhysical (more hands)Cultural (family size, national growth)
• OpportunityLiving spaceResources (food, energy, raw materials)Improvements in health
Why Does PopulationGrowth Slow?
• Loss of perceived needMechanizationCultural changes (choices or imposed)
• Loss of opportunityOvercrowdingLack of resources (food, energy, raw
materials)• Diseases• Wars and genocides
Most Theories of Population Growth aren’t Predictive
The DTM is an observation of past behaviour, not a predictive theory.No universal explanation has been advanced for the decline in birth rates.
Energy and Population
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Population and Energy Consumption (USA)
Population Energy Consumption
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The Ecological View
I = PATIMPACT = Population x Affluence x
Technology
Humanity’s Impact on the Biosphere
ImPAcT
ImPAcT
Carrying Capacity
Carrying Capacity
• “The population of a species that the environment can sustain indefinitely.”What does “indefinitely” mean?What about quality of life?What about other species?
• Hard to determine human carrying capacity.
Overshoot
Humanity is about 40% into overshoot.
Evidence of Overshoot
Unlike carrying capacity, overshoot is easy to determine.
Evidence of Overshoot
The Ghost of Thomas Malthus -
Food Production• Do increases in food production
follow or precede population growth?• Politics and economics say they
follow growth, ecology says they drive growth.
Asking,“How will we find enough food to feed this growing population?”
is like asking,“How will we find enough fuel to feed this growing fire?”
Food, the Human Constant
• We each need 2500 kcal/day to live.This requires a constant amount of
resourcesThis produces a constant environmental
impactAll other impacts can be reduced, but
the impact of food production remains relatively constant.
75 million new people every year adds an ecological footprint of 2 million square kilometers (equal to the biocapacity of a new Canada every three years).
We are already in overshoot…
So, What Do We Do About It?
• We do not have a knowledge gap – we have plenty of knowledge and technology.“If you have dug yourself into a hole, switching to
a more efficient shovel won’t help.”
• All the problems have a common root – our sense of Man being separate from Nature.
• Our problem is the story we tell ourselves about who we are.
• We cannot change the cultural story from the top down, only from the bottom up.
The Change is Already Under Way
• The change in our cultural story is happening one person at a time - every time someone changes a light bulb, the light bulb changes them.
• The evidence for this change is the unexpected drop in fertility rates in the last 20 years.
• The drop in TFR has been driven by individual choices, not by policies or resource constraints.
• Humanity has a big problem, it will take a while to turn around. We may have just enough time…
Choices• Everything we do is a choice.• Every choice we make affects
the future.• What choices are you making?
Suggestions• Promote population reduction• Promote lower-tech solutions• Prevent urban sprawl into rural
areas.
Contact
This presentation has been prepared by
Paul ChefurkaOttawa, Canada
Email: [email protected]: http://www.paulchefurka.ca
© September, 2010
Public Domain: This work may be reproduced in whole or in part in any manner and for any purpose whatsoever, with no restrictions.