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Population, Resources, Environment. Population boom. falling death rates and longer lives from better nutrition, sanitary conditions, and healthcare. Demographic Transition. After initial population explosion, birth rates drop in more urban affluent societies. Population momentum.
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Population boom • falling death rates and longer lives from better nutrition, sanitary conditions, and healthcare
Demographic Transition • After initial population explosion, birth rates drop in more urban affluent societies
Population momentum • fast growing societies continue to grow, since many enter reproductive years
Population policy • “development = population control” • family planning programs • US retreating under Bush—abstinence only • female literacy/education • China’s experiment • 1979 one-child policy • 250 million fewer births • a success?
Problems of population slowing • growth of dependent portion of population • will be especially acute in developing world • It took 50 ys for US average age to increase 5 ys—Mexico’s will go up 20.
Problems of population growth • polluting and exhausting resources • Example: Rwanda • is the problem population, or unsustainable practices? • example--eating higher on the food chain
water • US water used for glass of milk, burger, small steak? • 200 gallons • 800 gallons • 1300 gallons • depleting aquifers, falling production
Soil degradation and desertification • “New Lands”--Aral Sea • Local life expectancy from 65 to 51 • Highest rate of cancer of esophagus in world • http://www.films.com/id/12468/Killing_the_Aral_Sea_Catastrophe_by_Design.htm
Rainforest destruction • From logging, slash and burn, fuel wood, cash crops, and ranching • http://www.voanews.com/english/2006-06-09-voa48.cfm
Soil erosion • 99% of world’s food from soil, but losing soil—25 m. acres per year • from slash and burn and unsustainable farming, logging, and grazing • Lost to water, wind
Some Solutions • Technology • Green Revolution? • Problems: needs expensive inputs, and more water • GM?
A special case: the sea • problems of stewardship of a collective good • the failure of international agreements to protect fisheries • 1995 wild fish harvest peaked, despite more intensive fishing • Aquaculture fastest growing animal husbandry
oil • Hubberts “peak oil” • Collapse of petro-civilization? • Julian Simon and the Cornucopians
Pollution • The development-pollution or Kuznets curve
A possible exception: • global warming or “greenhouse effect”
What is the Greenhouse effect? • CO2 and other gasses trap sun’s rays
Consequences • raising sea levels, causing droughts and storms, and disrupting ecosystems, crop productivity, ocean acidification • self-sustaining processes: • melting polar ice-caps cool less and reflect less light/heat • thawing permafrost releases more g.h. gasses
Kyoto • 1997 Kyoto Protocols, formally in effect since 2004 • U.S. and other developed countries were to reduce g.h. gasses below 1990 levels by 2012 • 1997-’01 Senate fails to ratify the treaty • 2001 Bush dismisses Kyoto Protocols • cites insufficient evidence, too great costs • Developing countries, like China and India exempted
What can be done? • Gas tax • cleaner and alternative forms of energy • California’s “Pavley Law”, and beyond • Northeast states’ cap and trade • Ethanol—and Brazil’s cellulosic ethanol • nuclear? • carbon sequestration
Jared Diamond on Cultures that Collapse • Easter Island and Maya—deforestation leading to soil erosion