Population Resources Environment Population boom falling death rates
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 • 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 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 -voa 48. 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? • CO 2 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
water shortage
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
Per capita carbon emissions
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 Maya—deforestation leading to soil erosion
- Slides: 24