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Criteria for Crisis Overuse and Pollution of Fresh Water PROBLEM Extensive contamination of ground water Depletion of aquifers Subsidence of ground in some areas Overuse of fresh water resources Ex: Colorado River Ex: Jordan River. Criteria for Crisis
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Criteria for Crisis • Overuse and Pollution of Fresh Water • PROBLEM • Extensive contamination of ground water • Depletion of aquifers • Subsidence of ground in some areas • Overuse of fresh water resources • Ex: Colorado River • Ex: Jordan River
Criteria for Crisis • Overuse and Pollution of Fresh Water • NO PROBLEM • Still plenty of fresh water in most areas, and new delivery methods work well • New purification techniques offer promise for the future • Desalination • Reclamation (“Toilet to Tap”)
Criteria for Crisis • Deforestation • PROBLEM • Forested area has been shrinking for centuries, and rate of deforestation has increased dramatically in past 50 years • Less than 20% of original forest cover remains in many countries • Philippines, Madagascar, Scotland • Health of forests declining as well • US Forest Service estimated growth rate of yellow pines in SE United States declined 30-50% between 1975 and 1985, while fraction of dead trees increased from 9% to 15%
1945 1960 1974 1990 Bahia http://www.nybg.org/bsci/res/bahia/Defor.html
Criteria for Crisis • Deforestation • NO PROBLEM • Globally, replanting more than makes up for deforestation • Managed properly, the cultivation of trees as an agricultural crop (silviculture) makes good use of a valuable renewable resource.
Criteria for Crisis • Global Climate Change • PROBLEM • Lester Milbrath (SUNY Buffalo) • “Devastation from climate change will be exacerbated by other global biospheric effects: loss of the ozone layer, acid rain, poisonous red tides of algae, toxic pollution of soil, water, and air, and species extinction."
Criteria for Crisis • Global Climate Change • PROBLEM • Effects • Rise in sea level (ca. 3-4 mm y-1) • Shifting of climate zones • Widespread drought in agricultural regions • Declining populations of marine plankton • Additional effects through food web • Increased summer deaths from heat
Criteria for Crisis • Global Climate Change • NO PROBLEM • Rush Limbaugh • “Global warming is a scam invented by environmental scientists to increase their research funding” • Environmentalists are guilty of exaggerating the gravity of the situation • Present hypotheses as certainties and predictions as facts • Misrepresent evidence and compromise credibility • Current climate models aren’t complete • Only account roughly for role of ocean as a reservoir for heat (ATOC) • Climategate!
Criteria for Crisis • Energy Availability • PROBLEM • “If it were not for the world's predominant reliance on fossil fuels for transportation and energy generation, the problems of global warming, acid rain and urban smog would be relatively minor” • Energy costs should be adjusted to reflect the environmental costs associated with their generation • Renewable energy resources need to be encouraged • 2005: Growing energy demand in the US will require the construction of 250 large coal or nuclear power plants (or their equivalent) by the year 2015 • Nuclear fission plants are unsafe and produce hazardous waste that requires long-term secure storage • Hydroelectric facilities produce no GHGs but are environmentally problematic
Criteria for Crisis • Energy Availability • NO PROBLEM • New and alternative technologies offer promise for the future • Natural gas • Requires expansion of infrastructure • Requires new technology (hydrofracking) • Nuclear power (with proper regulation and security) • Solar power • Energy from the sea • Fuel cells
Population Dynamics - History • Thomas Malthus (1766-1834) • English parson • Became concerned that unrestricted population growth would cause demand to exceed availability of resources • Predicted widespread poverty and famine • Global population < 1 billion • Malthusians - People who forecast disaster due to overpopulation • Many of Malthus’ predictions did not occur • Agricultural improvements (did not foresee) • Birth control (rejected on moral grounds)
Population Dynamics - History • Demographic Transition • Theory developed to explain human population dynamics in response to economic development • Cohen – Four Stages • High birth & death rates (nearly equal but variable) Growth rate low • Death rate falls and becomes less variable, birth rate still high Growth rate rises, population increases. Mortality transition • Birth rate drops, death rate remains low or declines, growth rate slows, population increases. Fertility transition • Low birth & death rates (nearly equal, not variable), growth rate low or negative, population larger than before (1) • This process has occurred in many developed nations • United States, Canada, Japan, Western Europe