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Energy & Its Impact on Global Society Jerome K. Williams, Ph.D. Saint Leo University Dept. Mathematics & Sciences
Chapter 9: Global Warming & Thermal Pollution • Overview • Greenhouse Effect & Global Warming • Possible Impacts: Global Warming • Actions: What can be Done? • Thermal Pollution
Overview • http://www.youtube.com/watch?v=rn1n-YYHs4g
Overview • Evidence suggests that burning fossil fuels can raise Earth’s temperature and potentially change the climate of the entire planet. • Global Warming (Greenhouse Effect)
Greenhouse Effect & Global Warming • Greenhouse effect caused by gases in atmosphere that absorb infrared energy from the Earth that would otherwise escape into space. • Earth’s temperature is a balance between the energy coming in from Sun and energy that is radiated from Earth back into space.
Greenhouse Effect & Global Warming • Gases that are responsible for this effect: • Carbon dioxide (CO2) • Methane (CH4) • Nitrogen oxides (NO NO2) • Chlorofluorocarbons (CFCs)
Greenhouse Effect & Global Warming • GWP = Global Warming Potential (ability of greenhouse gas to trap heat). • CO2 levels are a Global Problem that can have devastating environmental consequences if not addressed soon.
Global Warming Consequences • http://www.youtube.com/watch?v=98RdhAaLd2k
Global Warming Consequences • http://www.youtube.com/watch?v=ctRvtxnNqU8
Possible Impacts: Global Warming • Determining the impact of global warming in the 21st century is very difficult • Climate models about complex physical processes are based on assumptions and therefore contain many uncertainties
Possible Impacts: Global Warming • Climate Sensitivity - defined as temperature rise that will occur when CO2 concentrations double from pre-industrial levels • Many scientists think that doubling will occur by middle of this century (assumes a 1-2% annual increase in CO2 levels is maintained)
Possible Impacts: Global Warming • Most scientists (but not all) agree that increasing CO2 levels will affect the planet’s climate, the key questions are as follows: • How much of a change will be observed? • How fast will global temperatures rise?
Possible Impacts: Global Warming • A key element in predicting the rise in global temperatures is to understand carbon cycle
Possible Impacts: Global Warming • Much of uncertainty with predicting warming trends depends on understanding of sizes of various feedbacks that may occur in response to climate changes
Possible Impacts: Global Warming • Effects of global warming will not be felt equally around the world. • Poorer nations more susceptible to effects of global warming; widespread poverty across Africa makes it particularly vulnerable
Actions: What can be Done? • What can be done to prevent greenhouse gas concentrations from rising to unacceptable levels? • Energy Policy coupled with Political Leadership
Actions: What can be Done? • Energy Policy: • Energy conservation • Economic incentives • Renewable energy technologies • Employ more natural gas & nuclear power • US: 20 metric tons CO2 /yr (6X greater than developing world)
Actions: What can be Done? • Political Leadership (Legislative Action) • “Cap and Trade” Policy • Carbon Tax • Carbon Sequestration
Actions: What can be Done? • Will Everyone Play in the same Sand Box? • International strategies must be developed and followed by everyone for this to work • Built-in-bias against solving long-term problems • Very expensive to fix problem; affects bottom line • Controversial (skeptics still out there)
Actions: What can be Done? • Recent History: Do Nations Play well together? • 1992 Earth Summit (Rio de Janeiro) • Countries must exercise “responsible stewardship” • Compliance was voluntary • 1997 Kyoto Protocol on Global Climate Change
Thermal Pollution • Thermal pollution is defined as addition of unwanted heat to environment, particularly natural waters • Greatest source of heated water is from power-generating stations
Thermal Pollution • Ecological Effects of Thermal Pollution • Decreased ability of water to hold oxygen • Increased rates of chemical reactions • Changes in food chain of ecosystem • Long-term damage (even death) to natural bodies of water
Thermal Pollution • Current US laws dictate that one can not just “dump” waste heat directly into aquatic environments • Cooling Towers • Cooling Ponds
Thermal Pollution • Using Waste Heat for other Benefits include • Hot water for industrial use • Aquaculture (increased fish growth) • Greenhouse heating • Desalination of sea water • Increased crop growth and frost protection
Problems • 1, 2, 3