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Environmental Concerns

Environmental Concerns. 1. The thinning of the ozone layer; 2. Climate change. The thinning of the ozone layer.

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Environmental Concerns

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  1. Environmental Concerns 1. The thinning of the ozone layer; 2. Climate change.

  2. The thinning of the ozone layer • chlorofluorocarbons (CFC) used in refrigerators, aerosol sprays , and foam packaging that destroy ozone molecules threaten the ozone layer shielding the surface of our planet from the full force of the sun’s ultraviolet radiation. • The1985 Montreal Protocol.

  3. Climate Change • n signals • n causes • n consequences • n political action

  4. Undisputed Signals • clear signs of warming over the past century; • the 1990s were the hottest decade; • each of the the two poles show signs of rapid warming; • both the temperature trend on the ground and that further up in the atmosphere are rising; • the world’s oceans have warmed up at different depths over the past 65 years; • the link between increased sea-surface temperatures and the frequency of the most intense categories of hurricane, typhoon and tropical storm; • Unsteady ocean currents in the North Atlantic

  5. Some uncertainties over what causes climate change: • a warming trend may be caused not by man but by nature, in the form of small increases in the sun’s heat output; • aerosols such as the tiny little sulphate particles that form when sulphurous fuel is burned, promote the formation of clouds. These reflect sunlight away from Earth and thus oppose the effect of greenhouse gases; • a lack of enough good-quality, long-term, internally consistent data.

  6. Consequences: • between 1990 and 2100 average global temperatures will rise by at least 1.4 C (2.5F) and perhaps by as much as 5.8C (10.4; • sea levels could rise as much as three feet by 2100; • an increase in summer deaths; • droughts an floods will increase; • hurricanes and tropical storms will move farther from the equator, hitting large urban areas that have not been built to cope with them.;

  7. Intergovernmental Panel on Climate Change (IPCC): • an international scientific body • sponsored by the UN, • a peer-reviewed, international collaboration among thousand of scientists.

  8. International treaties on climate change: • 1992: The Framework Convention on Climate Change opened for signature at the Earth Summit in Rio de Janeiro (no specific targets); • 1997: The Kyoto Protocol(specific targets for 39 developed countries; emission trading);

  9. Even if the IPCC suggested reductions were achieved CC may be unavoidable • lag effects of the climate system; • positive feedback.

  10. Actions to limit effects of climate change: • reducing greenhouse-gas emissions by cutting the emissions of carbon dioxide and by mixing in more ethanol and other biofuels; • energy production: away from fuels like oil and coal, and toward cleaner alternatives such as windmills and biomass plants; • building energy efficient buildings; • building sound levees and seawalls, strengthening emergency-preparedness networks and • health-care systems, and much more

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