Average earth temp- 13.9

Spring days 6 earlier than 1959/Autum 12 days later

increased frequency of hot humid days during summer.

Rising sea level

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Climate Change

*Human air pollutants caused most climate warming in last 50

  years.

*projects .2 D/C. in global temp in next 2 decades

*projects1.8-4D/C in global temp by 2100

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Causes of Global Climate Change

*CO2 increase in atmosphere from 288ppm to 382ppm last

  200yrs.

*Lvls of Trace gases are rising

              -Methane, Nitrous Oxide, CFC, O3

*Green house gas: Water Vapor

              - amplifies warming, warmer air = grater evap.

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Global Climate Change

*Occurs because gases absorb infrared radiation 

  in atmosphere

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Greenhouse Efffect

*Trapping of heat in atmosphere

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Greenhouse Gases

* Gases that absorb radiation

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Enhanced Greenhouse effect

*Additional warming due to increased lvls of gases