Today: Global Climate Change

Fig 54.14 Carbon cycle

Solar energy: incoming and outgoing http://www.esr.org/outreach/climate_change/basics/basics.html

http://www.esr.org/outreach/climate_change/basics/basics.html

Sunlight shifts wavelength from short to long http://www.esr.org/outreach/climate_change/basics/basics.html

CO2 and other greenhouse gases keep heat from radiating back into space http://www.esr.org/outreach/climate_change/basics/basics.html

CO2 levels in Hawaii and average global temp. Fig 54.15

http://www.esr.org/outreach/climate_change/basics/basics.html

Gases trapped in ice core bubbles can tell us about past climate conditions.

http://www.esr.org/outreach/climate_change/basics/basics.html

http://www.esr.org/outreach/climate_change/basics/basics.html

Recent increases in global temperature have reversed a slight cooling trend

Vikings in Greenland in the 1200- 1400’s

As the climate cooled, the Vikings were forced to abandon their outposts

370

Relative contributions to Global Warming ~500 m people ~300 m people ~2.5 b people

Effects of global warming are already visible http://www.worldviewofglobalwarming.org/pages/glaciers.html

Observed and projected ice cap melting http://www.esr.org/outreach/climate_change/basics/basics.html

http://www.esr.org/outreach/climate_change/basics/basics.html

Global Change & Human Health (2001) V 2 # 1 pg 64

Precipitation changes 1900 to 2000

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