1. Rapid warming is changing the global climate The scientific debate about global warming is over—cause of warming is still debated –Global temperature has risen –0.8°C in the last 100 years –0.6°C of that increase occurred in the last three decades –2 to 4.5°C increases are likely by the end of the 21st century Global warming most evident in arctic –Shrinking sea ice –Thinning ice sheets –Melting permafrost

2. –2 –1.6 –1.2 –.8–.4 –.2.2.4.81.6 1.2 2.1

3. 2005 1981 1938 Grinnell Glacier: Glacier National Park Montana

4. Human activities are responsible for rising concentrations of greenhouse gases Atmospheric CO 2 did not exceed 300 ppm for 650,000 years Atmospheric CO 2 is approximately 385 ppm today High levels of methane and nitrous oxide also trap heat

5. 1500 10002000 Year 1000 2000 1800 1600 1400 1200 800 600 500 0 250 400 350 300 Carbon Dioxide (CO 2 ) Methane (CH 4 ) Nitrous Oxide (N 2 O) CO 2 (ppm), N 2 O (ppb) CH 4 (ppb)

7. The Greenhouse Effect: Causes CO2 into the atmosphere from fossil fuels (coal) CO2 into the atmosphere from burning gasoline Methane emissions from livestock (cows! And melting ice) Deforestation Chemical Fertilizers

8. Greenhouse Effect vs. Ozone Loss Ozone protects Earth from harmful UV light Lower stratosphere Hole caused by CFCs Unrelated to Greenhouse gases and warming

9. Global climate change affects biomes, ecosystems, communities, and populations Terrestrial biomes determined by temperature and rainfall –Changing as a consequence of global warming –Distributions of populations and species also changing –Disappearance of many species being caused by changing climate –Climate change affects seasonal events in some plants and animals