1. Climate Change Climate is what we expect, weather is what we get. ~Mark Twain

4. Climate Average weather conditions of the Earth or a particular area Main focus: temperature & precipitation Minimum period: 3 decades

5. Climate Change: Historical Radioisotopes in rocks & fossilsrocks Plankton & radioisotopes in ocean sediments Pollen from the bottom of lakes & ponds Tree rings Ice cores Regular temperature measurements (1861)

6. Climate Change

7. Climate Change: Historical Volcanic Emissions Changes in solar input Impacts by meteors Changes in air & ocean circulation

8. Climate Change: Human Activities Significant increase in greenhouse gases (CO 2, CH 4, & N 2 O) since mid-1700s –Industrial revolution –Burning fossil fuels –Deforestation –Agriculture

11. Carbon dioxide (CO2) Year 1800190020002100 260 310 360 410 Parts per million Fig. 18.4a, p. 450

12. Methane (CH 4 ) Year 1800190020002100 0.6 1.2 1.8 2.4 Parts per million Fig. 18.4b, p. 450

13. Year Parts per million 1800190020002100 260 290 300 310 320 Fig. 18.4c, p. 450 Nitrous Oxide

14. Year 199020002025205020752100 100 150 200 250 Index (1900 = 100) Carbon dioxide Methane Nitrous oxide Fig. 18.5, p. 451

16. Intergovernmental Panel on Climate Change (IPCC) Earth’s lower atmosphere is warming Most increase in gases are due to human activities Combo of human induced changes to air composition & temperature of the atmosphere are beginning to change the Earth’s climate Increased greenhouse gas conc. will likely trigger a significant climate disruption this century Climate disruption will have ecological, economic, & social effects

17. IPCC (2010) 1906–2005: Ave. temp increased about 0.74˚C 1970–2009: Annual greenhouse emissions from human activities up 70% 2000-2009 warmest decade since 1881 Past 50 years: Arctic temp rising almost twice as fast as the rest of the earth Melting of glaciers and increased floating sea iceMelting of glaciers Last 100 years: sea levels rose 19 cm

19. Key Players in Climate Change Carbon Dioxide Waste Heat Solar Input Oceans Cloud Cover

20. CO2 Emissions Role Mainly burning of fossil fuels –Burning forest (agriculture) –Deforestation 1850: 285 ppm 2010: 389 ppm 2050: 560 ppm Tipping point: 450 ppm

22. Carbon Emitters (2009) Total 1.China 2.United States 3.European Union(27) 4.Indonesia 5.Russia Per Capita 1.Australia 2.United States 3.Canada 4.Netherlands 5.Saudi Arabia

23. Heat Waste Burning fossil fuels Main sources –Combustion engines –Power plant –Lights

24. Solar Input No correlation between increased solar input & increase temperatures Since 1975 –Troposphere warmer –Stratosphere cooler

25. Oceans Carbon Sink –Absorbs 25=30% of anthropogenic CO 2 –Cooler temps = increased absorption Warmer Oceans –Average temp = increase 0.32-0.67 ⁰ C –Less CO 2 absorptions Ocean Acidity –Increased 30% in last 200 years –Affects: coral bleaching, phytoplankton populations, & ability to absorb CO 2

26. Cloud Cover Increase temp = increased evaporation = increase in clouds Low clouds: decrease surface temp High clouds: increase surface temp

27. Climate Change Possible Effects…

29. Droughts Severe/prolonged droughts affect 30% of Earth Consequences: –Increased wildfires –Decrease in water –Decrease in agriculture

30. More Ice & Snow Melt

31. Arctic Temperatures have risen at twice the rate Mountain glaciers affected by: –Average snowfall –Average temperatures Mountain glaciers supply water to rivers

32. Permafrost Melt Releases methane

33. Permafrost Melt

34. Sea Level Rising Prediction: 0.8-2 meter rise by 2100

35. Sea Level Rise Effects Degradation of coastal estuaries & wetlands Disruption of coastal fisheries Coastal flooding –Shanghai –New York –Miami –Bangkok –Calcutta Area floods with one meter rise

36. Sea Level Rise Effects Flooding of low-lying barrier islands Area floods with one meter rise

37. Sea Level Rise Effects Flooding of agriculture lowlands & deltas Saltwater contamination of freshwater

38. Extreme Weather Increase Heat waves Hurricanes –increase 0.8°C = increase in storms by 1/3 –Intensity increase by 45% Flooding/droughts increase

39. Threat to Biodiversity Most susceptible areas: –Coral reefs –Polar seas –Coastal areas –Tundra Organisms with limited ranges & temperature tolerance

40. Agriculture Regions of farming may shift –Decrease at tropics & subtropics –Increase in northern latitudes Low productivity because of low soil quality

41. Human Health Temperature related death increase Increase in insects, molds, & microbes

42. Climate Change What can we do…

43. Difficult to do... Global issue Long term political issue Impacts are not distributed evenly Proposed solutions disrupt economies & lifestyles

44. Ways to Manage Greenhouse Gases Improve energy efficiency Increase use of renewable resources Stop deforestation Shift to more sustainable agriculture

45. Collect Greenhouse Gases Massive tree planting Restore wetlands Plant perennials on degraded land Preserve and restore natural forests Stimulate phytoplankton growth

46. Government Involvement Strictly regulate CO 2 and CH 4 Carbon tax on fossil fuelsCarbon tax Cap and trade approach Increase subsidies to encourage energy efficiencyefficiency

48. Kyoto Protocol 1997 treaty to slow climate change Reduce CO 2, CH 4, & N 2 O emissions by 5.2% by 2012 Not signed by US