1. Chapter 10 Climate Change Geosystems 6e An Introduction to Physical Geography Robert W. Christopherson Charles E. Thomsen

2. Causes of Climate Change Variations in the Earth’s orbital characteristics Atmospheric carbon dioxide variations Volcanic eruptions Variations in solar output Humans

3. Greenhouse Gases Human activities are enhancing the Earth’s natural greenhouse effect Carbon dioxide, methane, nitrous oxide, CFCs, and water vapor Greenhouse gases are transparent to sunlight but opaque to longwave radiation

5. Carbon Dioxide Atmospheric CO 2 levels began rising during the Industrial Revolution Tremendous fossil fuel burning and heavy deforestation increased CO 2 levels – this trend continues CO 2 is responsible for 64% of global warming

6. Carbon Dioxide Sources

7. What are the Fossil Fuels?

8. Carbon Dioxide Sources

9. Methane Methane currently increasing faster than CO 2 in the atmosphere 19% of total atmospheric warming attributed to methane Methane generated by rotting vegetation, digestion in cattle and termites, burning of vegetation, and melting permafrost

10. Methane (CH 4 )

11. Volcanic Eruptions Sulfur dioxide reacts with water vapor causing haze Combined with ejected particulate matter One of the coldest years in the last two centuries was 1816, the “Year Without a Summer” Caused by eruption of Tambora in 1815 Temperatures can decrease after eruptions for up to 3 years Mount St. Helens

12. Variations in Solar Output Climate models predict that a change in solar output of only 1 percent per century alters the Earth’s average temperature by 0.5 -1.0° C Sunspots Huge magnetic storms Seen as dark (cooler) areas on the sun's surface. Cycle every 11, 90, and 180 years

13. GCM Predictions Crop patterns and natural plant/animal habitats will shift to maintain preferred temperatures During this century, climate regions could shift 90-350 miles poleward Soil moisture projected to decrease in midlatitudes

14. GCM Predictions Forest cover will undergo major species disturbances Expansion of zones affected by tropical diseases Alpine glaciers

15. Global Temperatures Figure 10.28 Low point: 1884 = -0.7 High point: 1998 = +0.7 1.4°C = 2.5°F

16. Temperature Anomalies for 2003 Figure 10.28

17. Sea Level Issues During this century, global warming will cause sea levels to rise at least 1.5 meters (about 4.5 feet).

18. Sea Level Rise During the 20 th century, sea level rose 4-8 inches Could rise 3.5-34.7 inches this century Thermal expansion of water will increase sea level rise Higher sea levels = destruction of small island nations, river deltas, lowland coastal farming, barrier islands

19. July 2029 Temperature Forecast Figure 10.31

20. Disintegration of Ice Shelves In 2002, Larsen-B ice shelve collapsed in 35 days after existing for 11,000 years Warmer ocean and air temperatures are melting shelves on both sides Clear evidence of changes in Earth’s energy balance

21. Antarctic Ice Disintegration Figure 10.32

22. Arctic Climates Changes in ocean temperatures could alter global temperatures Arctic region warmed 9°F since 1987 This has led to a freshening of northern oceans Greenland ice melting at 1m/year Permafrost is melting Increased precipitation in Arctic/Antarctic areas

23. End of Chapter 10 Climate Change Geosystems 6e An Introduction to Physical Geography Robert W. Christopherson Charlie Thomsen

24. Chapter 19 “Ecosystem Essentials” Geosystems 6e An Introduction to Physical Geography Robert W. Christopherson Charles E. Thomsen

25. Ecology Study of relationships between organisms and their abiotic environment Can be studies at several levels: Population Community Ecosystem Biosphere Fig 1.8

26. Communities Fig. 19.3

27. Community Terms Habitat Type of environment where an organism resides Niche Function of a life form within a community In stable community, no niche is left unfilled Competitive Exclusion Principle applies: No two species occupy same niche at same time

28. Interactions in communities Competition Negative for both species (–/–) Symbiotic/Mutualistic (+/+) Both species benefit lichen (fungi and algae) Predation and Parasitic (+/–) One benefits, one loses