Climate & Global Change

1. Climate & Global Change Science Concepts Feedbacks Photosynthesis The Earth’s Carbon Cycle Carbon Budget Carbon Change Rain Forest Biodiversity Human Activities Burning Cycles Natural Changes Desertification Sahel Deforestation The Earth System (Kump, Kastin & Crane) • Chap. 8 (pp. 165-167)

2. The Carbon Cycle Carbon Budget Deforestation Atmosphere 750 + 3/year 2 5 102 50 50 92 90 Land Biota 550 50 Surface Ocean 1000 + 1/year Rivers 0.8 Soil and Detritus 1500 36 Biota 3 40 4 5 37 Intermediate and Deep Waters 38000 + 2/year Fossil Fuel 0.2 Sedimentation

3. The Carbon Cycle Ocean Carbon Budget

4. The Carbon Cycle Carbon Change • The largest human contribution to climate change • Human activity adds CO2 to the atmosphere - Fossil fuels - biomass burning - cement production • Carbon dioxide naturally cycles among the land, atmosphere and oceans • Knowledge of the carbon cycle is essential to forecasting human influences on climate http://www.windows.ucar.edu/tour/link=/earth/ climate/images/carboncycle_jpg_image.html

5. The Carbon Cycle Net Primary Productivity • Amount of carbon consumed by plants (both on land and in the ocean) per square kilometer, called net primary productivity, in 2002 • Note: Rain- forest areas are regions of high carbon consumptions http://earthobservatory.nasa.gov/ Study/LBA/escape.html

6. The Carbon Cycle Rainforests • Where are they? Area of Closed CountryForest in 1985 (Hectares) Brazil 357,480,000 Indonesia 113,895,000 Zaire 105,750,000 Peru 69,680,000 India 51,841,000 Colombia 46,400,000 Mexico 46,250,000 Bolivia 44,010,000 Papua New Guinea 34,230,000 Burma 31,941,000 Venezuela 31,870,000 Congo 21,340,000 Malaysia 20,995,000 Gabon 20,500,000 Guyana 18,475,000 Cameroon 17,920,000 Suriname 14,830,000 Ecuador 14,250,000 Madagascar 10,300,000

7. The Carbon Cycle Rainforests (Con’t) • Biodiversity Importance - Bushmaster snake (lives in the rainforest) venom used as a pattern to make hypertension medicine. - As of 1985, 119 pure chemical substances extracted from higher plants were used in medicine. Therapeutic Plant DrugCategory Foxglove Digitoxin Cardiotonix Opium poppy Codeine Analgesic Morphine Sedative Tobacco Nicotine Insecticide May apple Podophyllotoxin Cancer White willow Salicin Analgesic (Asperin - known to Hippocrates) Cocoa, Cacoa Theobromine Diuretic Curare Tubocurarine Skeletal muscle relaxant (Arrow poison) Pacific yew Toxal Ovarian Cancer (4-6 trees to treat 1 woman) (~200,000 trees exist) (20,000 cases per year)

8. The Carbon Cycle South American Burning Cycles • 1998 fires Jan - Dec • Note - Aug/Sept/ Oct max for central and southern regions • Note - Feb/Mar max for northern area

9. South AmericanBurning Cycles (Con’t) The Carbon Cycle

10. The Carbon Cycle African Burning Cycles• 1998 fires Jan - Dec • Dec/Jan max through central Africa, Jun/Jul max farther south

11. Rainfall 2000 Evaporation 1500 1000 Millimeters per year Runoff 500 0 -500 90°N 60°N 30°N 0° 30°S 60°S 90°S Latitude Desertification June 2005 http://earthobservatory.nasa.gov/Study/ Desertification/desertification.html? Sahel • Sahel stretches across Africa, roughly 15° north of Equator • Satellite measurements of vegetation reveal it as a transition zone between sands of the Sahara and jungles of the Congo in heart of Africa

12. Desertification Sahel (Con’t) • Collapse Soil Condition: Grams of vegetation per 10,000 m2 (N = 450) N Cattle, Camels, & Goats (N = 600,000) N/2 Population (N = 150,000) 1920 1960 2000 2040 Year http://earthobservatory.nasa.gov/ Study/Desertification/ desertification2.html

13. Albedo 0.50 0.45 0.40 0.35 0.30 0.25 0.20 0.15 0.10 0.05 0.00 Desertification Sahel (Con’t) • MODIS - Albedo http://earthobservatory.nasa.gov/ Study/Desertification/ desertification2.html

14. Desertification Sahel (Con’t) • Change http://earthobservatory.nasa.gov/ Study/Desertification/ desertification2.html

15. Desertification Sahel (Con’t) • 2003 data spatially averaged over area 8.5ºW–8.5ºE and 12.5º–15.5ºN • Monthly mean precipitation in millimeters per day (blue) • Fraction of Absorbed Photosynthetically Active Radiation (FAPAR) (green) • Broadband surface albedo (red) http://www.agu.org/journals/eo/eo0703/2007EO030002.pdf#anchor Eos, Vol. 88, No. 3, 16 January 2007

16. Desertification Sahel (Con’t) • 1984 and 2003 latitudinal profile of total June to October (JJASO) precipitation • 1984 and 2003 mean August to October (ASO) broadband surface albedo averaged between 18ºW and 20ºE http://www.agu.org/journals/eo/eo0703/2007EO030002.pdf#anchor Eos, Vol. 88, No. 3, 16 January 2007

17. Deforestation Brazilian Rainforests 1975 1986

18. Deforestation Rondonia, Brazil 1973 1978 1983

19. Deforestation Guatemala

20. Deforestation Guatemala• 1986 to 1997• Red is forest; Greens are roads and cleared land• Area of picture about 40% size of New Jersey 1997 - Peten, Guatemala 1986 - Peten, Guatemala

21. Deforestation Facts• Equivalent of ten city blocks of rainforest is destroyed every minute, that an area the size of Pennsylvania lost every year • 7% of the Earth's dry land surface is rainforest, home to more than 50% of the world's plants and animals • A bulldozer must remove 60 rainforest trees to reach one mahogany tree • There are 100 different species of large trees in a single acre of rainforest

22. Deforestation Facts• Estimate rate of deforestation

23. System Dynamics The Earth System (Kump, Kastin & Crane) • Chap. 2 (pp. 18-20) • Chap. 14 (pp. 279-280

24. System Dynamics Positive Feedback • Desertification - Sahel • Ice - Albedo feedback Negative Feedback • CO2 - Cloud - Albedo feedback • CO2 - Plankton feedback