Climate & Global Change

Transcription

1 Climate & Global Change 29-1 The Earthʼs Carbon Cycle Carbon Budget Carbon Change Rain Forest Biodiversity Human Activities Burning Cycles Natural Changes Desertification Sahel Deforestation Science Concepts Feedbacks Photosynthesis The Earth System (Kump, Kastin & Crane) Chap. 8 (pp )

2 The Carbon Cycle 29-2 Carbon Budget Deforestation Atmosphere /year Land Biota Soil and Detritus 1500 Rivers 0.8 Surface Ocean /year 36 Biota Fossil Fuel Intermediate and Deep Waters /year 0.2 Sedimentation

3 The Carbon Cycle 29-3 Ocean Carbon Budget

4 The Carbon Cycle 29-4 Carbon Change The largest human contribution to climate change Human activity adds CO 2 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 climate/images/carboncycle_jpg_image.html

5 The Carbon Cycle 29-5 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: Rainforest areas are regions of high carbon consumptions Study/LBA/escape.html

6 The Carbon Cycle 29-6 Rainforests Where are they? Area of Closed Country Forest 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 29-7 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 Drug Category 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 29-8 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 The Carbon Cycle 29-9 South American Burning Cycles (Con t)

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

11 Desertification June Desertification/desertification.html? Sahel Sahel stretches across Africa, roughly 15 north of Equator Millimeters per year Satellite measurements of vegetation reveal it as a transition zone between sands of the Sahara and jungles of the Congo in heart of Africa N 60 N 30 N 0 30 S 60 S 90 S Latitude Rainfall Runoff Evaporation

12 Desertification Sahel (Con t) Collapse N Soil Condition: Grams of vegetation per 10,000 m 2 (N = 450) Cattle, Camels, & Goats (N = 600,000) N/2 Population (N = 150,000) Year Study/Desertification/ desertification2.html

13 Desertification Sahel (Con t) MODIS - Albedo Albedo Study/Desertification/ desertification2.html

14 Desertification Sahel (Con t) Change 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) 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 Eos, Vol. 88, No. 3, 16 January 2007

17 Deforestation Brazilian Rainforests

18 Deforestation Rondonia, Brazil

19 Deforestation Guatemala

20 29-20 Deforestation Guatemala 1986 to Peten, Guatemala Peten, Guatemala Red is forest; Greens are roads and cleared land Area of picture about 40% size of New Jersey

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 ) Chap. 14 (pp

24 System Dynamics Positive Feedback Desertification - Sahel Ice - Albedo feedback Negative Feedback CO 2 - Cloud - Albedo feedback CO 2 - Plankton feedback