Chapter 5: Natural Systems Under Stress

1. Chapter 5: Natural Systems Under Stress Daniel Burton Geoff Koegler

2. Overview • Chapter Summary • Fact Check

3. Natural Systems Under Stress “Mercilessly expanding human demands are putting stresses on forests, rangelands, and fisheries that they cannot withstand. We are also destroying many of the plant and animal species with which we share the planet”.

4. Shrinking Forests • Effects of Deforestation • Pressures on Deforestation • The importance of the world’s forests

5. Losing Soil • Topsoil and soil erosion • Dust Bowl Examples • Global effects of Dust Bowls

6. Grassland to Desert • Grass-based livestock economies • Livestock Vs. Carrying Capacity • Land Degradation

7. Advancing Deserts • Desertification • Stages of Desertification • Effects of Desertification

8. Collapsing Fisheries • Demand increase for seafood • Effects of over-fishing • Canadian Cod • EU Solution • Dead Zones

9. Disappearing Plants and Animals • The sixth great extinction • Habitat Destruction • Bird Population • Bee Population • Non-native Species

10. Fact Check: Natural Systems Under Stress • Loss of Forests • Desertification • Collapsing Fisheries • Extinction

11. Loss of Forests • Brown: Forests make up 4 billion hectares today, down from 5 billion in 1900 • U.N. FAO:

12. Loss of Forests • Forest cover is growing in developed countries (U.N. FAO)

13. Loss of Forests • Forest cover is declining in developing countries (U.N. FAO)

14. Loss of Forests • The Amazon • Brown: Brazil has lost 20% of the Amazon since 1970 • U.N. FAO:

15. Desertification • Brown: Sahara Desert is growing rapidly • Nigeria: losing 351,000 hectares of land each year • Center for International Earth Science Information: • Lack of rain is the largest cause

16. Desertification • Brown: China losing 3,600 square km per year, up from 2,100 in the 1970s and 80s, • Resulted in the loss of over 24,000 villages during the past 50 years • China is indeed losing this much land (China Environmental Science Presses) • Disputes as to how many villages have been lost (4,000 according to the Boston Globe)

17. Collapse of Fisheries • Brown: World-wide fish catch at a historic high of 96 million tons in 2000, 75% of fisheries are over fished • U.N. FAO: • 80% of Fisheries are over fished (Oceana)

18. Collapse of Fisheries • Brown: Canadian Cod Fishery collapsed in 1990 as a result of overfishing • U.N. FAO:

19. Collapse of Fisheries • Brown: Chesapeake Bay oyster catches have decreased rapidly • Chesapeake Bay Program:

20. Collapse of Fisheries • Brown: Gulf of Mexico “Dead Zone” (size of New Jersey) kill fish due to algae blooms • Sierra Club: 4,565 square miles, roughly the size of Connecticut (NASA)

21. Extinction • Brown: An alarming amount of species are vulnerable or in immediate danger of extinction • 12% of birds • 20% of mammals • 39% of fish • Conservation International Study • 36% of land mammals • 61% of ocean mammals

22. Summary • Lester Brown clearly depicts how several of earth’s natural systems are under stress • Uses accurate and interesting information to convey issues regarding: • Loss of Forests • Desertification • Collapsing Fisheries • Extinction

23. “On the plus side, we now have more information on the state of the earth and the life on it than ever before. While knowledge is not a substitute for action, it is a prerequisite for saving the earth’s natural systems- and the civilization that they support”.

24. Questions?

25. References • Chesapeake Bay Program. (2008). Oysters: Commercial Harvest. Retrieved October 25, 2008, from http://www.chesapeakebay.net/status_oysterharvest.aspx?menuitem=19819 • Compton, T, Dregne, H, Newcomb, W. (1991). Expansion and Contraction of the Sahara Desert from 1980 to 1990. Center for International Earth Science Information Network Retrieved October 25, 2008, from http://www.ciesin.org/docs/005-319/005-319.html • Datong, Ning. (1989). An Assessment of the Economic Losses Resulting from Various Forms of Environmental Degradation in China. China Environmental Science PressesRetrieved October 25, 2008, from http://www.library.utoronto.ca/pcs/state/chinaeco/desert.htm • Food and Agriculture Organization of the United Nations. (2008). Fisheries and Aquaculture Department. Retrieved October 25, 2008, from http://www.fao.org/fishery/en • Food and Agriculture Organization of the United Nations. (2008). Forestry. Retrieved October 25, 2008, from http://www.fao.org/forestry/home/en/ • NASA. (2007). Mississippi Dead Zone. Retrieved October 25, 2008, from http://www.nasa.gov/vision/earth/environment/dead_zone.html • Oceana. Over 80% of Fisheries Overfished: Report. Retrieved October 25, 2008, from http://www.oceana.org/fileadmin/oceana/uploads/dirty_fishing/cut_the_bait/AFP_27_may_08.doc • Pocha, J. (September 18, 2006). China’s Dangerous Dustbowl. Boston Globe. Retrieved October 25, 2008, from http://www.boston.com/yourlife/health/other/articles/2006/09/18/chinas_dangerous_dustbowl/ • Roach, J. (October 5, 2004). Bee Decline May Spell End of Some Fruits, Vegetables. National Geographic News. Retrieved October 25, 2008, from http://news.nationalgeographic.com/news/2004/10/1005_041005_honeybees.html • Sierra Club. (2008). The Dead Zone in the Gulf of Mexico. Retrieved October 25, 2008, from http://www.sierraclub.org/cleanwater/waterquality/deadzone.asp • Weiss, K. (October 6, 2008). Many Wild Animals Face Extinction, Survey Finds. Chicago Tribune. Retrieved October 25, 2008, from http://www.chicagotribune.com/news/nationworld/chi-extinct-mammalsoct07,0,1044472.story