Sheila Watt-Cloutier, Inuit Circumpolar Conference (2004)

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1 "People worry about the polar bear becoming extinct by 2070 because there will be no ice from which they can hunt seals, but the Inuit face extinction for the same reason and at the same time. Sheila Watt-Cloutier, Inuit Circumpolar Conference (2004)

2 Civilization as we know it will come to an end sometime in this century unless we can find a way to live without fossil fuels. David L. Goodstein, Professor of Physics and Applied Physics at Caltech (2004)

3 Three levels of biodiversity Figure 55.1

4 4 5 major threats to biodiversity 1. Habitat destruction

5 Deforestation in the United States

6 The history of habitat reduction and fragmentation in a Wisconsin forest

7 Species diversity of American birds.

8 Figure Some biodiversity hot spots

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10 2. Introduced Species Disastrous species introductions: Nile perch (top left), brown tree snake (top right), Argentine ants (bottom left), seaweed Caulerpa (bottom right)

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13 3. Over Exploitation The great auk (Pinguinis impennis)

14 North Atlantic bluefin tuna auctioned in a Japanese fish market

15 Time trends of community biomass in oceanic (a-i) and shelf (j-m) ecosystems. Relative biomass estimates from the beginning of industrial fishing. Number of fish caught per 100 hooks on pelagic longlines by the Japanese fishing fleet. (Myers and Worm (2003) Science 423: )

16 Spacial patterns of relative predator biomass through time. Color codes depict the number of fish caught per 100 hooks on pelagic longlines set by the Japanese fleet. (Myers and Worm (2003) Science 423: )

17 Blue marlin Sailfish Swordfish Compensation in exploited fish communities. Oceanic billfish community in the tropical Atlantic, showing the catch per 100 hooks of blue marlin (solid circles, solid line); sailfish (open triangles, dashed line); and swordfish (open circles, dotted line). cod flatfish Demersal (bottom dwelling) fish community on Southern Grand Banks, showing the biomass of codfishes (solid circles, solid line) and flatfishes (opencircles, dotted line). Myers and Worm (2003) Science 423:

18 4. Climate Change Rising global temperatures is melting polar ice.

19 The greenhouse effect is being increased by release of certain gases to the atmosphere that cause the Earth's temperature to rise. This is called "global warming." Carbon dioxide (CO2) accounts for about 85 percent of greenhouse gases released in the United States. Carbon dioxide emissions are largely due to the combustion of fossil fuels in electric power generation. Methane (CH4) emissions, which result from agricultural activities, landfills, and other sources, are the second largest contributor to greenhouse gases in the United States.

20 Northern Hemisphere temperature history Science (2002) 297:

21 Time series of departure from the 1961 to 1990 base period for annual mean global temperature (bars) and for a carbon dioxide mean of 334 ppmv(solid curve) during the base period. (Karl and Trenberth Science 302: )

22 Governing Council of the American Geophysical Union (2003) Scientific evidence strongly indicates that natural influences cannot explain the rapid increase in global near-surface temperatures observed during the second half of the 20th century. Atmospheric carbon dioxide concentrations have increased since the mid-1700s through fossil fuel burning and changes in land use, with more than 80% of this increase occurring since Moreover, research indicates that increased levels of carbon dioxide will remain in the atmosphere for hundreds to thousands of years. It is virtually certain that increasing atmospheric concentrations of carbon dioxide and other greenhouse gases will cause global surface climate to be warmer. Mid-continent warming will be greater than over the oceans, and there will be greater warming at higher latitudes. Some polar and glacial ice will melt, and the oceans will warm; both effects will contribute to higher sea levels. The hydrologic cycle will change and intensify, leading to changes in water supply as well as flood and drought patterns. There will be considerable regional variations in the resulting impacts.

23 Alternatively, the global thermohaline conveyor belt circulation may shut down. Alternatively, the global thermohaline conveyor belt circulation may shut down.

24 Evidence that a thermohaline circulation collapse may be imminent, as the North Atlantic is increasingly being freshened by surrounding seas that have become less salty over the past 40 years. (Schwarz and Randall, 2004)

25 Consequences of an abrupt climate change due to slowing of ocean s thermohaline conveyor. Schwartz and Randall (2003) Report for Pentagon - Annual average temperatures drop by up to 5-6 o F in Northern Hemisphere. - Annual average temperatures increase by up to 4 o F in Southern Hemisphere. - Drought in Europe and North America. - Winter storms and winds intensify. - Food shortages due to decreases in net global agricultural production. - Decreased availability and quality of fresh water. - Disruption of access to energy supplies due to extensive sea ice and storminess. - Global and local carrying capacities are reduced. - International tensions rise. - Nations with the resources build defenses to protect resources. - Less fortunate nations initiate struggles for access to food, water, and energy.

26 End of Oil Reserves Threat #5 Ratio of known reserves of oil to rate of use is 40.6 years (British Pertrolium Web Site).

27 In 1956 Marion Hubbert, a geophysicist employed by Shell Oil Company, predicted that the rate at which oil could be extracted from the lower 48 states would peak around 1970 and decline rapidly after that. He was right to the year. U.S. oil extraction peaked at 9 million barrels per day in 1970 and has been declining ever since. Using the same approach oil geologists now predict that the worldwide peak in extraction will occur sometime within this decade. Of the 2 trillion barrels of oil we started with, nearly half has already been consumed. Given that demand will continue to increase, the crisis is predicted to occur when the peak in production is reached rather than when the last drop is pumped. We will be in trouble when we have used up half the oil that exists. David Goodstein, Out of Gas (2004)

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38 I don t know how I am to make a fire on that island, there is no wood! Cook on research expedition to Easter Island in 1914

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49 Ecological footprint in relation to available ecological capacity We are at our carrying capacity. 1997

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