1. Copyright © 2011 by Oxford University Press, Inc. Energy and the Environment James A. Fay / Dan S. Golomb FIGURE 11.5 Projected trend of the earth’s surface temperature increase. Upper curve: pessimistic scenario, based on “business-as- usual” fossil fuel consumption. Lower curve: optimistic scenario, based on slowing down of fossil fuel consumption. Middle curve: in between the worst and best scenarios. (Data from Houghton, J. T., G. J. Jenkins, and J. J. Ephraums, eds. Climate Change, the IPCC Scientific Assessment. Cambridge, UK: Cambridge University Press, 1995.)

2. Copyright © 2011 by Oxford University Press, Inc. Energy and the Environment James A. Fay / Dan S. Golomb FIGURE 11.6 Observed average global surface temperature deviation,1850–2000.The scale on the y –axis ( ° C) is indexed to the 1970 global average surface temperature. (Data points from Carbon Dioxide Information Analysis Center, Oak Ridge National Laboratory, 2000; best-fit curve by authors.)

3. Copyright © 2011 by Oxford University Press, Inc. Energy and the Environment James A. Fay / Dan S. Golomb FIGURE 11.7 Rates of carbon exchange between biosphere and atmosphere and between ocean and atmosphere. Also shown are emissions from fossil fuel combustion and forest burning (Gt y –1 ). Also listed are carbon reservoirs in soil, ocean, fossil fuel, and atmosphere (Gt).

4. Copyright © 2011 by Oxford University Press, Inc. Energy and the Environment James A. Fay / Dan S. Golomb FIGURE 11.8 Trend of CO 2 concentrations in the atmosphere 1000–2000 AD (Data from Carbon Dioxide Information Analysis Center. Trends Online: A Compendium of Data on Global Change. Oak Ridge, CA: Oak Ridge National Laboratory, 2000.)

5. Copyright © 2011 by Oxford University Press, Inc. Energy and the Environment James A. Fay / Dan S. Golomb FIGURE 11.9 CO 2 concentration trend, 1958–2010. (Carbon Dioxide Information Analysis Center. Oak Ridge, CA: Oak Ridge National Laboratory, 2010.)

6. Copyright © 2011 by Oxford University Press, Inc. Energy and the Environment James A. Fay / Dan S. Golomb FIGURE 11.10 Globally averaged CH 4 concentration trend, 1980–2009. (Carbon Dioxide Information Analysis Center. Oak Ridge, CA: Oak Ridge National Laboratory, 2010.)