FIGURE 1-1 Average temperatures on Earth.

FIGURE 1-1 Average temperatures on Earth.

SOURCE: Adapted from World Health Organization, World Meteorological Organization, and United Nations Environment Programme (2003:Figure 1-1).

The consequences of a warmer Earth, although not precisely predictable, are already evident (Intergovernmental Panel on Climate Change, 2007b; Millennium Ecosystem Assessment, 2003; Arctic Climate Impact Assessment, 2005; National Research Council, 2008a) and are expected to increase across a range of areas vital to human well-being and the socioeconomic security of the United States (e.g., Intergovernmental Panel on Climate Change, 2007b; National Research Council, 2008b). The U.S. Climate Change Science Program (CCSP) concluded (with confidence greater than 90 percent) that temperature increases, increasing CO2 levels, and altered patterns of precipitation are already affecting U.S. water resources, agriculture, land resources, and biodiversity (Backlund et al., 2008). There is also some evidence that more intense hurricanes are occurring more frequently globally (Webster et al., 2005; Chang and Guo, 2007; Holland and Webster, 2007; Kossin et al., 2007), and the scientific consensus is that such storms are likely to become more intense in the future (Intergovernmental Panel on Climate Change, 2007a). Climate change is also projected to have major effects on human health, water resources, ecosystems, and agriculture, as well as other systems and sectors (Intergovernmental Panel on Climate Change, 2007b; Campbell-Lendrum, Corvalán, and Neira, 2007), and many of the



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