FIGURE 6.22 Projected warming for the 21st century (difference between 2080-2099 temperature and 1980-1999 temperature) for the North American region using 21 different climate models, all using the same scenario of future GHG emissions. The mean (average) of the 21 model experiments is also shown in the bottom right panel. Several robust features are evident, including enhanced warming over land areas and higher latitudes. Differences among the 21 projections are indicative of some of the uncertainties associated with model projections. SOURCE: Christensen et al. (2007).