A Biome is a community of plants and animals inhabiting a region defined by climate and dominant vegetation. For instance, a tropical rain forest is defined as an area having rapid tree growth and high species diversity made possible by high year-round temperature and high annual rainfall. Biome Viewer, a tool used in an earlier activity, uses a largely biological scheme for classifying biome. The Environmental Change Model (ECM) in Climate Reanalyzer, on the other hand, uses a hybrid classification scheme for planetary biomes, so it defines the climatic characteristics of each biome more precisely than Biome Viewer does. ECM also breaks the earth’s biomes down into more categories than the viewer does. For instance, ECM defines a tropical rainforest as a region where the average monthly temperature is 21°C or above year-round.
A major concern about present changes in global climate is the extent to which changes in regional climate affect life in the planet’s biomes. The concern here is not only about the scale of regional climate changes, but also how quickly those changes take place. As the climate of a biome changes its inhabitants must either adapt to the new conditions or migrate to areas where the new conditions are like what they are accustomed to. In the case of the latter, the ability of plants and animals to survive the transition depends on whether or not regional climates are changing slowly enough that these organisms can successfully migrate and that there are no geographic obstacles to their doing so. This is an issue not only for wildlife and forest management, but also for agriculture and public health. There is strong evidence that many international conflicts and human migrations are a result of crop failures and climate related dislocations.