While man adapts to a changing climate he has created, the natural world will suffer great losses. It has been estimated that for each Fahrenheit degree of global warming, temperature zones will move northward (in the northern hemisphere) about 50 miles.[Challenge of Global Warming,Abrahamson,Island Press, 1989] Just as it will not be possible to grow certain domestic crops like corn in the mid and southern sections of the US, wild species of plants and animals at a given latitude will have to move northward, if they are to survive. 'Making the move' presents unique problems for both native plants and wild animals.
Plants can only migrate at a rate determined by the area size where they disperse their seeds and the reproductive cycle of an individual plant. If the climate zone necessary for life is moving faster that one generation of trees can spread its seeds, that type of tree will not survive the radical move northward.
For both plants and animals, there is the additional problem of barriers to cross during a move. These can be both natural, such as rivers, canyons, lakes, or they may be manmade, such as metropolitan areas, or large sections of irrigated, cultivated agricultural land.
Wild animals have to compete with domestic cattle and sheep on open range land, and may be forced into areas that have already been changed by man to such an extent that there is no place for them to live, and no food supply. Because national parks and wildlife refuges have fixed boundaries that will not move, animals in these ecosystems will surely suffer if they attempt to migrate outside the protected boundaries.
The oceans' coral reefs may be dying as a result of warmer seas. According to the Washington Post, Oct. 12, 1990, when coral is exposed to warmer water, a 'bleaching' action occurs. The bleaching is the result of the loss of an algae inside the coral polyps. Without the symbiotic relationship of the algae, the coral becomes weak and dies. 'Bleaching' reports used to be rare and isolated, but major episodes of bleaching have occured on many reefs at several times during the 1980's. ***
