Global Warming

If we can reduce the greenhouse gases going into the atmosphere, we probably can slow the rate of global warming and climate. There are a number of things that we can do to prepare for the changes that are coming. If we act now, perhaps we can "soften the blow" of the greenhouse effect. In the future, the weather cold change much more dramatically from year to year than it does now. As global warming alters habitats, many kinds of animals will be on the move, but all sorts of barriers will stand between them and a new place to live. To help animals get around these barriers, it might be necessary to set up migration corridors that connect natural areas with one another. Without human intervention, many kinds of plants also may not survive as the earth's climate changes. Forests, in particular, may need our help. If climate changes come rapidly, few tree species will be able to spread into new areas fast enough to keep up with changing conditions.

Glaciers are large, thick masses of slow-moving ice that persist from year to year. They cover about a tenth of the earth's land surface. The vast ice sheets of Antarctica and Greenland account for most of this area. Smaller ice caps are found in Scandinavia, Caffin Island, Iceland, and elsewhere. In addition, there are tons of thousands of valley glaciers that follow stream channels down mountain slopes. All together, glaciers contain about seventy-five percent of the available fresh water of the earth. Because global warming is expected to be greatest in polar and temperate regions, scientists expect the glaciers to melt more rapidly than they do today. An executive summary of a United Stations survey published in 1990 concluded that if worldwide "business as usual" continues, the resulting global temperature increased would produce mean sea-level rise of about twenty-five inches by the end of the next century. Other studies predict such increases will occur as soon as 2040. Much depends on how fast the polar ice...