If the earth gets hotter in the new century, what will happen to animals and the plants which animals depend on for survival? The question offers another way of looking at the greenhouse effect. People have talked about the general problem of global warming for some time. But they were usually worried about things like whether to buy a home on the coast. Biologists and other scientists turn their attention to plants and animals at an important meeting that took place last October. They reviewed evidence that plants and animals are sensitive to climate. Since the Ice Age ended 10,000 years ago and warmer temperatures returned to the northern latitudes, many species have migrated north.