A、Whether it can be detected and checked. B、Whether it will lead to widespread food shortage. C、Whether global warming will spee

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. There was renewed evidence that plants and animals are sensitive to climate. Since the Ice Age ended ten thousand years ago and warmer temperatures returned to the northern latitudes, many species have migrated north. If the predictions about the Greenhouse are correct, temperatures will rise by the same amount in the next one hundred years as they did in the past ten thousand years. Will animals and plants be able to adapt that quickly to the change in the environment? Many won’t. Certain species will probably become very rare. Experts say plants under climate stress will be very open to disease and fire. Forest fires may become more common. That, in turn, may harm animals that depend on the trees for food or for shelter. Any preserves we set up to protect endangered species may become useless as the species are forced to migrate along with their natural homes. Change is a part of life, but rapid change, says scientist George Wood Well, is the enemy of life.
Q:
19. What is the concern for ordinary people about the "Greenhouse Effect"?
20. What will be a possible threat to plants in the future?