Dead acacia trees remain standing in a dry, cracked portion of Africa's Namib Desert. Because the desert is so dry, many well preserved human artifacts and ancient fossils can be found there.
Photograph from Natphotos/Getty Images
Growing Deserts
It's hard to imagine that global warming would have much effect on the world's already hot deserts. But even small changes in temperature or precipitation could drastically impact plants and animals living in the desert. In some cases global warming is predicted to increase the area of deserts, which already cover a quarter of Earth.
Human activities such as firewood gathering and the grazing of animals are also converting semiarid regions into deserts, a process known as desertification. Population growth and greater demand for land are serious obstacles in the effort to combat this problem.