Shrinking Biomes

Most of the Earth’s major biomes have shrunk rapidly in the last 200 years. At one time, forest covered about 40 percent of the Earth’s surface. But about half of all tropical rainforest have now been destroyed. Only 30 percent of tropical dry forests remain. Only 25 percent of grasslands, which once covered one third of the Earth, have survived. The only expanding biome is deserts.