Forests are critical ecosystems that cover about 30% of the Earth. They provide wildlife habitat; filter water and air; and provide building materials, food, fuel and medicine for humans. Forests also hold the rich histories of indigenous peoples and profoundly shape the cultures and societies that grow out of and around them. At a time when anthropogenic (human-originating) climate change is driving changes and hazards around the world, forests also help to regulate the global carbon cycle, storing as much as 45% of terrestrial carbon.