Much of this remaining area has been impacted by human activities and no longer retains its full original biodiversity.Today tropical rainforests are disappearing from the face of the globe. Despite growing international concern, rainforests continue to be destroyed at a pace exceeding 80,000 acres per day. Tropical cover now stands at 2 billion hectares, an area about the size of the United States plus China and representing around 13 percent of the world's land surface.