These forests were never extensive. About 30 million hectares of temperate rainforest once covered an area only 4 percent of the size of today's tropical rainforest. The areas that remain are highly productive as well as diverse, playing a critical role in maintaining the health of the coastal watersheds. The environmental and economic impacts of the loss of temperate rainforests are widespread. As these habitats decline, so do the sectors of the economy that depend on healthy forests and fisheries.
Coral reefs are under severe pressure from a variety of threats.
By the year 2000, approximately 1 billion people will live in coastal cities. Islands Because their evolution takes place in relative isolation, many islands are home to species that are found nowhere else. However, the fixed boundaries and endemic species of islands also put them at great risk of species extinction. The introduction of nonnative species can be an especially serious threat to islands. On Guam, the brown tree snake has caused the extinction of three of the island's five endemic bird species and has nearly eliminated the other two.