Deforestation of tropical rainforests that is caused by many things, including over‐intensive shifting cultivation, the collection of fuelwood for cooking and heating and for making charcoal, encroachment and clearance by landless peasant farmers, clearance for pasture or crops, commercial logging, grazing, road construction, ranching, mining, and fire. Ecologists are concerned at the pace and pattern of the clearance of tropical rainforest, which once covered about a tenth of the Earth's surface. More than 40% of the rainforest has been cleared since the 1940s, and clearance continues at a rate of about 200 000 square kilometres a year. Less than 1% the Brazilian Amazon had been cleared before 1975, but between 1975 and 1987 the rate of clearance increased exponentially. Overall, about a quarter of the loss is due to forestry, but the balance of factors varies from place to place. Much of the wood felled from rainforests is destined for the international timber market, where tropical hardwood commands a high price. Ecologists argue that if clearance continues at recent rates all of the world's primary (undisturbed) rainforest is likely to disappear or be damaged by 2020. This would mean the loss of an irreplaceable biological asset—rainforests contain about half of all the wood growing on the Earth and at least 40% of all known species of plants and animals. They are amongst the most diverse and complex ecosystems on the planet. As well as a significant loss of biodiversity, clearance of rainforests causes the loss of valuable natural resources including hardwoods (such as mahogany, rosewood, and teak) and tree products (such as quinine, vegetable gums, and rubber). Tropical rainforest clearance may also contribute to the greenhouse effect and global warming, by removing an important carbon sink. Various attempts have been made to conserve the remaining rainforests. For example, some governments (including those of Costa Rica, Panama, Brazil, and the Democratic Republic of the Congo) have designated forest reserves to conserve representative tracts of this important biome, and some endangered tropical hardwood species have been listed in the Convention on International Trade in Endangered Species (CITES).
Subjects: Environmental Science.