deforestation

Timber extraction in a Russian forest. Large swathes of mixed and deciduous forest have been cleared to make way for agriculture, and to supply pulp and lumber mills.

Forest clearance in Guatemala. While some timber is exported, most of the cut wood is used domestically for fuel.

Rainforest clearance and banana trees, Dominica. The destruction of rainforest for timber and fuel, its clearance for agricultural land, and the effects of extractive industries, cause soil erosion, drought, and the destruction of wildlife and their habitats.

Rainforest clearance and banana trees. During the period 1990–95, the process of deforestation in South America alone resulted in the loss of 24 million ha/59 million acres of tropical rainforest.

Destruction of forest for timber, fuel, charcoal burning, and clearing for agriculture and extractive industries, such as mining, without planting new trees to replace those lost (reforestation) or working on a cycle that allows the natural forest to regenerate. The rate of deforestation is of major environmental concern as irreversible damage is being done to the habitats of plants and animals. Deforestation ultimately leads to famine, and is thought to be partially responsible for the flooding of lowland areas, since trees are needed to help slow down water movement.

Deforestation causes fertile soil to be blown away or washed into rivers, leading to soil erosion, drought, flooding, and loss of wildlife, and consequently affecting the biodiversity (biological variety) of ecosystems. It may also increase the carbon dioxide content of the atmosphere and intensify the greenhouse effect, because there are fewer trees absorbing carbon dioxide from the air for photosynthesis.

The first deforestation occurred more than two thousand years ago in areas surrounding the Mediterranean as wood was increasingly used for fuel, building materials, and the construction of ships. Throughout the next two millennia most of the woodland in Europe was destroyed as human demands increased. The current wave of deforestation in the tropics dates back only to the 1970s, but even so has reduced the amount of intact forest ecosystem from 34% of total land in the affected areas to 12%. Deforestation in the tropics is especially serious because such forests do not regenerate easily and because they are such a rich source of biodiversity.

The United Nation's Food and Agriculture Organization (FAO) estimated that 137,000 sq km/53,000 sq mi of tropical forests were destroyed during each year of the 1980s, and that the deforestation rate for the tropics between 1990 and 1995 was 130,000 sq km/50,000 sq mi a year. A FAO survey showed that the area covered by mangrove forest had fallen to below 15 million hectares by the end of 2000 and that the deforestation rate was still 1% per annum.

Global deforestation continues to rise despite international efforts to control the situation. The rate of deforestation in the Amazon rainforest alone rose by 40% in 2002–03.