Forests cover around a quarter to a third of the total land surface of the Earth. The reduction in area of this valuable environmental, social and economic resource through deforestation has the potential to cause problems on a global scale. Climate models have demonstrated a clear link between deforestation and climate change.
Deforestation is the process of changing land use from forestry to a non-forest use. Western Europe has already lost over 99% of its primary forest. Today, deforestation programmes focus on the major rainforests of the tropics. In the 1980s global deforestation was estimated at 17 to 20 million hectares per year, equivalent to the size of Britain. Current tropical tree planting programmes are not keeping pace with this rate of deforestation. Countries in these areas are often under-developed and striving for improved economies. Deforestation for wood and agricultural land can provide numerous economic benefits, but can have damaging environmental impacts on forest ecosystems and can affect local and regional climate.
Forests absorb a lot of sunlight for photosynthesis, and only about 12 to 15% is reflected. The large amounts of energy absorbed by forests acts to stimulate convection currents in air which enhance the production of rainfall. Tropical rainforests in particular are very wet and humid places. Deforested areas, by contrast, reflect about 20% of incoming sunlight. Deforested areas consequently, can become drier as a result of the loss of vegetation, increasing the risk of desertification. As the area of deforestation increases, so the impact on climate grows.
Trees also absorb carbon dioxide from the atmosphere for photosynthesis, and therefore help to regulate the natural greenhouse effect. Deforestation takes away a potential sink for the carbon dioxide mankind is pumping into the atmosphere. In addition, if forests are removed by burning, a lot of extra carbon dioxide locked up in tree wood is returned to the atmosphere.