31st May 2010

The main causes of deforestation are poverty (extension of subsistence farming), overpopulation and ignorance. The human population continues to increase exponentially, so does its need for fuelwood - 1/3 of the world population depends on it for cooking and heating.

Likewise, agriculture expands always further into forest land. The slash-and-burn method of subsistent farming is sustainable when populations are low, but very destructive when pressure on the land does not allow it time to recover. The forestry and timber trade have added another pressure on the forest, not so much by the selected trees they take out, but because less than 1% of fropical forests are exploited in a sustainable way involving sufficient re-planting.

Besides, lands opened for logging become accessible to hunters and agriculturalists, who move along the logging roads and soon convert the cleared forest to permanent cultivation. Much damage is also caused by grazing domestic livestock in tropical forests like in India, where 90 million of its 400 million cattle live now on forest land.


Deforestation is harmful to the earth and its inhabitants because trees absorb large amounts of carbon dioxide and, in turn, release oxygen for us to breathe and survive. The loss of forests is thus affecting the earth's ability to cleanse and freshen the air. It also means loss of biodiversity within the forest ecosystem. 50-90% of earth's 10 million species are believed to reside in tropical forests. At current rates of deforestation, 4-8% of rainforest species could be extinct by 2015, and 17-35% by 2040. This would mean the extinction of 20-75 species a day, the bulk of them unknown insects and other invertebrates. The precise consequences of such massive loss of potentially useful species are impossible to predict, but ecological patterns will certainly be severly disrupted.

Habitat - mostly forest- destruction is the main reason for the decline in primate populations. Some species, such as most marmosets and tamarins or ringtailed lemurs, manage to survive the destruction of their forest habitat by adapting. They feed on the crops planted in the cleared land and later learn to live in the secondary forest, which springs up when the old soil becomes exhausted for agriculture and man moves on to clear the next area of primary forest. But the logging business, in particular, along with the "bush meat" trade it allows, means death for most primates, notably thousands of gorillas, chimpanzees, and orang utans. As human numbers continue to rise, the pressure to build on or cultivate every patch of "unused" land mounts. Only if we human primates can reverse this trend will the non-human primates have a future. Today, all the apes are on the endangered species list along with many monkeys and most lemurs. All non-human primates will soon be forced into extinction, unless steps are taken now to protect them and their habitat, notably the tropical forests. Meanwhile, deforestation goes on: in the 5 minutes it took you to read through this page, another 250 hectares of tropical forests have been destroyed.