Deforestation refers to the loss or destruction of naturally occurring forests, primarily due to human activities such as logging, cutting trees for fuel, slash-and-burn agriculture, clearing land for livestock grazing, mining operations, oil extraction, dam building, and urban sprawl or other types of development and population expansion.
Logging alone—much of it illegal—accounts for the loss of more than 32 million acres of our planet's natural forests every year, according to The Nature Conservancy.
Not all deforestation is intentional. Some deforestation may be driven by a combination of natural processes and human interests. Wildfires burn large sections of forest every year, for example, and although fire is a natural part of the forest lifecycle, subsequent overgrazing by livestock or wildlife after a fire can prevent the growth of young trees.
How Fast is Deforestation Happening?
Forests still cover about 30 percent of the Earth's surface, but each year about 13 million hectares of forest (approximately 78,000 square miles)—an area roughly equivalent to the state of Nebraska, or four times the size of Costa Rica—are converted to agricultural land or cleared for other purposes.
Of that figure, approximately 6 million hectares (about 23,000 square miles) is primary forest, which is defined in the 2005 Global Forest Resources Assessment as forests of "native species where there are no clearly visible indications of human activities and where the ecological processes are not significantly disturbed."
Reforestation programs as well as landscape restoration and the natural expansion of forests have slowed the net deforestation rate somewhat, but the United Nations Food and Agriculture Organization reports that approximately 7.3 million hectares of forests (an area roughly the size of Panama or the state of South Carolina) are permanently lost every year.
Tropical rainforests in places like Indonesia, the Congo and the Amazon Basin are particularly vulnerable and at risk. At the current rate of deforestation, tropical rainforests could be wiped out as functioning ecosystems in less than 100 years.
West Africa has lost about 90 percent of its coastal rainforests, and deforestation in South Asia has been nearly as bad. Two-thirds of the lowland tropical forests in Central America have been converted to pasture since 1950, and 40 percent of all rainforests have been lost. Madagascar has lost 90 percent of its eastern rainforests, and Brazil has seen more than 90 percent of the Mata Atlântica (Atlantic Forest) disappear. Several countries have declared deforestation a national emergency.
Why is Deforestation a Problem?
Scientists estimate that 80 percent of all species on Earth—including those not yet discovered—live in tropical rainforests. Deforestation in those regions wipes out critical habitat, disrupts ecosystems and leads to the potential extinction of many species, including irreplaceable species that could be used to make medicines, which might be essential for cures or effective treatments of the world's most devastating diseases.
Deforestation also contributes to global warming—tropical deforestation accounts for about 20 percent of all greenhouse gases—and has a significant impact on the global economy. While some people may receive immediate economic benefits from activities that result in deforestation, those short-term gains cannot offset the negative long-term economic losses.
At the 2008 Convention on Biological Diversity in Bonn, Germany, scientists, economists and other experts concluded that deforestation and damage to other environmental systems could cut living standards for the world's poor by half and reduce the global gross domestic product (GDP) by about 7 percent.