Many of the world's forests, especially in the tropics (the areas closer to the equator), are disappearing because of increased pressure of more people using the land. Deforestation is a problem because trees absorb carbon dioxide and release oxygen, and forests provide habitats for many of the Earth’s species.

Tropical deforestation occurs for a number of reasons, including clearing land for agricultural purposes and commercial logging.

Farmers in many tropical countries clear land to plant crops by cutting down the trees in a small area and burning the tree trunks. This process is called "Slash and Burn." After the burned debris is cleared away, the farmer plants his crops. The problem with this agricultural practice is that the nutrients (chemicals that provide nutrition for plants to grow) in a tropical forest are mostly in the tree trunks, stems, branches, leaves, surface roots and leaf litter, not deep down in the soil as needed by most food crops.

After a few years, the small amount of nutrients available are used up, the farmer's crops become less productive, and then the farmer moves on to another patch of forest to slash and burn. Farmers also clear land to graze cattle, then must clear more land when the grass doesn't grow after a few years because of the poor nutrient value of the soil. Cattle and other livestock are very damaging to forest soils because their sharp hooves dig into and destroy the roots, and their weight compacts and hardens the soil. Often these farmers are so poor, they must keep on with this practice in order to survive.

Commercial logging can be more or less damaging to the forest, depending on how it is done. Clear cutting is the most damaging, because it takes down all of the trees. However, selective logging can be almost as damaging although it only takes the most valuable tree species. The heavy logging trucks, bulldozers and other equipment can do an enormous amount of damage to the surrounding forest as the loggers build roads to get to and take out the timber.
The Amazon region of Brazil has had a very large amount of deforestation during the last part of the last century. In the 1970s and 1980s, the Brazilian government encouraged poor landless Brazilians to claim ownership of land in the Amazon region by settling on it and farming it (even though the land was not productive for farming). Because of this, the rate of deforestation in the Brazilian Amazon was 6200 square miles per year from 1978-1986. By 1988, 6%, or 90,000 square miles (the size of New England), of the Brazilian Amazon had been cut down. As much as 230,000 square miles (the size of Texas) was affected by the deforestation.

Tropical deforestation has long-range and possibly dangerous consequences. Trees contain about 50% carbon. When trees are cut down and burned, the carbon combines with oxygen and is released into the atmosphere as carbon dioxide. Carbon dioxide is one of the greenhouse gases that contribute to global warming and climate change.
Tropical rain forests are an important part of the global water cycle, which is also known as the global hydrologic cycle. Evaporation and other processes from the trees and plants in the tropics return large amounts of water to the atmosphere, causing cooling, cloud formation and precipitation (rain). When the forest is destroyed, the cooling effect is taken away, cloud formation and precipitation patterns can be affected, and the sun's energy can heat the earth's surface more.

Tropical rain forests cover only 7% of the Earth's surface, yet they are rich in biodiversity, containing over half of Earth's plant and animal species. Many of the rain forest species can only exist in a specific habitat, so when that habitat is destroyed by deforestation the species may become extinct. Some of the tropical plant species are very important to medicine, and we may be losing species that could lead to a cure for cancer or other serious diseases.

Another bad effect of deforestation is that native Indian people may lose their lands and have nowhere to go. Many native peoples live off of the products of the forest, and have no way of supporting themselves outside of the forest.

Although the rate of deforestation in the Brazilian Amazon has slowed since the 1970s and 1980s, tropical forests around the world, including in Africa and Asia, are still under threat of disappearing. In order to stop deforestation, governments must develop better methods of farming and commercial logging, and improve the living conditions of the poor people often responsible for deforestation. There are many organizations, such as The Rainforest Network, that work very hard to preserve tropical forests. We need to be aware of the serious problems in all areas of the world and help find the solutions.