Deforestation refers to the clearing of forests, usually at such a rapid rate that it is impossible for the forests to regenerate naturally in a short time. Deforestation brings benefits to humans by clearing land that can be used for settlement, to make space for a growing population to live in. However, it also brings harm to humans because eroded topsoil from deforested areas can flow into rivers, causing them to become silted and flood more easily. Also, the clearing of forests with methods such as burning trees down will lead to air pollution.
Deforestation is beneficial to humans because it creates more areas for the creation of settlements. Rapidly growing populations require more space to live in, to prevent overpopulation. New settlements (i.e. housing and social facilities) can be built upon empty, open spaces created through the clearing of previously forested (and uninhabitable) areas. People can move into these new settlements, instead of overpopulated and overcrowded areas where living conditions are less desirable (i.e. lesser space, lesser availability if services and facilities). An example of how deforestation benefits humans in this way can be seen in Kalimantan. The city of Balikpapan is one of the largest in Kalimantan, and had a population of 400000 in 2005. As a result of the growth of this city, the settlement of Balikpapan has expanded into a protected forest adjacent to it to prevent overcrowding in the city.
On the other hand, deforestation brings harm to humans because it can lead to erosion of the topsoil and siltation of rivers near the deforested areas. The tree canopy of a rainforest provides shelter from rain for the soil, and the roots help hold the soil in place. This helps to prevent the topsoil from being washed away by the rain. However, when a forest is cleared, the tree canopy