The greatest cause of tropical rainforest destruction today comes from human activities, which, unlike natural damage, are unrelenting and thorough. Although most of this deforestation is driven by national and international economic forces, a significant proportion serves no long-term purpose; it results from subsistence activities on a local level. Many of the effects from human-induced destruction of the rainforests are probably irreversible within our time.
The role of humans in the deforestation of the world's forests is considerable and extensive. Many activities contribute to this loss including subsistence activities, oil extraction, logging, mining, fires, war, commercial agriculture, cattle ranching, hydroelectric projects, pollution, hunting and poaching, the collection of fuel wood and building material, and road construction. Under current practices, extractive industries (timber, oil, and mineral) promote the development of short term booms that encourage settlement. These booms and resulting settlements can attract large numbers of poor seeking a better life. They clear the surrounding land for agriculture and livestock. Meanwhile, the forest resource, whether it be oil, timber, or minerals, is rapidly depleted with little consideration for the long-term consequences. Once the resource is exhausted, developers move on to new areas, leaving behind a degraded environment and settlers with few livelihood options. Where forest remains, it may be cleared for subsistence agriculture. Most extractive processes in the rainforest are not sustainable as currently practiced.
Like most environmental assets, rainforests are endangered by their status as open-access resources or as common property. (Designating rainforests as open-access resources is not entirely accurate, in light of the lack of formal property rights in certain countries and the limited capacity of many governments to manage and regulate the rainforest lands. However, treating rainforest as such is adequate for this discussion). Under open access, no group has exclusive use of rainforest resources, but essentially everyone enjoys access to the resource. There is little incentive for conservation with the mentality of "If I do not get the resource someone else will," and forest is depleted by industry and small farmer alike. In addition, economic incentives like subsidies and tax breaks for forest developers distort the direct costs of harvesting and converting tropical rainforests. The result is market failure, where the prices for tropical timber products and other goods derived from rainforest destruction do not reflect the full environmental costs of the loss of goods and services provided by the ecosystem. Therefore, by offering these incentives, the government effectively makes it profitable for firms to convert forest for development purposes where it normally would not be profitable. A good example of this is the pulp and paper industry in Indonesia. The Ministry of Forestry grants large supplies of cheap fiber in the form of large forest concessions to pulp and paper companies. The companies don't have to pay for the "externalities" like carbon emissions, biodiversity loss, or water pollution. Instead it is society as a whole that bears the costs.
In the 1980s and 1990s another contributor to commercial forest destruction was the outstanding debts of developing countries, which caused them to seek quick ways to raise revenue to make debt payments. This is diminishing in importance today.
However, the fundamental underlying cause of deforestation is population growth, both in developing countries, which depend on forest lands for sustenance, and in developed countries, which demand products made from forest resources.
We humans have always cleared the forest for our own interests, but in the past, the process was slow and only limited regions were deforested, generally for subsistence agriculture. Today humanity is far more efficient at clearing the forest and the push for short-term profit is a powerful motivator for forest conversion.
Deforestation for palm oil production in Malaysian Borneo. Click image for more information. (Photo by R. Butler)