Deforestation & Its Effects on Climate Change

Carbon from Burning

• When forests are cut down, the wood is often not used in a constructive manner but burned for little or no purpose. Slash-and-burn farming, for example, is a popular technique for clearing agricultural space where forests are cut down and then burned. The ash helps fertilize the soil, but often the soil of the land that was cleared is unsuitable for farming after a few years, and farmers will then carve a new swath of agricultural land out of the forest, leaving deforested and nutritionally depleted soil in their wake.

Less Carbon Uptake

• Forests are also a large contributor to the process known as biosequestration, which is the capture and storage of carbon dioxide by living plants. A living forest can sequester huge amounts of carbon dioxide in this way, but when the forest is cut down that capacity dies with it and less carbon can be drawn out of the atmosphere through biosequestration. This then means that there is a greater total of carbon in the atmosphere contributing to global warming.

Tipping Points

• Deforestation can also cause ecosystems to go past tipping points, after which positive feedback loops take control and the ecosystem is radically altered no matter what humans do. The Amazon rain forest, for example, is thought to have a tipping point that exists at about 20 percent deforestation, according to a World Bank Studies report. After that 20 percent mark is reached, positive feedback loops take over and a projection from that same report states that the Amazon will reach a new equilibrium as a Savannah-type ecosystem. As of November, 2010, which is when the report was published, Amazon deforestation stood at around 17 to 18 percent.

Effects on Other Natural Systems

• Deforestation also effects global warming indirectly by having effects on other natural systems. When trees are removed, for example, it reduces the water content of the soil. The soil dries out, which can lead to less cohesive soil, desertification, floods and land slides. With environmental issues like deforestation it is necessary to take a broad look at how other natural systems may be affected. The environment is highly interconnected, and something like deforestation never happens in isolation.