Tropical forest trees, like all green plants, take in carbon dioxide and release oxygen during photosynthesis. Plants also carry out the opposite process—known as respiration—in which they emit carbon dioxide, but generally in smaller amounts than they take in during photosynthesis. The surplus carbon is stored in the plant, helping it to grow.
When trees are cut down and burned or allowed to rot, their stored carbon is released into the air as carbon dioxide. And this is how deforestation and forest degradation contribute to global warming. According to the best current estimate, deforestation is responsible for about 10 percent of all global warming emissions. (Where did that 10 percent figure come from?)
Why does deforestation occur? Forests are cleared to make way for any of a long list of agricultural products and other human activities. But UCS analysis shows that a majority of tropical deforestation occurring today can be traced to just four globally traded commodities: beef, soybeans, palm oil, and wood products.
Benefits of reducing deforestation
We need to protect tropical forests from deforestation and degradation if we want to reduce emissions to the levels needed to protect the planet against the worst global warming impacts. Ending deforestation will not solve global warming by itself, of course—urgent action is needed to cut the other 90 percent of emissions. But the problem cannot be solved if the role of tropical deforestation is ignored.
And reducing deforestation has other benefits beyond reducing global warming pollution. Tropical forests are home to many unique species of animals and plants. Animals such as the jaguar risk extinction if we do not act to protect their tropical forest habitat. In addition, tropical forests are crucial sources of food, medicine, and clean drinking water for people in developing countries. Tropical forests help regulate regional rainfall and prevent both floods and droughts. Reducing deforestation is not only a beneficial action against global warming—it also can make important contributions to saving biodiversity and supporting sustainable development.
The good news is that tropical deforestation can be reduced—and, in many places, already is being reduced. A variety of approaches, from corporate deforestation-free commitments to the REDD+ initiative to the Soy Moratorium, have shown promising results. Continuing progress will require a sustained commitment by governments, businesses, consumers, and non-governmental organizations to the goal of ending—and, where possible, reversing—tropical deforestation.