Forests currently cover approximately 30 percent of the Earth's land surface. Each year, however, chunks of forest that amount to the size of Panama, according to "National Geographic" magazine, are destroyed in unsustainable ways for agriculture and to provide raw materials for manufacturing. The clearing of forests on a large scale, known as deforestation, has far-reaching consequences for humans and animals, ranging from habitat loss to climate change.
Losing the Forest and the Trees
Irresponsible slash-and-burn agriculture, which entails using fire to clear forests for growing crops and grazing cattle, is a major cause of deforestation around the world, particularly in tropical areas like the island of Madagascar. When done improperly or in excess, slash-and-burn agriculture destroys forests permanently in exchange for just a few years of fertile soil. Illegal logging -- cutting down more trees for timber than is sustainable and allowed by law -- is also largely to blame for global deforestation.
Some 80 percent of the world's terrestrial plants and animals depend on forests for food, water and shelter. Tropical rain forests are especially diverse; South America's Amazon alone harbors 10 percent of the planet's biodiversity. As a direct consequence of deforestation, many animal species, including a variety of primates, are on the verge of extinction. The orangutan, a great ape found in tropical rain forests on the Southeast Asian islands of Sumatra and Borneo, the giant panda of China's bamboo forests and the maned three-toe sloth, which occurs exclusively in Brazil's Atlantic rain forests, are examples of species endangered as a result of deforestation.
People Pay the Price
The estimated 1.6 million people worldwide who depend on forests for their livelihood are directly impacted by deforestation. Included in that number are 60 million people who earn a living from forest-based industries and 300 million people, among them indigenous cultures, that live in or close to forests. Indigenous peoples often subsist by hunting and gathering forests plants and animals. Moreover, the United Nations calculates that more than 25 percent of pharmaceutical drugs are derived from substances found in tropical rain forest plants. Destroying forests, therefore, can potentially eliminate cures for human ailments.
Under the Weather
Forests, especially the tropical variety, are metaphorically called the lungs of the Earth because they remove carbon dioxide from the air and release oxygen through photosynthesis -- the process by which the chlorophyll cells of green plants convert solar energy into nourishment. Forests are also thought of as "sinks" through which carbon dioxide is removed from the atmosphere. Less tree cover translates into increased atmospheric levels of carbon dioxide, a greenhouse gas that plays a key role in climate change. Fluctuations in environmental temperatures caused by carbon dioxide-fueled climate change can be detrimental to many plant and animals species.
- World Wildlife Fund: Threats - Deforestation
- National Geographic: Deforestation
- World Wildlife Fund: Forests, Air & Climate
- World Wildlife Fund: Forests, Jungles, Woods and Their Trees
- World Wildlife Fund: Forests as Habitat
- World Wildlife Fund: Species - Giant Panda
- University of Michigan Animal Diversity Web: Maned Three-Toed Sloth
- UNESCO: Natural Sciences - Protecting Biodiversity, Protecting Forests
- United Nations Environment Programme: The Relationship Between Indigenous People and Forests
- NA/Photos.com/Getty Images