DEFORESTATION

It would be difficult to imagine life without the beauty and richness of forests. But scientists warn we cannot take our forests for granted. By some estimates, deforestation has already resulted in the loss of as much as eighty percent of the natural forests of the world. Currently, deforestation is a global problem, affecting wilderness regions such as the temperate¹ rainforests of the Pacific Northwest area of the US and Canada's British Columbia, and more seriously, the tropical rainforests of Central and South America, Africa, Southeast Asia, and Australia.

Deforestation occurs for many reasons. In the temperate rainforests of the US and Canada, large areas of forest have been cleared for logging² and urban expansion. In tropical rainforests, one of the most common reasons for deforestation, aside from logging, is agriculture. Because the soil in many tropical regions is often nutrient-poor, and since ninety percent of nutrients in tropical forests are found in the vegetation and not in the soil, many farmers practice an agricultural method known as slash³ and burn. This method consists of cutting down the trees of an area in the rainforest and burning them to release their rich nutrients into the soil.

This method is sustainable only if the population density does not exceed four people per square kilometer of land. When this is the case, each farm has enough land to let sections of it lie fallow⁴ for ten years or more, which is enough time for the land to renew itself. In recent years, however, the population density has often reached three times the optimum⁵ number. This results in land being used in a more intensive manner with no chance to recover. Under these conditions, slash-and-burn farming becomes only a temporary solution. Within two or three years, the soil becomes depleted⁶, and the farmer must repeat the slash- and-burn process elsewhere.

Deforestation also causes changes in the Earth's atmosphere. For example, deforestation in tropical areas disrupts the cycle of rain and evaporation⁷ by removing the moist canopy⁸ of foliage⁹ that trees provide. Undisturbed, this canopy traps about twenty percent of the precipitation in the area; when this moisture evaporates, it causes clouds to form, promoting future precipitation. When trees are cleared away, the canopy is lost, and the cycle is disturbed. Rainfall sinks into the earth rather than evaporating into the air, leading to a drier local environment. This can lead to desertification—the forming of deserts and ultimately to rises in atmospheric temperatures.

Deforestation is also partially responsible for rising atmospheric levels of carbon dioxide (CO2). Forests normally decrease the amount of carbon dioxide because the trees consume it and release oxygen. Less forest, therefore, means more CO2 in the atmosphere, especially when trees are burned, which releases even more CO2. About 1.6 billion metric tons of CO2 enter the atmosphere this way every year. For comparison, the burning of fossil fuels releases approximately thirty-three billion metric tons of CO2 per year. These rising levels are a cause for concern because they are expected to be responsible for fifteen percent of the increase in global temperatures up through 2025.

In addition, deforestation causes the extinction of thousands of species of wildlife annually. It is estimated that as many as eighty million kinds of animals and plants make up the total species on Earth, but only about 1.5 million have been studied and named by scientists. Tropical rainforests, which cover about seven percent of the Earth's land, are home to over half of these plant and animal species. If the rainforests disappear, many of these species will become extinct. This means many species will vanish¹⁰ before we can discover them.

Is it possible to reverse the devastating effects of deforestation? Many experts think so, but it will require a concerted international effort to protect the remaining forests. It will also require increased awareness, more sustainable consumer habits, and solutions that replace financial incentives for local economies.

• per square kilometer
• climate change
• remain undiscovered
• have vanished
• species extinction
• trapped the rainfall

• agriculture
• intensive
• precipitation
• sustainable 
• tropical
• vegetation

The High Price of Beef

Ranching has become a major cause of deforestation in Central and South America. Since cattle ranching is very inexpensive in Costa Rica—it is about fifty percent cheaper than in the United States, for example-many foreign companies have purchased large areas of land there. They keep their cattle in Costa Rica and then export the beef to other countries, mainly the US. In order to establish grasslands for grazing, they clear forests away completely. These artificially manufactured pastures remain productive for six to eight years, after which they are abandoned. The forest is lost forever.

In Brazil, where over eighty percent of the farmable land is held by less than five percent of landowners, a large number of poor farmers move into rainforest areas just to survive. Like farmers in Costa Rica, many of these farmers raise beef that is sold mainly to fast-food hamburger chains. These fast-food chains can keep their prices low because they buy beef cheaply from Central and South American cattle ranchers. But the hidden costs of the beef include the environmental impact: deforestation and rising global temperatures.

Some experts believe that social practices that focus on profit at the expense of environmental balance raise important questions about the values and belief systems that support them. For example, it has been suggested that the belief in humans' superiority to animals promotes an attitude that may excuse the domination of the environment in the service of human comfort and progress.