As people seek land to cultivate, wood to burn and raw materials for their industries, they turn to tropical forests - which are being destroyed at an unprecedented rate. Numerous economic, social, and ecological problems are being created by this loss and degradation and it is the world's poorest people who are the most severely affected.
Major repercussions of deforestation include: intensified seasonal flooding with resultant loss of lives and property; water shortages in dry seasons; accelerated erosion of agricultural lands; silting of rivers and coastal waters; the disappearance of plant and animal species; and local and regional climate modifications. In many tropical forests, the soils, terrain, temperature, patterns of rainfall and distribution of nutrients are in precarious balance and neither trees nor grasses will grow again once they are disturbed by extensive cutting. Even in those place where regrowth is possible, extensive clearance destroys the ecological diversity the original forest offered. The irony is that forest soils, once cleared, rapidly lose the few minerals they contain and are not suitable for continuous cropping.
The economic, ecological, social, and other costs to be paid for this loss are as yet unassessed. On the basis of the current rates of deforestation, it is plausible that natural tropical forests will largely disappear over the next 100 years. However their conversion into vast expanses of wasteland with little vegetative cover of economic value is not entirely improbable. These changes would imply extensive regional and global changes in climate.
Since pre-agricultural times, the world has lost 20% of its forest resources, with a reduction from 12 billion to 10 billion acres. In the past, most of forest losses were in the temperate forests of Europe, Asia and North America. In recent years, it is the tropical forests of Latin America, Asia and Africa that have been disappearing most rapidly.
In 1990 it was estimated that each year 16 to 20 million hectares (40 to 50 million acres) of tropical forest have been vanishing as trees are cut for timber and land is cleared for agricultural development. The rate of loss in 1987 was nearly 50% greater than in 1980. FAO has estimated that tropical forests are being removed at the rate of 7.3 million hectares per year.
According to a 1997 report of the World Wildlife Fund, 93 percent of the original Atlantic rain forest has disappeared, as well as 12 percent to 15 percent of the Amazon rain forest.
Brazil, with the largest remaining forest area, is losing more rainforest each year than any other country on the planet. 15,000 square kilometres of trees were cleared annually from 1978 to 1988; in preceding years, the annual clearance was 250% greater. Since 1988, 243,000 square kilometres have been deforested, the equivalent of 5% of the Brazilian Amazon, the largest rainforest in the world and is home to 30% of all animal and plant life on the planet. Information collated from satellite data in 2003 shows the speed of deforestation increased by 40% between 2001 and 2002 to reach its highest rate since 1995. More than 25,000 square kilometres of forest were cleared in single a year - mainly for large-scale soya farming.
In 1996, leaders of the ancient Mayan tribes of Belize were to take Britain to court over logging contracts they claim threaten their survival. The Belize government had approved large-scale logging in a 103,000-acre remote primary rainforest reserve near the Guatemalan border - on the advice of British officials. The Maya, who have depended on the forest for thousands of years to provide food, medicinal plants and building materials, say the logging will disrupt water supplies and bring unwanted roads and development to their homeland. Besides, it would drive away wildlife and cause huge social upheaval for the Mayans, most of whom are small-scale maize farmers. The Columbia River forest, which supports 1,500 plant species, 224 bird species and three unique frog species, is very humid, limestone tropical rainforest, unique in Central America.
In 1997, El Salvador ranked just behind Haiti as the Western Hemisphere's most deforested country. Only about 1.5 percent of its tropical forest cover was left, and about 7 percent more of the land was protected only somewhat by coffee trees. And even these trees were disappearing at an alarming rate. Most fuel was unavailable or extremely expensive, leaving wood the cheapest and most available means of cooking. The deforestation accelerated soil erosion, which in turn caused rivers to fill with sediment, killing water life.
Logging of Indonesia's rainforests is one of the most dramatic examples tropical deforestation. Indonesia is the world's largest exporter of plywood. Timber concessions are held by private companies to log specific areas. This system lacks incentives for the logging companies to preserve the land or provide for its future.
Tropical forests are the world's richest biological zones and are estimated to contain as much as 40% of all the terrestrial species on the planet. In addition, tropical forests produce a significant proportion of the world's oxygen and provide a wide range of useful products (fuelwood, building materials, pulpwood, food, pharmaceuticals, resins, gums, dyes) of economic significance for both developing and developed countries. Undisturbed tropical forests are also home to millions of the world's tribal peoples.
The increase in fires, while worrisome, did not result in an increase in deforestation in Brazil, although the two problems have risen in tandem.