Lester R. Brown
Chapter 5. Natural Systems Under Stress: Shrinking Forests: The Costs
In early December 2004, Philippine President Gloria Macapagal Arroyo “ordered the military and police to crack down on illegal logging, after flash floods and landslides, triggered by rampant deforestation, killed nearly 340 people,” according to news reports. Fifteen years earlier, in 1989, the government of Thailand announced a nationwide ban on tree cutting following severe flooding and the heavy loss of life in landslides. And in August 1998, following several weeks of record flooding in the Yangtze river basin and a staggering $30 billion worth of damage, the Chinese government banned all tree cutting in the basin, home to 400 million people. Each of these governments had belatedly learned a costly lesson, namely that services provided by forests, such as flood control, may be far more valuable to society than the lumber in those forests. 6
At the beginning of the twentieth century, the earth’s forested area was estimated at 5 billion hectares. Since then it has shrunk to 3.9 billion hectares—with the remaining forests rather evenly divided between tropical and subtropical forests in developing countries and temperate/boreal forests in industrial countries. 7
World forest loss is concentrated in developing countries. Since 1990, the loss in these nations has averaged 13 million hectares a year, an area roughly the size of Kansas. Overall, the developing world is losing 6 percent of its forests per decade. The industrial world is actually gaining an estimated 3.6 million hectares of forestland each year, principally from abandoned cropland that is returning to forests on its own, as in Russia, and from the spread of commercial forestry plantations. 8
Unfortunately, even these official data from the U.N.’s Food and Agriculture Organization (FAO) do not reflect the gravity of the situation. For example, tropical forests that are clearcut or burned off rarely recover. They simply become wasteland or at best scrub forest, yet they are still included in official forestry numbers. Plantations, too, count as forest area, yet they also are a far cry from the old-growth forest they sometimes replace.
The World Resources Institute (WRI) reports that of the forests that do remain standing, “the vast majority are no more than small or highly disturbed pieces of the fully functioning ecosystems they once were.” Only 40 percent of the world’s remaining forest cover can be classified as frontier forest, which WRI defines as “large, intact, natural forest systems relatively undisturbed and big enough to maintain all of their biodiversity, including viable populations of the wide-ranging species associated with each type.” 9
Pressures on forests continue to mount. Use of firewood, paper, and lumber is expanding. Of the 3.34 billion cubic meters of wood harvested worldwide in 2003, over half was used for fuel. In developing countries, fuelwood accounts for nearly three fourths of the total. 10
Deforestation to supply fuelwood is extensive in the Sahelian zone of Africa and the Indian subcontinent. As urban firewood demand surpasses the sustainable yield of nearby forests, the woods slowly retreat from the city in an ever larger circle, a process clearly visible from satellite photographs taken over time. As the circles enlarge, the transport costs of firewood increase, triggering the development of a charcoal industry, a more concentrated form of energy with lower transport costs. March Turnbull writes in Africa Geographic Online: “Every large Sahelian town is surrounded by a sterile moonscape. Dakar and Khartoum now reach out further than 500 kilometers for charcoal, sometimes into neighboring countries.” 11
Logging for lumber also takes a heavy toll, as is most evident in Southeast Asia and Africa. In almost all cases, logging is done by foreign corporations more interested in maximizing a one-time harvest than in managing for a sustainable yield in perpetuity. Once a country’s forests are gone, companies move on, leaving only devastation behind. Nigeria and the Philippines have both lost their once-thriving tropical hardwood export industries and are now net importers of forest products. 12
Forest losses from clearing land for farming and ranching, usually by burning, are concentrated in the Brazilian Amazon, the Congo basin, and Borneo. After having lost 97 percent of its Atlantic rainforest, Brazil is now destroying the Amazon rainforest. This huge forest, roughly the size of Europe, was largely intact until 1970. Since then, 20 percent of it has been lost. 13
The fast-rising demand for palm oil led to an 8-percent annual growth rate in the palm plantation area in Malaysian Borneo (Sarawak and Sabah) between 1998 and 2003. In Kalimantan, the Indonesian part of Borneo, growth in palm oil plantings is higher, at over 11 percent. Now that palm oil is emerging as a leading biodiesel fuel, growth in its cultivation will likely climb even faster. The near-limitless demand for biodiesel now threatens the remaining tropical forests in Borneo and elsewhere. 14
Haiti, a country of 8 million people, was once largely covered with forests. Now there are forests standing on scarcely 2 percent of its land largely because trees are cut for firewood. In September 2004, tropical storm Jeanne left 1,500 dead and over 1,000 more missing and presumed dead. With the trees gone, the soil had washed away and there was little left to hold the downpour. Once a tropical paradise, Haiti is now a case study of a country committing ecological and economic suicide. As its forests have shrunk and its soils have eroded, Haiti has been caught in an ecological/economic downward spiral from which it has not been able to escape. It is a country sustained by international life-support systems of food aid and economic assistance. 15
Haiti is a classic case of overshoot and collapse. First the trees go, then the soil, and finally the society itself. Without food from abroad, Haiti’s population might now be declining as a result of hunger. Haiti is a microcosm of what much of the earth will be like if deforestation continues.
Scores of countries are suffering from disastrous flooding as a result of deforestation. In 2000, Mozambique was partially inundated as the Limpopo overflowed its banks, taking thousands of lives and destroying homes and crops on an unprecedented scale. The Limpopo river basin, which has lost 99 percent of its original tree cover, will likely face many more such floods. 16
The biologically rich rainforest of Madagascar is also disappearing fast. As the trees are cut either to produce charcoal or to clear land in order to grow food for the island’s increasing population, the sequence of events is all too familiar. Environmentalists warn that Madagascar could soon become a landscape of scrub growth and sand. 17
While deforestation accelerates the flow of water back to the ocean, it also can reduce the recycling of rainfall inland. Some 20 years ago, two Brazilian scientists, Eneas Salati and Peter Vose, pointed out in Science that when rainfall coming from clouds moving in from the Atlantic fell on healthy Amazon rainforest, one fourth of the water ran off and three fourths evaporated into the atmosphere to be carried further inland to provide more rainfall. When land is cleared for grazing or farming, however, the amount that runs off and returns to the sea increases dramatically while that which is recycled inland falls alarmingly. 18
Ecologist Philip Fearnside, who has spent his career studying the Amazon, observes that the agriculturally prominent south-central part of Brazil depends on water that is recycled inland via the Amazon rainforest. If the Amazon is converted into a cattle pasture, he notes, there will be less rainfall to support agriculture. 19
A similar situation may be developing in Africa, where deforestation and land clearing are proceeding rapidly as firewood use mounts and as logging firms clear large tracts of virgin forests. In Malawi, a country of 13 million in East Africa, forest cover has shrunk from 47 percent of the country’s land area to some 28 percent in a matter of years. The cutting of trees to produce charcoal and to cure tobacco is leading to a sequence of events paralleling that in Haiti. 20
As the trees disappear, rainfall runoff increases and the land is deprived of the water from evapotranspiration. Consulting hydrogeologist Jim Anscombe notes: “Driven by energy from the sun, the trees pump water from the water table, through the roots, trunk and leaves, up into the process of transpiration. Collectively the forest pumps millions of liters of water daily to the atmosphere.” Given the local climate conditions, this evapotranspiration translates into summer rainfall, helping to sustain crops. When the forests disappear, this rainfall declines and crop yields follow. 21
More and more countries are beginning to recognize the risks associated with deforestation. Among the countries that now have total or partial bans on logging in primary forests are China, New Zealand, the Philippines, Sri Lanka, Thailand, and Viet Nam. Unfortunately, all too often a ban in one country simply shifts the deforestation to others or drives illegal logging. For example, the 1998 ban in China following the Yangtze flooding led to sharp increases in logging in Myanmar (formerly Burma) and Russia, much of it illegal. 22
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