Shrinking forests

Posted: 7 May 2008

Forests worldwide cover some 3.9 billion hectares - almost a third of the earth's land surface excluding Antarctica and Greenland. Though vast, this wooded area is only half the size of forested land at the dawn of agriculture some 11,000 years ago.

Between 1990 to 2005, the world lost 3 per cent of its total forest area, an average decrease of some 0.2 per cent per year, according to FAO's State of the World's Forests 2007 report.

Net forest loss is 7.3 million hectares per year or 20,000 hectares per day, equivalent to an area twice the size of Paris.

But there is some good news in the report: a number of regions of the world are reversing centuries of deforestation and are now showing an increase in forest area. From 2000 to 2005, 57 countries reported an increase in forest area, and 83 reported a decrease.

Ten countries account for 80 per cent of the world's primary forests, of which Indonesia, Mexico, Papua New Guinea and Brazil saw the highest losses in primary forest in the five years running from 2000 to 2005. Most forests are no longer in their original condition, having changed in composition and quality. Tropical and sub-tropical forests comprise 56 per cent of the total amount of forested area, while temperate and boreal (northern) forests account for 44 per cent (the remaining 5 per cent is mainly managed plantations).

Primary forest with no visible signs of past or present human activity account for 36 per cent of the world's total forest area, but these primary forests are being lost or modified at a rate of six million hectares a year.

Forest cover

Global estimates of forest cover change are difficult to make because of conflicting definitions of what constitutes a forest, lack of satellite and radar data, and unmonitored land use change.

FAO has estimated that the world lost 94 million hectares of forest in the last decade of the twentieth century.(See data.) This assumed that developing countries lost 130 million hectares while the industrial world gained 36 million hectares as abandoned agricultural areas returned to forest.

The yearly loss of natural forests during this period, which includes deforestation plus the conversion of natural forests to tree plantations, was 8.9 million hectares - 94 per cent of which occurred in the tropics.

  • During the 1990s, Brazil suffered the heaviest loss of forest-23 million hectares. South America as a whole saw net losses of 37 million hectares. In Africa, 52 million hectares were destroyed. Sudan, Zambia, and the Democratic Republic of the Congo account for half of Africa's forest loss. While the United States gained 4 million hectares of forests, Mexico lost over 6 million, although government reports reveal the loss may be even higher. The total net losses for North and Central America were 6 million hectares.

  • A massive reforestation campaign in China meant the country added an average of 1.8 million hectares each year during this period, largely because bans on deforestation near the end of the decade heightened the country's reliance on plantations and imports of forest products from other nations. In Indonesia, where tree felling destroyed 13 million hectares over the decade, forest loss has accelerated and now averages 2 million hectares each year. Over the decade, forest cover in all of Asia declined by 4 million hectares.

  • Although FAO data suggest that world forest loss is slowing, deforestation in tropical areas is accelerating, exceeding 13 million hectares each year. As tree cutting in many parts of the world accelerates, nearly half of the remaining forests are at risk. The World Resources Institute estimates that about 40 per cent of the world's intact forests will be gone within 10-20 years, if not sooner, considering current deforestation rates.

  • Wood consumption drives deforestation. Since 1960, global industrial wood production has risen by 50 per cent, to 1.5 billion cubic metres, four fifths of which is from primary and secondary-growth forests. About the same quantity, 1.8 billion cubic metres, is burned directly as wood fuel each year in developing countries.

  • Worldwide, only some 290 million hectares of forested land are under protection from logging, but even protected areas are threatened by illegal exploitation. Of 200 areas of high biological diversity worldwide, illegal logging threatens 65 per cent. All told, illegal logging has devastated public forests around the globe, reducing incentives for locals to invest in sustainable forestry and accumulating losses of revenue to governments of some $15 billion annually.

  • Forest plantations now cover more than 187 million hectares, less than 5 per cent of total forested area, but account for 20 per cent of current world wood production. As natural forests are exhausted or come under protection, a growing share of future wood demand will be satisfied from tree farms.

  • Well-planned and managed plantations can efficiently satisfy timber demand. Unfortunately, the world has seen many plantations raised at the expense of old growth or other extremely diverse natural forests. In some cases, governments grant forest concessions to logging companies providing they plant replacement trees, but after the companies clearcut, they leave the land bare and move to new areas. In Indonesia, for example, 9 million hectares have been allocated for development as industrial timber plantations, but only 2 million hectares have been replanted.

  • A satellite-based survey of the world's forests by the UN Environment Programme, along with NASA and the U.S. Geological Survey, found that 80 per cent of largely intact forests (those with a canopy closure of over 40 per cent) are located in just 15 countries. A full 88 per cent of the key closed forest areas are sparsely populated, making them hopeful targets for conservation. Short of calling for a moratorium of all logging, conservation in these 15 countries offers a reasonable starting point for forest preservation.

This material is updated from a contribution by Janet Larsen, staff researcher with the Earth Policy Institute. A longer version of this can be found at the Institute's website address above. Copyright © 2002 Earth Policy Institute.

Related links:

Forest Trends Global Forest Watch FAO Forest Resources Assessment 2005

World Conservation Monitoring Centre

IUCN - World Conservation Union

WWF Forests for Life Programme