Exploding great green whoppers

The myth that rainforests are vital to the earth is damaging policy-making and the search for scientific truth, says Philip Stott

Do we really need rainforests? For the Greens that is a rhetorical question. The juggernaut of the green myth of deforestation through human carelessness and greed was set rolling long ago.

Since the 1960s, this myth has been enhanced by the addition of a gamut of scientific and morality myths, all aiming to persuade us that the rainforest is vital for maintaining the stability and balance of the earth - indeed, for our very survival on this planet.

Are the forests not "the lungs of the earth", "the living sinks" that will help to buffer our human excesses of carbon dioxide emissions as we recklessly warm the atmosphere, the richest remaining "library" of genetic resources for us to use?

The false idea that forest is the normal clothing of the earth has many roots. Above all, it reflects the twin birth of the science of ecology and the religion of environmentalism, which sprang from late19th-century Romanticism in Germany, England and Massachusetts. "Nature endeavours to keep the Earth clothed with wood of some kind," wrote Henry David Thoreau.

This is, of course, nonsense. Even if we ignore the fact that vast oceans, dry grasslands and deserts dominate the continents, and have long done so, tropical savannahs occupy only around one-third of the land surface of the earth. Yet the tenets of ecologism were idiosyncratically derived from the very few parts of the world characterised by wooded domains.

This idea of the ancient forest came to be deeply imbued in European colonial officials, so much so that they instinctively assumed that any non-forested land must have been originally "forested" and later cleared by fire and man. We now know that most such areas have not carried a "forest" for millions of years.

At the end of the last Ice Age, only some 12,000 to 18,000 years ago, the tropics that are today occupied by these "ancient cathedrals" were seasonal savanna grasslands, both cooler and much drier than now. There were no rainforests in the Malay Peninsula and much of Amazonia, and, despite the increasing human development of forested space, there are still more rainforests now than there were then.

The whole farrago of scientific gobbledegook becomes painfully obvious in the myths of the rainforest as the lungs of the world. What do lungs do? They gulp in oxygen and give out carbon dioxide. If the rainforests are indeed the lungs of the world, they should surely be cut down as quickly as possible! If you truly want trees to take up carbon, you require newly planted, vigorous young plantations.

The myth is exposed. Rainforests are not at all essential for maintaining the ecological balance of the earth. We no more need trees than we did the forests of Europe, largely cleared by the 17th century.

Some people, especially in the rich countries of the North, may like rainforests, while others may psychologically need them as part of their own romantic New Age agenda. But these are different matters.

The innate danger of the rainforest myth is that it has grown into a myth. Moreover, it is founded on a series of little green lies, or "great green whoppers", as one of my academic colleagues calls them. These not only deny the fundamental search for truth in science, but, far more seriously, they warp policy-making with regard to the developing world.

Philip Stott is professor of biogeography, School of Oriental and African Studies, University of London. His monograph Tropical Rainforest is published this month by the Institute of Economic Affairs.

Do we need rainforests? Email us on soapbox@thes.co.uk