Over the past quarter-century huge areas of Amazonian forest have been reduced to ashes. The conquest of the Amazon resembles more a scorched earth policy than development. The rate of deforestation has been close to exponential, and it has all been for nothing.

The forests of the Amazon are home to at least two-thirds of the world’s organisms. They are known to nourish three million species, and recent research suggests that the number could actually be ten times higher. The destruction now going on will, if it continues, destroy or threaten more than half the world’s species of animals and plants over the next twentyfive years.

A holocaust of this type rivals the mass extinctions of dinosaurs and other species in the Cretaceous Period, which changed forever the world and the path of evolution. Many of the plants that will now vanish hold promises of food, medicine and fodder—building blocks in the biological economies of the future. Cures for cancer, skin diseases, aids, etc., may be reduced to ashes along with the trees.

In the end the loss of individual species and arcane plants may not cause medical science to collapse. But the incineration of millions upon millions of acres, and of the organisms that live there, is now coming home to everyone in the form of the ‘greenhouse effect’. Carbon dioxide from the burning forests traps solar radiation, thus causing the atmosphere to heat up to levels threatening to civilization. Indeed, some scientists say that within a few decades major climatic shifts will turn the North American grain belt into a permanent dust bowl, while the flooding of numerous Pacific islands and Asian coastlines will reduce the area of productive paddy land and probably strain food production capacity.

Susanna Hecht, who trained in biology, economics and soil science, first went to the Amazon Basin in 1975 and began her landmark study of what happens when forests are cut down and converted into rapidly degraded pasture. She has been working in the Amazon for several years, in southern Para and northern Mato Grosso, with the Kayapo Indians, peasant groups, and the rubber tappers in Acre whose leader, Chico Mendes, was recently assassinated. She is a professor at the Graduate School of Planning at ucla. The following interview took place shortly after the Oaxaca Conference.