BY NOW just about everyone knows the world's tropical rain forests are rapidly disappearing. But alarming new evidence indicates the rate of depletion is even worse than anybody thought.
Some 50 million acres of forest, an area the size of Washington State, is now vanishing every year as the trees are cut for timber or burned to make way for farming or development.
The rate of loss is nearly 50 percent greater than estimated only 10 years ago. If this ravaging of the environment continues, all the tropical forests will be gone in 30 to 40 years.
The latest study, based on satellite surveys, was made by the World Resources Institute, an international research group, in collaboration with the United Nations. The researchers said the actual loss of forest is probably even greater than in their estimates.
Deforestation is recognized as one of the world's major environmental problems. Trees absorb carbon dioxide, and the loss of much of the world's forest cover has resulted in a rise in the amount of carbon dioxide in the atmosphere, enhancing the "greenhouse effect."
Trees also hold the soil, and wholesale clearing is a culprit in eroding the world's topsoil.
Another problem is loss of species. Forests are the habitat for an amazingly large and diverse population of plants and animals. As the forests are cut down, many species die out -- often even before they are discovered and analyzed for possible use to mankind.
Deforestation isn't just a problem of the tropics. The great temperate forests of America and Europe were largely destroyed long ago. Even now, the process is continues. The thousand-year-old forests of the Pacific Northwest are now almost gone, and their destruction will be complete in one more generation if we continue logging at the current rate.
That tragic prospect puts the current controversy in the Northwest over the rare northern spotted owl in proper perspective.
Lumber interests stress the millions of dollars' worth of timber and the thousands of jobs that will be lost to save a couple of thousand rare owls. The larger question is whether we should preserve at least some of the forest giants that began growing on this continent before Columbus arrived.
Eventually, we will have to shift logging operations from the virgin forests to second-growth forests now being grown for timber. Why not make the shift before our last great forests -- and all the rare ecology that goes with them -- are gone?
New studies reveal that logging, as done in the past, has been even more destructive than necessary. Instead of "clear-cutting" an entire area, foresters now propose partial cutting in order to preserve part of the forest and its ecosystem. The shift should be made as soon as possible.
The United States must work internationally on environmental problems.
But we will speak with more authority on saving the tropical forests if we have demonstrated the ability to save the remnants of our own once-vast forest lands.