MercoPress. South Atlantic News Agency

Warn Against Amazon Destruction.

The millions of tons of greenhouse gases spewed into the atmosphere every year by burning in the Amazon are almost entirely absorbed by the rain forest, scientists said.

But as trees continue to be cut down at an ever faster pace, the jungle will no longer be able to absorb the gases, blamed in part for fueling global warming, scientists warned at the Large Scale Biosphere-Atmosphere Experiment in Amazonia.

"We have to reduce the incidence of burning to allow the rain forest to clean (the air) more efficiently," Paulo Artaxo, a University of Sao Paulo professor and the conference coordinator, said.

Farmers burning jungle scrub for pasture and planting contributed some 200 to 300 million tons of carbon dioxide to the atmosphere last year, an increase of about 30 percent over the previous year, Artaxo said. Since the forest absorbs the same amount of carbon every year, the effect on global warming was essentially zero.

Yet the Amazon is disappearing rapidly ? 9,169 square miles of rain forest were cut down last year alone.

As the forest shrinks, it also leads to more carbon dioxide because farmers in the Amazon routinely set fires to burn off the fast-growing jungle brush and replenish the soil.

In the near future, scientists say, the Amazon rain forest will go from being the world's largest absorber of greenhouse gases to a net contributor to global warming.

The results from the Large Scale Biosphere-Atmosphere Experiment in Amazonia are being presented at a conference that runs through Thursday.

The experiment, which began in 1998 and is expected to continue through 2006, studies the interaction between the Amazon rain forest, the world's largest remaining tropical wilderness, and regional and global weather patterns.

It involves more than 1,000 scientists and specialists from over 100 research institutions including NASA, and is being called the largest international environment research project ever.

Enter Amazonia

Amazonia is the world's largest tropical rainforest, spanning more than half of Brazil. Within the 2.5 million square miles of the Amazon Basin resides a wealth of life richer than anyplace else on earth, including 500 mammals, 175 different lizards, 300 other reptile species, tree climbers of every kind, and a third of the world's birds. Millions of species that remains undiscovered. How did this natural bounty come to be?

To understand the origins of Amazonia, one needs to travel back in time some 15 million years to the formation of the Andes mountains. Until that time, the Amazon river flowed west, emptying into the Pacific Ocean. But when South America collided with another tectonic plate, the Andes formed, blocking the Amazon at its Pacific end. Inland seas, now cut off from the ocean, transformed into freshwater lakes, and the environment of the Amazon basin changed radically. The Amazon's flow gradually reversed, now flowing from west to east, until roughly 10 million years ago, the river reached the Atlantic.

The Amazon River is the lifeline of Amazonia, carrying an astounding 16 percent of all the river water in the world over its 6,500 miles. A fifth of all river water discharged into the world's oceans is conveyed through the Amazon, 10 times that of the Mississippi River.