The most detailed investigation of the fate of the world's greatest tropical rainforest estimates that as little as 5per cent of the Amazon may remain in its pristine, wild state by 2020.
This pessimistic scenario is painted by a team of Brazilian and American scientists who have analysed how the delicate Amazon ecosystem will respond to a new $40bn road development project.
Although the Amazon now accounts for about 40 per cent of the Earth's rainforest, the scientists believe that within 20 years this will have dwindled alarmingly as a direct result of an ambitious scheme, known as Avanca Brasil, to "Advance Brazil" by building roads, railways and hydroelectric dams.
The scientists accuse the Brazilian government of fast-tracking the project by keeping out environmental agencies including its own Environment Ministry thus accelerating logging and deforestation.
"Once a road or highway is built, a Pandora's box is opened which is almost impossible for a government to control," said William Laurance, of the Smithsonian Tropical Research Institute in Panama, who led the study. "Once you build a road into a pristine forest you start an inevitable process of illegal colonisation, logging, land-clearing and forest destruction."
Using satellite pictures, the team developed computer models to predict the course of forest destruction based on what has happened to the Amazon over the past 20 years of road building and development.
"We used the past as a guide to the future. We looked at the entire network of roads and highways in the Amazon to see how deforestation occurs in the region of a new road," said Dr Laurance. "There's really nothing that has been done that approaches the scale of what we've done. Our computer model is very comprehensive."
The study, published today in the journal Science, shows two possible scenarios: "optimistic" and "non-optimistic" futures. Both suggest that the Amazon will be drastically altered by current development schemes. Under the less optimistic scenario, more than 95 per cent of the Amazon will lose its untouched status and 42 per cent of the forest will be totally denuded or heavily degraded by 2020. Even under the more optimistic view, well over half of Amazonia will no longer be in a pristine state and about 30 per cent will be lost forever.
The Amazon is already experiencing the most rapacious destruction seen in any rainforest in the world, with the loss of almost 5 million acres a year. However, the Avanca Brasil plan will increase this rate of loss by between 14 per cent and 25 per cent each year, according to the study. "At stake is the fate of the greatest tropical rainforest on Earth," the scientists say.
Dr Laurance said that road building is by far the most potentially destructive aspect of the development programme because of the way it fragments the rainforest into smaller and increasingly unviable segments. "To eat a pie efficiently you chop it into smaller pieces, which is what these development projects have been doing to the Amazon," he said.
Several international and domestic attempts are under way to preserve the Amazon, including a $340m grant from the G7 nations, but these efforts "pale in comparison to the scale of the ongoing and planned development activities" currently funded to the tune of $40bn from 2000 to 2007, the scientists say.
© 2001 Independent Digital (UK) Ltd.