Super-road spells death for Amazon forest
By Steve Connor
The most detailed investigation of the fate of the world's greatest tropical rainforest estimates that as little as five percent 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 $40-billion (R312-billion) road development project.
Although the Amazon now accounts for about 40 percent 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.
William Laurance, of the Smithsonian tropical research institute in Panama, who led the study, said: "Once a road or highway is built, a Pandora's box is opened which is almost impossible for a government to control.
"Once you build a road into a pristine forest you start an inevitable process of illegal colonisation, logging, land-clearing and forest destruction."
The team, which included scientists from Brazil's National Institute for Amazonian Research, developed computer models to predict the course of forest destruction based on what has happened to the Amazon during 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 occurred in the region of a new road," said 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 on Friday in the journal, Science, shows two possible scenarios: "optimistic" and "non-optimistic" futures. Both suggest that the Amazon will be drastically altered by development schemes.
Under the less optimistic scenario, more than 95 percent of the Amazon will lose its untouched status and 42 percent 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 percent will be lost forever.
The Amazon is already experiencing the most rapacious destruction seen in any rainforest in the world, with the loss of about two million hectares a year.
However, the Avanca Brasil plan will increase this rate of loss by between 14 percent and 25 percent each year, according to the study.
"At stake is the fate of the greatest tropical rainforest on Earth," say the scientists.
Deforestation so far has largely occurrred on the southern and eastern fringes of the Amazon, but the building of roads will allow logging deep within the rainforest.
Laurance said the road-building was by far the most potentially destructive aspect of the development programme because of the way it fragmented 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 $340-million grant from the G-7 nations, but these efforts "pale in comparison to the scale of the present and planned development activities" - funded to the tune of $40-billion from 2000 to 2007, say the scientists.
"The Amazonian road network is being greatly expanded and upgraded with many unpaved sections being converted to paved, all-weather highways," say the scientists.
"The effects of these massive projects and other development trends on Amazonian forests have not been assessed systematically. Our models suggest that, under status-quo conditions, efforts to promote conservation planning in the Brazilian Amazon will be overwhelmed by prevailing destructive trends.
"Although a combination of threatening factors is responsible, special attention should be focused on Avanca Brasil, because it is a massive new initiative that will open vast areas of the Amazonian frontier to development activities.
"Avanca Brasil typifies the top-down planning process in the Amazon, in which mega-projects are proposed and approved long before the environmental cost and risks can be evaluated," they say.
The study's computer models - partly funded by the US National Aeronautics and Space Administration (Nasa) - were made using satellite pictures of rainforest.
"We're trying to map out the implications. We feel it hasn't been looked at yet," he said. "When you view these forests from a distance, they look OK, but when you stand in them, you can see they've been thinned, and that they've changed.
"It's like they have holes punched in them. These holes can make a rainforest dry out and be vulnerable to fire."
Carlos Peres, a Brazilian conservation scientist based at East Anglia University in Norwich, said fires were among the worst side-effects of building new roads in the rainforest.
"Everywhere you get a new road, paved or not, it has increased logging and, wherever you get logging, you increase the risk of fires -far more severe fires that burn the forest canopy.
"In two to three decades, there could be a change from a closed-canopy forest to a scrub, savannah-like landscape," he said.
"If the trends continue, you're going to see a higher increase in the pace of forest conversion and we'll end up with a very fragmented landscape."
The scientists suggest that Brazil should accept "carbon-offset funds" paid by the developed world to save rainforest. Brazil has rejected this, a decision which the scientists call "an appalling mistake".
Dr Peres, who was born in the Amazon, is pessimistic about the Avanca Brasil scheme, but admits many fellow Brazilians would disagree.
"To others, development is a sign of a prosperous future. I'd rather slow down the pace of change, but that's not what a lot of my fellow citizens want."