[RIO DE JANEIRO] Unless Brazil enforces existing conservation laws and takes steps to prevent deforestation on private land, it will lose more then 40 per cent of its Amazon rainforest by 2050, say scientists.
The predictions, published today (24 March) in Nature, are among the first to emerge from a unique, large-scale study that is using computer models to simulate how factors such as logging, farming, climate and policy decisions could affect the future of the forest.
The models predict that unless Brazil takes action, eight of the Amazon basin's twelve main watersheds will lose more than half of their forest, increasing the risk of flooding.
They also suggest that almost 100 of the region's wild mammal species could lose more than half of their habitat.
The news is not all bad, however, says lead author Britaldo Soares-Filho of the Federal University of Minas Gerais State, Brazil.
The study predicts that if Brazil puts in place measures to protect the Amazon, as much as 73 per cent of it could remain intact in 2050.
To achieve this, Brazil would need to enforce existing laws and prevent the loss of rainforest on private land by creating economic incentives for farmers to manage their land sustainably.
As well as protecting watersheds and conserving biodiversity, this would prevent 17 billion tonnes of carbon being released into the atmosphere by 2050, say the researchers.
Under the model's optimistic scenario, the Amazon would still have 4.5 million square kilometres of living forest in 2050, Soares-Filho told SciDev.Net. Currently, the Brazilian Amazon covers 5.3 million square kilometres.
Brazil is making increasing efforts to control deforestation, and to set up more than 70,000 square kilometres of new conservation areas that were designated in 2004 and 2005.
But, says Soares-Filho, this is not enough as most areas at risk are on private land that could be profitably deforested for timber or to farm cattle or soybeans.
The researchers say that ways of encouraging farmers to manage their forested land sustainably could include certification schemes that reward environmentally sound timber production, or a carbon trading scheme to reward avoided greenhouse gas emissions.
Reference: Nature 440, 520 (2006)