In normal years, the Amazon Biome as a whole, including the Guiana Shield forests, absorb 1.5 billion tonnes of carbon dioxide a year (Phillips et al, 2009). A severe drought in 2005, affecting the South West of the Amazon, was estimated to have released 5 billion tonnes of carbon dioxide as a result of tree mortality and forest fires. As a comparison, the United States emitted 5.4 billion tonnes of carbon dioxide as a result of fossil fuel use in 2009. The 2005 drought was described as a ‘one in a 100 year event’. Just five years later, in 2010, the Amazon experienced an even more severe drought, affecting a significantly larger area compared to the 2005 drought. It is estimated that 9 billion tonnes of carbon dioxide were released during this latest drought (Lewis et al, 2011).
Increased temperatures and decreased precipitation caused by global warming are exacerbating the effects of deforestation and forest degradation, which could lead to a tipping point where the tropical moist forest ecosystem collapses and is replaced over large areas by scrub and savanna. Some climate models predict that such a tipping point could occur as early as 2030, destroying up to 55% of the Amazon rainforest (Nepstad, 2008).
A recent study by the International Development Bank states that global warming may cost the Amazon biome region up to $100bn by the year 2050 due to declines in agricultural yields, the disappearance of glaciers, floods, droughts, and other associated problems (IBD, 2012).
This page is part of our series of articles on the Amazon System, emerging out of the experience of Dr Andrea Berardi, a Lecturer in Environmental Information Systems at The Open University to support the BBC Two series I Bought a Rainforest. See the full reference list for these articles.
Dr Berardi is a co-investigator on Project COBRA. COBRA is researching ways to integrate community solutions within policies addressing escalating social, economic and environmental crises, through accessible information and communication technologies.