Global Biogeochem. Cycles 22, GB4007 (2008)

Credit: ISTOCKPHOTO.COM/BRASIL

Fires fanned by drought and deforestation could consume much of the Amazon rainforest over the twenty-first century, reports a new study. Numerous climate models project worsening dry seasons in the Amazon, but the impact on fire risk, and its interaction with deforestation, is less well-understood.

Nicola Golding and Richard Betts, of the Met Office Hadley Centre, UK, combined a global climate model with a fire danger index to simulate changes in fire risk in the Amazon until 2090. According to the model, an area of high fire risk could spread along southeast Amazonia as early as the 2020s; by the 2080s, at least 50 per cent of the forest — up to 93 per cent in some model runs — lies in the danger zone. Compounding the threat, growing areas of fire risk in eastern Amazonia are likely to overlap with expanding areas of slash-and-burn forest clearing, raising the chances that intentional fires will spread.

The researchers warn that if the regional climate changes simulated for Amazonia hold true and deforestation continues, the entire eastern portion of the rainforest could be at risk by 2080. The loss of forest cover might further intensify regional droughts, they note, and would remove one of the planet's sizeable carbon sinks.