A widespread drought in the Amazon rain forest last year was worse than the “once-in-a-century” dry spell in 2005 and may have a bigger impact on global warming than the United States does in a year, according to British and Brazilian scientists .
More frequent severe droughts like those in 2005 and 2010 risk turning the world’s largest rain forest from a sponge that absorbs carbon emissions into a source of the gases, accelerating global warming, the report found.
Trees and other vegetation in the world’s forests soak up heat-trapping carbon dioxide as they grow, helping cool the planet, but release it when they die and rot.
The study, published in the journal Science, found that last year’s drought caused rainfall shortages over a 1.16 million square-mile (3 million square km) expanse of the forest, compared with 734,000 square miles (1.9 million square km) in the 2005 drought.
GREATER WEATHER EXTREMES
The widespread drought last year dried up major rivers in the Amazon and isolated thousands of people who depend on boat transportation, shocking climate scientists who had billed the 2005 drought as a once-in-a-century event.
Under the more extreme scenarios, large parts of the forest could turn into a savannah-like ecosystem by the middle of the century with much lower levels of animal and plant biodiversity. Although human-caused deforestation in Brazil has fallen sharply in recent years, scientists say the forest is still vulnerable.
“You could quite rapidly move to a much drier Amazon with less forest there,” Lewis told Reuters.
The research was a collaboration among scientists at the University of Leeds and the University of Sheffield in Britain and Brazil’s Amazon Environmental Research Institute.