Amazon jungle becoming savanna?
June 12, 2008 · Updated 1:09 PM
RIO DE JANEIRO, Brazil (AP) Global warming could spell the end of the worlds largest tropical rain forest, transforming the Amazon into a grassy savanna before the end of the century, researchers say.
Jose Antonio Marengo, a meteorologist with Brazils National Space Research Institute, said that global warming, if left unchecked, will reduce rainfall and raise temperatures substantially in the ecologically rich region.
We are working with two scenarios: a worst case and a second, more optimistic one, he said in a telephone interview.
The worst case scenario sees temperatures rise by five to eight degrees (Celsius) until 2100, while rainfall will decrease between 15 and 20 per cent. This setting will transform the Amazon rain forest into a savanna-like landscape, Marengo said.
That scenario supposes no major steps are taken toward halting global warming and that deforestation continues at its current rate, Marengo said.
The more optimistic scenario supposes governments take more aggressive actions to halt global warming. It would still have temperatures rising in the Amazon region by three to five degrees Celsius and rainfall dropping by five to 15 per cent, Marengo said.
If pollution is controlled and deforestation reduced, the temperature would rise by about five degrees Celsius in 2100, said Marengo.
Within this scenario, the rain forest will not come to the point of total collapse.
Marengos findings were part an 800,000 real (US$373,000) study that began two years ago and that will continue until 2010. The study, financed by the World Bank and the British government, seeks to project climatic changes over the next 100 years.
Sprawling over 4.1 million square kilometres, the Amazon covers nearly 60 per cent of Brazil. Largely unexplored, it contains one-fifth of the worlds fresh water and about 30 per cent of the worlds plant and animal species many still undiscovered.
Marengo is optimistic that the worst-case scenario can be averted, but he said that would require a major effort by industrialized countries. He said Brazil should do its part by reducing deforestation and burning in the Amazon region.
About 20 per cent of the rain forest has already been cut down and while the rate of destruction has slowed in recent years, environmentalists say it remains alarmingly high.