Indonesia has for the first time surpassed Brazil in clearing tropical forests, and losses are accelerating despite a 2011 moratorium meant to protect wildlife and combat climate change, scientists say.
Indonesia's losses of virgin forests totalled 60,000 square kilometres - an area almost as big as Ireland - from 2000-12, partly to make way for palm-oil plantations and other farms, a study said. And the pace of losses has increased.
"By 2012, annual primary forest loss in Indonesia was estimated to be higher than in Brazil," where clearance of the Amazon basin has usually accounted for the biggest losses, the scientists wrote on Sunday in the journal Nature Climate Change.
Deforestation in Indonesia in 2012 alone was 8,400 square kilometres versus 4,600 square kilometres in Brazil, it said.
"We need to increase the law enforcement, the control in the area itself," said Belinda Margono, lead author of the study at the University of Maryland, and who also works as an official at the Indonesian forestry ministry.
"The rain forests are the lungs of the planet. You have lungs to breathe and if you get rid of the lungs, the planet's going to suffer," said Matthew Hansen, a co-author of the report at the University of Maryland.
Indonesia imposed a moratorium on forest clearance in 2011, partly to slow losses that are ruining habitats of orang-utans, Sumatran tigers and other wildlife. Norway has also promised US$1 billion to Jakarta if it slows forest losses.
"It seems that the moratorium has not had its intended effect," the scientists wrote.
Trees absorb carbon dioxide, the main greenhouse gas blamed for causing global warming, as they grow and release it when they are burnt or rot. By UN estimates, deforestation may account for 17 per cent of all man-made greenhouse gases.
Sunday's findings focus only on the most important virgin forests, and exclude plantations, which can regrow quickly.