Paris: Environmental campaigners and governments pressed industrial nations, specifically the United States, to significantly cut their emissions of greenhouse gases, in response to yesterday's report on global warming.

South Africa's Environmental Affairs Minister Marthinus van Schalkwyk said failure to act would be "indefensible". His Indonesian counterpart said "drastic steps" were needed to slow rising temperatures.

"We are now beyond a critical turning point in the debate: those who continue to ignore the threat and its causes, or invoke half-baked arguments to confuse and obstruct, will be doing the greatest disservice imaginable to current and future generations," van Schalkwyk said in a statement.

The long-awaited report from the Intergovernmental Panel on Climate Change said global warming is "unequivocal", "very likely" man-made and will "continue for centuries" - findings bleaker than its last report in 2001.

"If the last IPCC report was a wake up call, this one is a screaming siren," said Stephanie Tunmore, of Greenpeace.

"The good news is our understanding of the climate system and our impact on it has improved immensely. The bad news is that the more we know, the more precarious the future looks," Tunmore said in a statement. "There's a clear message to governments here, and the window for action is narrowing fast."

The Indonesian minister, Rachmat Witoelar, has predicted that some 2,000 of Indonesia's estimated 18,000 islands would be swallowed by the sea within three decades because of man-made climate change.

"Developing countries must make binding commitments to cut emissions by 40 to 60 per cent. And we in Indonesia must guard against the burning of our forests and better monitor our industries," he said in the capital, Jakarta, where days of torrential rain caused rivers to break their banks yesterday, submerging streets in muddy water and inundating huge areas.