US President George W. Bush. Photo / Reuters

US President George W. Bush. Photo / Reuters

American negotiators at the Bali climate conference came under mounting pressure yesterday to back mandatory caps on greenhouse gases, after Australia threw its support behind deep emission cuts and anti-global warming legislation passed a crucial test in the United States Senate.

The US, the world's largest producer of gases blamed for rising global temperatures, has resisted calls for strict limits on emissions at the United Nations conference.

The event is aimed at launching negotiations for a world climate agreement to follow the Kyoto Protocol when it expires in 2012.

Australia, which had stood with the US as the only major industrialised country to reject the Kyoto pact, reversed its stance this week and signed.

The Australian delegation confirmed yesterday that Canberra also supported cutting greenhouse gas emissions by between 25 per cent and 40 per cent below 1990 levels by 2020.

The Bush Administration's global warming stance suffered another blow when the Senate Environment and Public Works Committee passed a bill calling for the US to cut gas emissions by 70 per cent by 2050 from electric power plants, manufacturing and transportation.

The bill now goes to the full Senate.

The twin moves cheered environmentalists and others in Bali clamouring for dramatic action to stop global warming.

"This is a very welcome development," said Alden Meyer, of the Union of Concerned Scientists, in response to the Senate measure. "It shows the increasing isolation of the Bush Administration in terms of US policy on this issue."

David Waskow, of Oxfam, which provides food and other humanitarian aidfor the hungry, said the Senate legislation was a positive signal to developingnations and others in Bali who werelooking for America to take a more active role in battling climate change.

"It's one of the things that point the way to having the United States re-engage in the negotiations, and really I think in many ways demonstrates the US leadership on these issues. The Administration may not be there, but it's increasingly clear that the United States is, as a country."

Further momentum for serious greenhouse gas cuts, which experts say are needed to stave off the most destructive effects of rising temperatures, came from a petition released yesterday by a group of at least 215 climate scientists who urged the world to reduce emissions by half by 2050.