Australia looks set to ratify the Kyoto Protocol later this month after prime ministerial front-runner Kevin Rudd said he would sign immediately if elected.

Rudd, leader of the opposing Labor party, announced the plan this week alongside a $900m Clean Energy Plan to tackle Australia's growing environmental crisis.

His endorsement of Kyoto distances him further from prime minister John Howard, who has repeatedly refused to ratify the agreement, claiming it will slash jobs, hurt businesses and impact the economy.

"Acting now on climate change is not only good for the environment, but good for the Australian economy," argued Rudd, who is still leading the polls as the likely candidate to succeed Howard at the November 24th federal election.

Signing Australia up to Kyoto would also further isolate the US, which would become the last developed economy not to back the international agreement.

Rudd's environmental plan - targeted at cutting greenhouse gas emissions by 60 per cent before 2050 - includes a $500m Renewable Energy Fund, a $240m Clean Business Fund and a $150m Energy Innovation Fund.

The business fund aims to help Australian businesses develop alternative energy and water efficiency projects.

However, Howard estimates Labor's climate change policy will cost $130m over the next four years, alongside a further $300m for its Clean Coal Initiative.

Outlining his own environmental plans this week, he said: "We need to have a lower carbon future, but do it in a way that does not destroy jobs, weaken the coal industry and ensures that all nations of the world play their part in contributing to a reduction in greenhouse gas emissions."

Howard has also pledged to introduce a Clean Energy Target and an emissions trading scheme to help cut emissions.

The debate came as a new report by Washington's Center for Global Development showed Australian power plants are amongst the world's worst polluters, producing more carbon dioxide emissions per person than the US and almost five times that of China.