New Prime Minister Kevin Rudd signed the paperwork Monday to ratify the Kyoto Protocol, making good on an election promise to overturn Australia's decade-long opposition to the international global warming pact.
"This is the first official act of the new Australian Government, demonstrating my government's commitment to tackling climate change," Rudd said in a statement issued hours after he was officially sworn in Monday.
The dramatic step just nine days after Rudd was elected looked likely to send Australia's standing soaring at international climate change talks that started Monday in Indonesia, and to intensify pressure on Washington to join the Kyoto framework.
Rudd said he had signed the "instrument of ratification" of the Kyoto Protocol. The document would now be sent to the United Nations, and ratification would come into force 90 days after it was received, Rudd said, predicting Australia would become a full member of the Kyoto Protocol before the end of March 2008.
"Australia's official declaration today that we will become a member of the Kyoto Protocol is a significant step forward in our country's efforts to fight climate change domestically - and with the international community," he said.
Rudd, 50, a Chinese-speaking former diplomat, led the left-leaning Labor Party to a sweeping victory at Nov. 24 elections that ended more than 11 years of conservative rule under former Prime Minister John Howard.
Howard had steadfastly refused to ratify Kyoto, arguing that Australia would not agree to a pact setting greenhouse gas emission targets unless big polluters among developing countries such as China and India were also subject to binding targets.
Rudd said Australia wanted to help fix the problem of global warming.
"To be part of the climate change solution we've got to be part and parcel of the negotiating process ... and you can't do that properly until you've ratified Kyoto," Rudd told a television interviewer on Monday before attending the swearing-in ceremony.
But he said striking a new international agreement on the problem was not going to be easy.
"It'll take a lot of time, a lot of horse trading, a lot of negotiation, it's going to be a tough process," he said on Nine Network television.
Australia's overall contributions to global greenhouse gas emissions are small, but it is one of the largest polluters per capita and its stance on Kyoto is powerfully symbolic.
Ratifying Kyoto will leave the United States isolated among wealthy countries in shunning the agreement.
In a sign of the significance of Australia's policy shift, delegates and scientists at the world's largest climate change conference, being held in Bali, Indonesia, erupted in applause Monday when Australia's delegate, Howard Bamsey, told the plenary that Canberra was coming on board the Kyoto process.
Rudd was the first of 30 ministers to take the oath of office before Governor General Michael Jeffery on Monday, formalizing the handover of government.
Among his Cabinet are Australia's first female deputy prime minister, Julia Gillard, who as acting prime minister will become the first woman to formally take charge of the country when Rudd goes to Indonesia.
Also in the Cabinet are ex-rock star Peter Garrett and Australia's first Asian-born woman in Parliament, Penny Wong, who share responsibilities for Australia's environment and climate change.
Both ministers will accompany Rudd to Bali.
Rudd conceded Monday that fighting climate change would have its costs. He said figures indicated Australia would exceed the emission targets spelled out in the Kyoto pact by about 1 percent, and would likely face penalties as a result.
And he warned that food and energy prices could be expected to rise because of measures implemented to deal with climate change.
"We've just got to be realistic about this," Rudd told Australian Broadcasting Corp. radio.
He renewed his government's goals of reducing greenhouse gas emissions by 60 percent by 2050, switching Australia's coal-dominated power generation industry to 20 percent renewable energy by 2020, and creating a national emissions trading scheme by 2010.