“The world has changed in the last hours.”

These words were texted to me from Nusa Dua on Saturday evening by Bill Hare, Greenpeace International’s climate policy director and arguably the world’s most influential environmentalist.

The sentiment was inspired by the dramatic capitulation of the United States at the final plenary session of the Bali Conference of the Parties in the vast auditorium of the conference centre at the Westin Hotel.

The standing-room-only session was unprecedented in the history of climate change negotiations. The pressure on the US delegation was immense and, in the end, unbearable.

When the head of the US delegation Paula Dobriansky had declared that the United States was unwilling to support the draft that had been agreed by all other parties, she was booed and jeered, an unheard of outburst.

But when a world power demands that poor countries commit to stronger measures to cut their emissions when it has itself refused to do anything about its own, it was a surprise that they were not set upon by the hundreds who packed the room.

The US position has been built on the arrogance, obstinacy and disregard for the facts characteristic of neo-conservatives. The Bali meeting exposed yet again the damage to US prestige of President Bush’s foreign policy.

The big countries threatened to boycott the planned January meeting of Bush’s major emitters group, seen by most as a third-order process but a credibility life-line for the US President.

In the last hours in Bali UN Secretary-General Ban Ki-moon, President of the Convention Susilo Bambang Yudhoyono and UNFCCC Executive Secretary Yvo de Boer made impassioned interventions to pressure the US delegation to yield.

As one nation after another rose to condemn the United States, it fell to the delegate from humble PNG to encapsulate the mood of the world: “If you are not willing to lead then get out of the way” he said to acclamation.

In the end it was too much; even Bush’s hard-arsed negotiators proved human and the super-power was humiliated in the most public way.

Thank God Australia no longer must share the opprobrium that rained on the United States.

Australia’s defection to the cause of climate progress was instrumental in the Bali outcome because it left the United States friendless. Kevin Rudd played a clever and constructive hand, and Penny Wong made a deep impression on negotiators from around the world for her deft negotiating skills and extraordinary ability to get on top of the dauntingly complex issues in record time.

The Bali roadmap commits both developed and developing countries to negotiate towards a treaty embodying “nationally appropriate mitigation actions”. As South Africa pointed out, such a commitment from developing countries would have been unthinkable a year ago.

The shift reflects rising alarm about the impacts of global warming and the long process of trust-building, led by the Europeans, that convinced China, India, Brazil and other developing countries that the rich world, with the exception of the United States, is serious about deep cuts in their carbon emissions.

Two sets of negotiations occurred simultaneously in Bali—the “Convention track” in which the US participated and caved in, and the “Kyoto track” from which the US, as a non-ratifier, was excluded. The declaration coming from the latter in the end included reference to the science-based emission cuts of 25-40% on 1990 levels by 2020 for developed countries.

Australia agreed to this, a decision undoubtedly made easier by the statement of support for the target range by Opposition climate change spokesman Greg Hunt, which removed a huge chunk of potential domestic criticism.

Support for the 25-40% goal presents Kevin Rudd with the task of setting a 2020 target that will not be seen to undermine the aspirations of the post-Kyoto treaty expected to be agreed in Copenhagen in December 2009.

The Bali roadmap will almost certainly give rise to a post-2012 treaty that builds on and strengthens the Kyoto Protocol, as was always intended.

It will have mandatory emission reduction targets for rich countries, some form of abatement commitment from developing countries, an international emissions trading system, a Clean Development Mechanism, along with technology transfer and financial assistance for poor countries.

There are no surprises. It’s Kyoto plus. No one underestimates the magnitude of the task ahead. Climate change policy has always lagged well behind the science. The agreement in Bali provides a desperately needed accelerator to policy.

And it sends an unambiguous message to the business world. Watch the stampede and, if money is your thing, buy shares in renewable energy and carbon offset companies today.

Clive Hamilton is the author of Scorcher: The dirty politics of climate change (Black Inc. 2007).