A compromise deal for a new international climate change agenda was agreed at the UN summit in Bali today.
The move was hailed by environment secretary, Hilary Benn, as "an historic breakthrough".
Ministers from around 180 countries were united in accepting the agenda for a global emissions cuts agreement to launch negotiations for a post-2012 agreement to tackle climate change.
Consensus for the road map followed a dramatic U-turn by the US, which had threatened to block the deal at the 11th hour and been booed by other countries.
It dropped its opposition to poorer countries' calls for technological and financial help to combat the issue.
Applause
The sudden reversal by the US in the marathon talks which saw the country duelling with European envoys was met with rousing applause.
While it will be two years before a final deal on post-2012 is likely to be struck, countries have been fighting for the kinds of things they want to see on the table for those talks.
Mr Benn said: "This is an historic breakthrough and a huge step forward.
"For the first time ever all the world's nations have agreed to negotiate on a deal to tackle dangerous climate change."
He said it was the compelling clarity of the science and the strength of the case for urgent action that has made this agreement possible.
But it was political leadership that made it happen, Mr Benn added.
He continued: "Our changing climate has changed our politics, because we knew that we could not let people down.
"We came here saying we wanted a road map that included every country and covered emission reductions from developed countries and fair and equitable contributions from developing countries.
"We leave here with all of this and more - a groundbreaking agreement on deforestation, and others on adaptation and technology.
"And against predictions these negotiations will be guided by ambitious goals for emission reductions.
"What we have achieved here has never been done before.
"Less than a year ago, many would have said this agreement was impossible.
"Now we must make it work, and in the next two years agree the detail of a comprehensive global climate deal that will take us beyond 2012."
The agreement follows two weeks of insults, arguments and threatened boycotts and trade sanctions, as countries wrangled over who should take responsibility for cutting carbon pollution
UN secretary general Ban Ki-Moon, who returned to Bali as the conference stretched into another day, had earlier said he was "disappointed" at the lack of progress.
A highly emotional Mr Ban had told delegates: "Now the hour is late. It's time to make a decision.
"You have in your hands the ability to deliver to the people of the world a successful outcome to this conference."
Ministers worked through the night to hammer out the details of an agenda for the agreement, which will replace the current Kyoto Protocol.
The EU conceded on one of the main sticking points - the inclusion in the road map of a reference of 25% to 40% emissions cuts by developed countries by 2020, which scientists have said are necessary to avoid dangerous climate change.
The EU had insisted the figures were in the document because they are based on the science of the Intergovernmental Panel on Climate Change (IPCC) and an ambitious road map was needed.
But the US demanded - and won - their removal, claiming they could "prejudge" outcomes of negotiations over the past two years.
This morning the Europeans accepted a road map in which the targets were missing, as were references to the need for emissions to peak within 10 to 15 years and for global greenhouse gas output to halve by 2050.
Instead the document said countries recognise that "deep cuts in global emissions" will be required, and calls for a "long-term global goal for emissions reductions".
In turn the US conceded over the issue in the road map of how much developing countries need to do to curb their emissions.
Paula Dobriansky, the head of the US delegation, said: "I think we have come a long way here.
"In this, the United States is very committed to this effort and just wants to really ensure we all act together.
"We will go forward and join consensus."
Campaigning groups said the deal had been stripped of important targets and hit out at the US's "wrecking policy".
Keith Allott, Head of Climate Change at WWF UK, said:
"We are not at all pleased.
"We were looking for a road map with a destination."
But he praised the talks having been brought back from the brink of collapse, with the alliance of the G77 developing countries with the EU.
He said positive aspects included the beginning of a framework to ramp up the finance to help poorer countries adapt and potential for "real movement" with technology transfer.
Looking ahead, Mr Allott hoped for a new administration in the US.
"We are seeing a dynamic situation in many of the countries," he said.
"We have had a sea change in Australia."
Greenpeace said that the agreement had been stripped of the emission reduction targets that humanity needs.
"The Bush administration has unscrupulously taken a monkey wrench to the level of action on climate change that the science demands," said Gerd Leipold, executive director of Greenpeace International.
"They've relegated the science to a footnote."
Greenpeace said it remains confident that mounting public pressure on every continent will force governments over the next two years to agree "inevitable" deep cuts in greenhouse gas emissions.
The group criticised the US's strategy, saying the Bush administration was "shamed" by the firm resolve of the developing countries China, India, Brazil and South Africa, who came to Bali with concrete proposals.
Nelson Muffuh, a Christian Aid senior climate change policy analyst, said: "For most of the conference, the US delegation in particular proved a major obstacle to progress.
"They appeared to operate a wrecking policy, as though determined to derail the whole process.
"We welcome their last minute agreement to support the consensus in accepting the Bali road map, having said less than an hour earlier that it was unacceptable, and we sincerely hope they are serious in their stated desire to negotiate.
"But the way ahead will be hard. The Bush administration has said throughout that it wants to see developing countries agree to cuts in carbon emissions.
"A number of emerging economies put creative, flexible plans on the table, but will have little incentive to negotiate further until the industrialised world agrees deeper cuts.
"Climate change is already having a devastating impact on the lives of some of the world's poorest communities through drought and flooding."
He said the lack of clear targets in the road map leaves them exposed to further catastrophe.
"We were expecting a road map, and we've got one," said Mr Muffuh. "But it lacks signposts and there is no agreed destination."
A spokesman for the Carbon Markets Association (CMA) welcomed the breakthrough "of a road map to engaging all nations, including the US, in meaningful negotiations toward long-term commitments by 2009.
"The process to 2009 should at a minimum deliver an extension of the first phase binding commitments beyond 2012 as well the engagement of a broader group of nations with binding commitments."
The US is the only major industrial nation to reject Kyoto.
President George Bush has complained that it would unduly damage the US economy, and emission caps should have been imposed on China, India and other fast-growing developing countries.
The Bush administration favours a voluntary approach with each country deciding how it can contribute in place of internationally negotiated and legally binding commitments.