Ministers and officials from nearly 200 countries pulled off one of modern history's major repair jobs yesterday when they revived the global project to counter global warming, which had seemed critically damaged by the failure of the Copenhagen climate conference a year ago.
At a successor conference in Cancun, Mexico, they agreed a package of measures which are not yet enough to save the climate, but are enough to save the 20-year-old international climate change negotiating process from collapse – a real danger if the talks had ended in deadlock once again, as many observers expected.
After a fortnight's negotiations in the Mexican "super-resort" on the Caribbean coast, in which prospects of success often seemed bleak, the 15,000 delegates bridged their differences in the early hours of yesterday with a comprehensive deal, which was announced to thunderous applause and cheering.
They signed off a new framework in which all countries – and not just the rich nations, as previously – now have official, UN-recognised goals to cut their emissions of the greenhouse gases that are causing the atmosphere to warm (with this year likely to prove the warmest in the 150-year-old instrumental record).
They recognised that industrialised nations need to do more to cut emissions, officially adopted the target of keeping warming to 2C above pre-industrial levels, agreed that world emissions must soon peak, and agreed to a new international regime of monitoring of every country's emission-cutting efforts, which was previously anathema to China – now the world's biggest CO2 emitter.
Furthermore, in two radical new initiatives, they set up a huge, multi-billion-dollar Green Fund to help developing countries fight climate change, which will start operating in a year's time, and outlined a new world-wide agreement to halt deforestation, which alone is responsible for 20 per cent of the CO2 emissions total.
Some environmentalists criticised the deal because, in the emissions cuts it prescribes, it does not yet go far enough to keep warming to a two-degree rise. Yet there was widespread recognition that Cancun's restoration of momentum to the negotiation process, in the wake of the Copenhagen "car crash", was an achievement of great significance.
"The UN climate talks are off the life-support machine," said Tim Gore of Oxfam. "The agreement falls short of the emissions cuts that are needed, but it lays out a path to move towards them – crucially moving the world closer to the global deal that eluded the Copenhagen summit."
Wendel Trio of Greenpeace said that some people had called the process dead. "But governments have shown that they can co-operate and move forward to achieve a global deal," he said.
Britain's Secretary of State for Energy and Climate Change, Chris Huhne, who headed the UK delegation, said the agreement marked "a really important moment".
"This is a turning point in the long-running saga of international climate change negotiations," he said. "We've got a deal here which, if I had to mark it, I would have said 8 out of 10. It's way beyond what we were expecting only a few weeks ago, and, indeed, way beyond what we expecting at the beginning of the week."
Mr Huhne, who had warned that failure at Cancun would have turned future climate talks into "a zombie process" in which nothing of significance could be agreed, played a major role in the meeting's successful outcome, chairing a special group of ministers dealing with its most difficult problem.
This was a seemingly intractable argument between some rich and poor countries over renewing the Kyoto protocol, which runs out at the end of 2012, and which commits rich industrialised countries to make legally binding cuts to their emissions, while committing the poorer developing nations to do nothing. The row pitched Japan and Russia, on the one hand – refusing point-blank to countenance a renewed protocol – against developing countries led by Bolivia and Venezuela, who insisted on renewal as the price of a deal.
Mr Huhne and his group drafted text of such Byzantine subtlety that it allowed both sides to hold their positions while putting off a decision on Kyoto 2, probably to the next UN climate conference which will take place next year in Durban, South Africa.
The resolution of the Kyoto argument made possible all the rest of the package, of which the carbon-cutting measures are probably the most important, but the Green Fund and the draft of a deforestation treaty are the most eye-catching,
The fund will be used to disburse large sums in annual aid for climate defence in developing nations. Rich countries promised the fund should reach $100bn by 2020 in the Copenhagen Accord, the ad hoc agreement cobbled together by heads of state as a face-saver at the end of the failed meeting in Denmark.
The forest agreement, which is known as REDD+ – the acronym stands for Reducing Emissions from Deforestation and Degradation (plus a few other things such as replanting) – foresees the eventual "monetisation" of the great rainforests of countries such as Brazil, Congo and Indonesia, with the host nations receiving funding for not cutting them down and so releasing CO2 (perhaps eventually in the form of carbon "credits" that can be traded in emissions trading schemes).
Mr Huhne, a Liberal Democrat, was clearly elated by the success of the meeting, as were all the British team, including his Tory deputy, Greg Barker; they were particularly pleased that Britain had achieved its main objective, which was to "anchor" inside the UN climate process the informal emissions pledges made by many nations under the Copenhagen Accord, a document which, however, has no official status.
Speaking of the deal in the round, Mr Huhne said: "I think this shows that there is still a real consensus internationally – and I would say a growing consensus in places such as China and India, where you would not, a year ago, have expected it – that we do have to go down this path to a low-carbon economy, and that, actually, it is the road to prosperity."
What has been agreed?
This means the big overall picture.
The Aim An official aim, accepted by all, of halting global warming at a rise of less than 2C above pre-industrial levels (it presently stands at about 0.8C above those levels). Recognition that industrialised countries must do more. Setting a date for a global peak in carbon emissions.
The Deal The 2C target was agreed and the need for stronger action by developed countries was recognised, The idea that the world's CO2 emissions should peak was recognised – for "as soon as possible" – but no date was set.
What are we waiting for? A date for this emissions peak – 2020 was what Chris Huhne wanted – and perhaps an even tougher target than 2 degrees, such as 1.5. (Small island states threatened with sea level rise want this). A scientific review will look at this in 2013.
This means what future agreements are going to look like.
The Aim Developing countries wanted a pledge to renew the Kyoto protocol, with its commitments only on rich countries to cut their emissions. Rich countries want a universal emissions treaty binding on everyone.
The Deal A compromise in which both of these potentially irreconcilable positions were held in abeyance without wrecking the talks through clever language drafted by Chris Huhne and his team.
What are we waiting for? A second commitment period of Kyoto, with perhaps a parallel treaty legally binding everyone (which Britain would accept). A target for next year's climate conference in Durban.
This refers to the cuts in carbon emissions that countries say they will carry out
The Aim The bringing into the official UN climate change negotiating process of the pledges that many developing countries, such as China, have made over the past year under the Copenhagen Accord. This was an ad-hoc document drafted by heads of state as a face-saver at the meeting last year that has no official status.
The Deal The pledges have been brought into the UN process and documentation, or in the jargon, "anchored".
What are we waiting for? Industrialised countries, including Britain, would like to make these developing country pledges legally binding; that's some way off yet.
This refers to Monitoring, Reporting and Verification
The Aim A system by which the world community as a whole could be guaranteed that countries which claimed they were cutting their carbon emissions were actually doing so.
The Deal A softened version of the original MRV proposals that the Chinese angrily rejected as too intrusive at Copenhagen. It was drawn up by the charismatic Indian minister for the environment and forests, Jairam Ramesh.
What are we waiting for? Widespread application of monitoring.
An outline treaty to prevent deforestation because of the carbon emissions released.
The Aim Financial sticks and carrots to halt deforestation. Many countries wanted the full-scale "monetisation" of protected forests so rainforest countries could generate carbon credits and there would be a new market commodity, forest carbon.
The Deal A large-scale agreement to halt deforestation in developing countries in return for rich-world funding, but reference to market mechanisms was left out at the insistence of Bolivia. Various safeguards, including rules to protect forest peoples and wildlife.
What are we waiting for? The emissions-credits-from-forests idea is the big attraction for many investors, private and public. It will doubtless creep back in.
A new institution to channel some of the vast new flows of climate finance to the developing countries – likely to be $100bn (£63bn) annually by 2020.
The Aim To bring the fund into existence now. Developing countries wanted a big say in how it will be run.
The Deal It was brought into existence yesterday at Cancun, with the World Bank as its trustee. It has got a board, a design committee, terms of reference and a one-year deadline for it to be up and running. Developing countries are well represented.
What are we waiting for? For the fund to start lending money for climate change projects. This will probably happen after the next UN climate meeting in Durban next year.
What they said: 'It's saved the process, but not yet the climate'
"The Cancun agreement is a very significant step forward in renewing the determination of the international community to tackle climate change through multilateral action."
British Prime Minister
"Cancun marks a step forward for the international community on climate change, building on key provisions of Copenhagen."
"This has been a victory for you all, delegates. This has been a success for humanity and reason."
President of Mexico
"Responsibly, we cannot go along with a situation that my President has termed 'ecocide and genocide'."
Bolivian ambassador to the UN
"The emissions cuts on the table could still lead to a global temperature increase of up to five degrees which would be catastrophic for hundreds of millions of the world's poorest people."
Friends of the Earth
"Despite some last-minute hiccups, countries leave here with a renewed sense of goodwill and some sense of purpose."
Head of climate change, WWF-UK
"Cancun may have saved the process but it has not yet saved the climate."
"Developing countries can now see new money on the table which they can draw on to adapt to the impacts they're already facing and reduce emissions."
International Union for Conservation of Nature
"We have seen some progress on all key elements of an eventual agreement ... because there has been a much more positive atmosphere, with less hype and more realistic expectations."
Grantham Research Institute on Climate Change
"A year after the Copenhagen Accord little has changed, and 300,000 more people have died from climate change-related impacts. Another year will pass where more lives will be ruined by climate change."
World Development Movement
"It's a very weak deal – enough to keep the ongoing negotiation process alive, but not enough to save the climate."
Caroline lucas MP
Green Party leader