AS DAWN heralded Saturday morning in Montreal, the latest international climate conference closed in a mood of euphoria. There were tears in the corridors. The UK's environment secretary Margaret Beckett proclaimed a "diplomatic triumph" in which she had achieved all that she had hoped for. Even normally hard-boiled environmental campaigners and journalists were misty-eyed. "Historic," said Greenpeace. "A big step forward...the US has been shamed," said The Guardian in London (see "Small green victory").

Get a grip. Last-minute deals are always exciting, especially after overnight negotiations. But in the cold light of day we have to ask what exactly was achieved. The answer looks like little more than an agreement to carry on talking - and even that is hedged in places by promises to talk about very little that is meaningful.

Meanwhile, every square metre of the planet's surface is absorbing about 1 watt more heat than it can release into space. That may be only slightly more than the power of a Christmas tree light bulb. But it matters.

So what was decided? First, the meeting shifted a backlog of technical matters that will allow the Kyoto protocol to come into force, such as letting rich countries earn carbon credits by financing green schemes in poor nations. Victory has been declared on these matters so often in the past that it is hard to be sure. But since there is now agreement on penalties for countries that miss their targets for the first compliance period, from 2008 to 2012, it probably is a done deal. So the talks moved on to what happens after 2012.

Countries that have ratified the Kyoto protocol agreed to begin talks aimed at reaching agreement "as soon as possible" on targets for a post-2012 compliance period. This was vital, not least because it signals to industry that it can profit for the foreseeable future by cutting carbon dioxide emissions and trading carbon credits. But it is hard to justify it as a "diplomatic triumph" when the protocol had already committed signatories to beginning those talks before 2006.

Third, and most tortuously, the meeting agreed to begin an "open and non-binding dialogue" on how those without Kyoto targets - ranging from opt-outs in Washington and Canberra to fast-developing countries like Brazil and China - might contribute to cutting greenhouse gas emissions. This was the bit that nearly derailed the Montreal talks. The US walked out because it feared being pressured during this "dialogue" to make commitments on emissions. It rejoined not because of a change of heart, nor even because of a lecture by Bill Clinton, but after winning a stipulation that the dialogue "will not open any negotiations leading to new commitments". The White House wasn't shamed: it won.

The Montreal talks were no disaster, it is true. But they were certainly no triumph. It was sad to see environmentalists who have been on the case longer than most of the politicians getting caught up in the euphoria. Greenpeace's Steve Sawyer echoed Beckett in claiming the talks had delivered "just about everything" he wanted. What kind of world does he advocate?

With green groups playing politics, scientists seem to stand alone. In recent months, they have reported compelling evidence that climate change is a real and present danger, and that the global climate system may be on the brink of dangerous positive feedbacks. We may face runaway melting of Arctic sea ice, a shutdown of global ocean circulation systems, massive methane releases from melting permafrost, stronger hurricanes and "megadroughts" from northern China to the American west.

These are not abstract outputs from computer models but things that are starting to happen. At this magazine we regularly meet climate and Earth-system scientists who harbour real fears for themselves and their families about what the 21st century will bring. Jim Hansen, director of NASA's Goddard Institute for Space Studies and George Bush's top climate modeller, is not alone in thinking that we have, as he said last week, "at most 10 years" to make the drastic cuts in emissions that might head off climatic convulsions.ย“We have at most 10 years to make the drastic cuts in carbon emissions that will head off climate convulsionsย”

Back in 1997, the newly agreed Kyoto protocol was correctly hailed as a first step to a safer world. Eight years later we still await the second step. Montreal, for all the tears and supposed triumphs, was not it.