Leading article: Copenhagen: our lost chance

Perhaps our expectations were too high. Yet we should be clear about what precisely was disappointing about the accord that was reached in Copenhagen yesterday, and what was worthwhile. We have known for some months that a legally binding treaty was most unlikely. The crushing disappointment was that the undertaking to sign such a treaty by the end of next year was dropped from the final document. What was achieved in Denmark was no more than the old standby of diplomacy: agreement in principle. That principle is important, of course. For the first time, all the nations of the world accept that climate change is a problem and that they must do something about it.

That is, as veterans of the Rio-Kyoto process such as John Prescott have been pointing out, how these international agreements work. First, countries sign up in principle, then they work out the details of what should be done, by whom and who should pay. And the Copenhagen accord contains more than mere expressions of concern and good intentions – although not much more. It sets a C rise in average global temperature above the pre-Industrial-Revolution level as a target limit (although on the basis of this deal it is too late already). And it puts a figure of $100bn a year on the cash transfer to poorer countries to help mitigate a problem of the rich countries' making (although as David King points out today, the sources of this money are obscure). But, frankly, nobody needed to go to Copenhagen for that deal to be struck.

Joss Garman issues a cry from this newspaper's heart. He condemns Copenhagen as "a historic failure that will live in infamy". It certainly seems pitiful that a deal that has been two years in the making, and 12 days in face-to-face negotiation should have fallen so far short of the hopes invested in it. Yet The Independent on Sunday's head recognises the limits of the possible. The best that could have been hoped for was that China and America would have entered a competitive auction to bid each other down in their plans for a low-carbon future.

In that context, and we know it is unfashionable, we should praise Gordon Brown for having done as well as he could in difficult circumstances. It was he who came up with the $100bn figure in the first place and, as Kevin Rudd, the Australian Prime Minister, said during the talks: "I've got to say, without his intervention I doubt that we would be as close as we are at present to both a short-term and longer-term financial arrangement." Again, our Prime Minister has, on the world stage, confounded the caricature with which he is unfairly belittled at home.

But a wider deal fell through and it is important to be clear from where the opposition came. The immediate reaction against Barack Obama smacked a little of a pre-written liberal script, combining anti-Americanism with the certainty that progressive leaders will betray their cause. The real obstacle to a better deal, as Michael McCarthy reports, was China, with India hiding "behind the Chinese shadow", in the words of one participant. The US President declared a target for his country of an 80 per cent cut by 2050 – we can be doubtful about the mechanisms for achieving it, but not about its ambition. But the Chinese refused to have any targets in the accord at all – not even the targets that other countries were willing to set themselves.

This requires a rethink about the realities of geopolitics in the remaining decades of the 21st century. In the economics of carbon, we are back in a bipolar world, with China the pre-eminent power. China has moved a long way towards its green responsibility in recent years, but the failure of Copenhagen has exposed how large a gulf remains between Beijing and the rest of the world.

What was achieved last week was no more than the lowest common denominator. It was , of course, better to have a deal than no deal at all – that really would have been disastrous, but that was never likely, as it was in the interest of none of the participants for it to happen. Equally, there was never any prospect that China would agree to put a price on carbon or otherwise curtail its coal-fired energy programme in the near term.

But Wen Jiabao's obstruction went farther than that, erecting the great stonewall of China. The meagre consolation of Copenhagen is that it has been a crash course in learning how to deal with the world's new carbon superpower. If we did not know before, we know what we are up against now.