Leading article: Better than nothing, but not much

The best that can be said of the United Nations climate change summit in Cancun is that it could have been worse. The Mexican hosts managed to produce a document that all delegates were able to sign up to. It was not the diplomatic "car crash" that our own Climate Change Secretary, Chris Huhne, warned of as the summit was nearing its conclusion.

The establishment of a Green Climate Fund to raise $100bn a year by 2020 to assist poorer nations with low-carbon development is good news. There is an outline for funding developing countries to reduce deforestation, which is responsible for 20 per cent of mankind's greenhouse gas emissions. And there was agreement on an international monitoring and verification system for emissions cuts, brokered by the impressive Indian environment minister.

But none of this can disguise the fact that there is nothing substantive in the agreement on reining in greenhouse gas emissions by either high-income or developing nations. There are no legally binding emissions cuts for any nation.

And the future of the Kyoto Protocol beyond 2012 – the one international agreement that contains any legally binding emissions cuts – remains unclear. The Russians, Canadians and Japanese who want it to be scrapped were somehow able to sign up to the same text as the developing nations who are adamant that it ought to be retained. This has been hailed as a triumph but, in truth, it is likely to be merely a battle postponed.

The memorandum states that countries should "take urgent action" to hold the increase in global temperatures to below 2C. But even the voluntary emission reduction targets, under the UN's scientific analysis, would be insufficient to achieve this. The Cancun agreement says that world CO2 emissions must soon peak. But how? The delegates wish the ends, but will not agree on the means.

A weak agreement is better than no agreement. The UN process of brokering a global deal remains just about alive. But in a warming world, the Cancun memorandum is only the coldest of comforts.