The UN climate summit in Copenhagen has formally closed with a deal many countries admit falls far short of the action needed to tackle global warming. The non-binding accord, which the US reached with key nations including China and Brazil, "recognises" the scientific case for keeping temperature rises to no more than 2?C but does not contain commitments to emissions reductions to achieve that goal. US officials spun the deal as a "meaningful agreement" but even Barack Obama said: "This progress is not enough. We have come a long way, but we have much further to go." It is up to national parliaments to adopt the accord, after which signatories will be obliged to take measures to reduce greenhouse gas emissions and start preparing to help poor countries adapt to climate change. The intention is for a full legal agreement to be signed within a year. Gordon Brown, the British prime minister, said the agreement was a "vital first step" and accepted there was a lot more work to do to get assurances it would become a legally binding agreement. He declined to call it a "historic" conference. "This is the first step we are taking towards a green and low-carbon future for the world, steps we are taking together. But like all first steps, the steps are difficult and they are hard. I know what we really need is a legally binding treaty as quickly as possible." The deal was brokered between China, South Africa, India, Brazil and the US, but it disappointed African and other vulnerable countries that had been holding out for deeper emission cuts to hold the global temperature rise to 1.5?C this century. As widely expected all references to 1.5?C in past drafts were removed at the last minute, but more surprisingly the earlier 2050 goal of reducing global carbon dioxide emissions by 80% was also dropped. The accord achieves much wider acceptance by nations that global warming must be limited to an increase of less than 2?C. It preserves the Kyoto protocol for now. The attempt to kill Kyoto dominated Copenhagen and the resulting furore used up days of precious time, contributing to the ultimate weakness of the accord. The deal aims to provide $30bn a year for poor countries to adapt to climate change from next year to 2012, and $100bn a year by 2020 � but no details were given on its source. No specific targets for greenhouse gas cuts were stated, meaning no action to keep temperatures under a 2?C rise was set. There was no deadline for the conclusion of the climate talks, despite many leaders saying previously that six months to a year should be the maximum delay. Negotiators will now work on individual agreements such as forests, technology, and finance � but without strong leadership the chances are that it will take years to complete.