At a press conference last week, de Boer said that the outcome in Copenhagen made "the task to hand more urgent…the window of opportunity we have to come to grips with this issue is closing faster than it was before". But he claimed that the talks did raise climate-change issues to the highest level of government, helped to define temperature limits and financial contributions, and set 2015 as a date for reviewing whether global action needs to be more urgent.

The Copenhagen Accord, meanwhile, an agreement negotiated by China, South Africa, India, Brazil and the US, and noted by the other nations at the conference, "reflects a political consensus on the long-term global response" that is needed to climate change, according to de Boer. "We are now in a cooling off period," he added. "This gives useful time for countries to resume discussions with each other."

The morale of many is shaken. We've got an important job: one of the major tasks will be to narrow down the range of future emissions that is compatible with these policy goals. Stefan Rahmstorf

Climate scientist Stefan Rahmstorf thinks that the outcome of COP15 is depressing, but also tried to highlight some more upbeat aspects. "On the positive side: most of the actors in Copenhagen by far were quite willing to commit to a substantial effort to halt global warming – including many who were not willing to do this earlier, for example the US or Australia," he told environmentalresearchweb. "And some important developing countries have made very constructive pledges as well. We were closer than ever to major progress in fighting global warming."

Rahmstorf reckons that an agreement was not reached because "the consensus-based UN process with 192 countries is very cumbersome, and it was exceptionally badly managed at this conference", because China did not play a very constructive role and because the US was not able to offer enough. "The IPCC deemed 25–40% emissions reductions below 1990 values necessary by 2020 by developed nations to limit warming to 2 °C, and what the US offered amounted to only 4%," he explained. "This is largely a result of the lost years under previous administrations, during which the US emissions increased steeply – unlike those in Europe."

During his briefing, de Boer said that he never ceases to be amazed by the vision that some people have of the UN. "To me it is a collection of countries that have created a body to facilitate negotiation among each other," he added. "If those governments were to go and negotiate in a different setting with a different secretariat I don't know if that would fundamentally change their behaviour."

Keeping on the UN track

Both de Boer and Rahmstorf would like to see the UN process continue. "Everybody I have spoken to so far doesn't want the Accord to be a third track," said de Boer.

Rahmstorf agrees. "I hope that the multilateral UN track to a global climate agreement will not die, however cumbersome it is, because the alternatives are even worse," he said, "for example, the G20 with only the biggest emitters on the table deciding alone on climate policy, without those affected, like the small island nations, having a proper voice". In the meantime, Rahmstorf says that "while we wait for our world leaders to get their act together, there is nothing to stop us as world citizens to do all we can to reduce emissions bottom-up".

The next UNFCCC negotiating session is due to take place in late May in Bonn, with the next COP meeting set for Mexico in late November. According to de Boer, many countries feel that there is a need for an intensified negotiating schedule this year – he plans to convene the COP bureau to determine whether it's possible to slot in another set of negotiations before May.

The countries that negotiated the Copenhagen Accord – China, South Africa, India, Brazil and the US – account for around 80% of carbon emissions. "It's true to say there was not final agreement on the Accord, but an overwhelming majority supported it," said de Boer. "It was not formally adopted by COP – only noted – and we should be careful not to make it more than it is."

I never cease to be amazed by the vision that some people have of the UN. Yvo de Boer

But de Boer believes the Accord is a political tool that has broad support at a high level and that can be usefully employed in negotiations. He says the Accord is clear on a long-term goal, on how it can be measured, on financial support and on a number of new institutions that need to be established. "It can be used by us to help speed up the negotiations," he said.

Countries have until 31 January to let the UN know if they wish to be associated with the Accord in the official report of the COP15 negotiations. Industrialized countries have the option of including details of the targets they intend to commit to, while developing nations can indicate the action that they plan to take. The deadline is for administrative reasons only; the list of countries associated with the Accord will be updated on the UNFCCC secretariat website as later details come in. "It's a soft deadline, there's nothing deadly about it," said de Boer.

The climate for science

But what does this mean for the day-to-day lives of researchers? Rahmstorf believes the outcome in Copenhagen has no direct or immediate effects on climate science. "The morale of many is shaken, though," he added. "We've got an important job: since the Copenhagen Accord calls for limiting global warming to a maximum of 2 °C, possibly even 1.5 °C (this option is left open at the end of the Accord), one of the major tasks of science will be to narrow down the range of future emissions that is compatible with these policy goals."

Rahmstorf reckons that climate scientists have communicated their work quite well, particularly through the IPCC. While 2010 is the UN year of biodiversity, the biodiversity community has "not yet managed to get as much high-level attention to the biodiversity crisis; it is only now calling to set up something like the IPCC for biodiversity". On the other hand, "climate science could still do a lot better if more climate scientists get involved, take an interest in public understanding of science and educate themselves more about how to effectively work with the media". Rahmstorf reckons that "too many scientists are still stuck in the ivory tower and – for example – shrug off and ignore wrong media reports about climate science, rather than recognizing that public perception matters and that they should not leave the public debate to people with a political agenda".

The last word goes to de Boer: while the Copenhagen negotiations "didn't produce the final cake", they did leave countries "with all the key ingredients to bake a new one". Although the proof of the pudding, as they say, is in the eating.