Already it’s been a rocky ride in the pre-negotiations talks, with the expectation now that the December meeting will not lead to a legally binding agreement: proper targets are unlikely to be set until some point in 2010.

But how has science fed into this process? In March around 2500 high-level scientists gathered in Copenhagen to detail their findings since the 2007 IPCC Fourth Assessment. Anders Fogh Rasmussen, who was then Danish Prime Minister, spoke at the conference finale, stressing the tension between the certainty that politicians need to make decisions and the qualifications that scientists must make about their findings. "I need some concrete advice now," he said. "We had a very hard battle in the EU to get the 2 degree target, and now you tell me it’s not enough. I need to know and I need to know today." It could be that researchers need to tailor their climate models to produce answers more relevant to policymakers.

Scientific uncertainty has been a key issue for climate sceptics too. A typical sceptic approach will highlight, or "cherry-pick" one small aspect of climate change research that is as yet unresolved or unclear. From this it will extrapolate that the whole concept of anthropogenic climate change is a fabrication, perhaps designed to give governments an excuse to raise taxes, or scientists an opportunity to win more funding for their research.

Sceptics have had a field day in recent weeks with the leak of emails from the Climatic Research Unit at the University of East Anglia, UK. The timing of this server attack appears suspiciously like a last-ditch attempt to discredit climate change science before Copenhagen. Unit director Phil Jones’ email about repeating the "Nature trick" when handling temperature reconstruction data for the last few decades is by now notorious. At least part of the trouble seems to be that when a non-expert tries to interpret the presentation of incredibly complex scientific data, it’s very easy for a scientifically valid approach to look like an underhand manipulation. Jones has stood down temporarily from his post while an inquiry takes place.

While the wording of this and several of the other emails appears unfortunate to say the least, they were never intended for public consumption. All of which goes to show the importance of communicating clearly and openly with the public, a topic recently summarized by the University of Colorado, US, which put together a report on the latest findings into overcoming the psychological factors that can block people’s understanding of climate change science. Over at RealClimate the team has begun to compile a list of sources of climate data available to all, with the aim of showing that climate scientists have nothing to hide.

Science or society

Although scientists have highlighted the atmospheric concentrations of carbon dioxide that they believe will be needed for a given probability of limiting future climate change to two degrees, it’s up to society and politicians to decide whether they are prepared to commit to these targets. Bringing the risk of dangerous climate change down to lower levels requires increasing amounts of investment; society must decide how much it is willing to pay and what level of risk is acceptable.

In fact, some have argued that social scientists will have an increasing role to play in the field of climate change, assessing economic approaches, adaptation needs, public attitudes to the environment, and behaviour change. The Stern review, for example, analysed the economic costs of preventing climate change versus the costs of permitting it to proceed unabated.

Whatever the results of the Copenhagen negotiations, science will have an important role to play as climate change progresses. If any targets set are stringent, then hopefully the climate scientists of the future won’t have to document the most damaging changes to our planet as climate feedbacks come into play and tipping points are reached. But some further climate change is inevitable even if the Copenhagen negotiations surpass all expectations. And that means we’ll need to monitor the effects of the emissions cuts, predict whether they need to become more stringent, assess adaptation measures, monitor deforestation, size up feedback effects and the Earth’s vicinity to tipping points, keep an eye on how ecosystems are changing and any additional conservation measures they may need, and much more: the role of the climate scientist will continue to be vital.