Meanwhile, the northern hemisphere was gripped by a freezing winter – one of the coldest experienced in decades and, in the UK, last year’s predictions of a barbecue summer for 2009 had turned out to be a very damp squib. To many the idea of global warming just seemed like a bit of a joke.

This swing towards scepticism is strongly reflected in a poll carried out by Populus for BBC News in the UK, showing that the percentage of people who don’t think global warming is taking place has increased from 15% in November 2009 to 25% in February 2010. Only 26% of people thought that climate change is “now established as largely man-made”, compared with 41% in November 2009. Over in the US, a similar swing towards scepticism is thought to have occurred.

So, where did it all go wrong? What made so many people lose their trust in climate science? It is easy to blame the "Climategate" saga, but according to Jeroen van der Sluijs, a researcher from Utrecht University in the Netherlands who studies the relationship between science and society, the problems began far earlier.

In a report published by leading Dutch think-tank the Rathenau Institute, and presented to the Dutch Parliament, van der Sluijs and colleagues suggest that climate science started to become politicized well over a decade ago, via application of what they call the “linear model”.

Essentially the linear model requires certainty to justify political action and assumes that science can provide that certainty. “This has led to a tendency to present conclusions on climate risks with much more certainty than is warranted by the state of knowledge,” van der Sluijs told environmentalresearchweb. “It is this overselling of certainty that has undermined the credibility of the scientific underpinning of climate policies. It has eroded trust in its institutions.” The researchers argue that this consensus approach has hindered a full-blown, political climate debate.

Meanwhile, as the so-called Climategate scandal demonstrated, climate-change sceptics have been able to exploit the vulnerabilities of the linear model by over-emphasizing uncertainties to prevent political action from taking place.

Without a doubt it is time to change the way in which climate science is communicated and translated into policy. Van der Sluijs and colleagues suggest the “deliberative model” – based on openness about uncertainty, systematic reflection and argued choice. “Both the scientific and the political climate debate need more space and attention for diversity and uncertainty in knowledge and views,” said van der Sluijs. “This can be accomplished by offering room for dissent within climate science and communicating about it with policy makers. An excessive dependence of science and policy should also be prevented.”

Hiding behind strongly worded statements from scientific reports, such as the IPCC assessments, would no longer be acceptable. Instead, climate science would need to be presented “warts and all”, allowing everyone to judge the uncertainties for themselves.

What’s more, van der Sluijs and colleagues suggest that a greater focus on positive aspects of the challenges of climate change is important. “The climate debate could be expanded by paying attention to socially attractive development perspectives rather than doomsday scenarios only,” said van der Sluijs. “The growing focus on climate adaptation also has the power to highlight and expand the political climate debate.”

On his blog, environmental scientist Roger Pielke Junior, of the University of Colorado, Boulder, US, writes that the report gives good advice: “By placing values before science, we might realize a positive vision for the future – one that encourages robust decision making under conditions of uncertainty and ignorance.”.

Now it just remains to be seen whether the advice will be acted on.