Reporters feel the heat over climate change

It is now just over a year since the controversial programme The Great Global Warming Swindle was broadcast on Channel 4, but there has been no cooling in the relationship between scientists and the media. Ofcom is deliberating on whether the programme breached its code, and its upcoming verdict could have far-reaching implications for the media's coverage of climate change and other scientific issues.

The programme, produced by Martin Durkin and his company WAGtv, claimed that climate scientists had been engaged in a worldwide conspiracy to dupe the public and politicians into thinking that global warming is caused by emissions of carbon dioxide and other greenhouse gases. Instead, changes in the sun's activity should be blamed for the rise in global average temperature over the past century, the programme argued.

Loud protests followed the initial broadcast on 8 March 2007 – and its repeat on More 4 – with more than 200 complaints submitted to Ofcom. Channel 4 attempted to defend the programme by calling it a "polemic" and asserting the public's right to hear from minority views.

Scientists alleged that the programme had systematically misrepresented the research and evidence on climate change, and had only featured interviews with a fringe group of dissenting figures who did not agree with the overwhelming majority of researchers in the field. Two researchers were so outraged that they took the unprecedented step of writing a scientific paper for a leading scientific journal to explicitly rebut the TV programme's central claim about the role of the Sun.

Ofcom is due to rule on the programme in the next few weeks, but it has focused attention on how climate change is covered in parts of the national media.

The BBC, in particular, has been tying itself in knots since Jeremy Paxman alleged in an article in its in-house magazine, Ariel, last February, that the corporation had "abandoned the pretence of impartiality long ago". In June, the BBC Trust said in a report on impartiality that the corporation should allow "dissenters" on the issue to be heard because "it is not the BBC's role to close down this debate".

At the end of August, the BBC was accused by rival broadcasters at the Edinburgh International Television Festival of having a "line" on climate change, namely that global warming was caused by carbon dioxide emissions. Peter Horrocks, Head of Television News at the BBC, seemed to agree, attacking the corporation's plans for "Planet Relief", a day of programming to raise consciousness about the issue. "I absolutely don't think we should do that because it's not impartial. It's not our job to lead people and proselytise about it," said Horrocks. A month later, Planet Relief was cancelled.

Some politicians have increased the pressure on the BBC. In October, John Redwood, a senior Tory MP, attacked the Today programme in his blog for its coverage of a new scientific study, accusing the BBC of being "relentless in their insistence on climate change theory".

The controversy appears to expose a fundamental mismatch between the values of the media and scientists. On the one hand, journalists seek impartiality and balance, being used to the idea that all issues consist essentially of different viewpoints and opinions, and that what is right or wrong depends on perception. The media seeks to present two sides of an argument, and let the public decide what to believe.

On the other hand, scientists value accuracy, having been taught that different views should be assessed according to the evidence that supports them, rather than on the vehemence with which they are held. Researchers seek to present an objective view of the weight of evidence to inform the public.

The scientists point out that their understanding of climate change has developed, as in other subjects, through rational consensus – the accumulation of collective opinion in support of an accepted interpretation of the available evidence. The rational consensus on climate change is that warming of the Earth is unequivocal and very likely due to greenhouse-gas emissions and other human activities.

The existence of a consensus does not mean that there is absolute certainty or unanimity among researchers. But it is based on a large body of evidence that has been documented in many thousands of scientific papers over the past few decades. Almost none of these papers, far less than a fraction of one per cent of the total, has diverged from the consensus.

The BBC Trust report on impartiality acknowledged that "the weight of evidence no longer justifies equal space being given to the opponents of the consensus".

But it also suggested a "guiding principle" should be that "impartiality is about breadth of view and can be breached by omission", declaring that, on climate change and other issues, "as long as minority opinions are coherently and honestly expressed, the BBC must give them appropriate space".

So the BBC continues to provide a platform for dissenting viewpoints on climate-change science, even if they are not supported by evidence, arguing that it is a demonstration of the corporation's impartiality. The Great Global Warming Swindle followed the same principle by basing its entire narrative around the views of the dissenters. However, such demonstrations of balance and impartiality appear to be misleading the public. According to an Ipsos MORI opinion poll last summer, 56 per cent of people mistakenly tended to agree or strongly agree with the statement that "many leading experts still question if human activity is contributing to climate change".

Of course, broadcasters do not deserve all of the blame for the public being misled about the weight of scientific opinion on the causes of climate change. The Daily Mail has published many opinion pieces suggesting that climate-change science is wrong, or even an anti-American conspiracy, and The Sunday Telegraph includes attacks by its columnists on the rational consensus almost every week.

Journalists understandably feel they should seek balance and impartiality in their reporting. But scientists will remain frustrated by this approach as long as it appears to undermine the accuracy of the media coverage of climate-change science.

Bob Ward is Director of Global Science Networks at Risk Management Solutions, but the views expressed in this article are his own.