08/12/2011 07:02 GMT | Updated 07/02/2012 05:12 GMT

Is Accuracy Being Frozen Out of the BBC's Climate Change Coverage?

While the world's governments have been gathered in Durban, South Africa, between 29 November and 9 December to discuss co-ordinated international action against climate change, many TV viewers in the UK on 7 December were transfixed by powerful images of how warming is transforming the Earth's polar regions.

The final episode of Frozen Planet featured narrator Sir David Attenborough at centre stage as he explained the ways in which shrinking ice sheets and other impacts in the Arctic and Antarctic are radically changing life at the poles for all species, including humans.

But the seventh instalment of the BBC's extraordinarily successful series, called On Thin Ice, has attracted undeserved controversy for its focus on the impacts of climate change.

First, the Daily Telegraph newspaper reported that some broadcasters in other countries that have bought the series, particularly the United States, will not be showing the final programme because of its content.

Caroline Torrance, the Director of Programme Investment at BBC Worldwide, offered a plausible, if not entirely convincing, denial, pointing out that "the vast majority of broadcasters have licensed the Frozen Planet: On Thin Ice episode".

However, an even bigger stir was caused by this week's issue of Radio Times which offered Lord Lawson, the chair of the 'sceptic' Global Warming Policy Foundation, the opportunity to 'balance' the clear and stark messages conveyed by Frozen Planet. Lord Lawson attacked Sir David Attenborough, alleging that "when it comes to global warming he seems to prefer sensation to objectivity".

But in attempting to substantiate his accusations against Sir David, Lord Lawson merely demonstrated that the Radio Times did not bother to fact-check his article.

First, Lord Lawson attempted to create a false balance between the dramatic shrinking of the Arctic ice cap and the increase in sea ice in some parts of East Antarctica. What he failed to mention is that the mass of ice across Antarctica as a whole is declining, and sea ice is increasing in those areas of East Antarctica that are experiencing abnormally low temperatures because of the man-made hole in the ozone layer.

Second, Lord Lawson claimed that the polar bear population in the Arctic has been rising. This is untrue. As the new 'Arctic Report Card: Update for 2011' indicates, of the 19 sub-populations of polar bears, only one has recorded an increase while 7 have recorded decreases.

Third, Lord Lawson suggested that increased evaporation from the Arctic Ocean will increase cloud cover that will counteract the impact of global warming. In fact, the temperature of the Arctic is rising faster than regions at lower latitudes, and the loss of albedo caused by the melting of the ice cap, which tends to reflect the Sun's rays, is increasing warming.

Fourth, Lord Lawson asserted that global warming stopped in 2001, but his argument was based on an apparently weak grasp of statistics. If one analyses each of the 32 sequences of 10 consecutive years (including 2001 to 2010) of global annual temperatures that occurred between 1970 and 2010, only seven define statistically significant (at the 95% level) warming trends, even though the trend over the entire 41 year period is clearly upwards and statistically significant. Measuring trends from just 10 data points carries the serious risk of failing to detect statistically significant signals amid the noise.

One should perhaps admire the chutzpah of Lord Lawson's claims of bias, given that the campaign by the Global Warming Policy Foundation against UK Government policies on energy and climate change relies so heavily on promoting inaccurate and misleading information about the science.

What is very disappointing is that the Radio Times has ignored a report which criticised the disproportionately large amount of coverage that climate change 'sceptics' have received from the BBC.

Perhaps this is a consequence of the BBC Trust abandoning its plans to promote the report because Lord Lawson threatened legal action over a sentence which accused him of making statements that are not supported by the facts.

Whatever the reason, the BBC must not be cowed by fringe campaign groups which stridently believe that impartiality should trump accuracy and which insist that the broadcaster must position itself halfway between scientific facts and 'sceptic' fictions. The Global Warming Policy Foundation on 8 December again put pressure on the BBC to give in to its demands when it published a report by Christopher Booker, a columnist for the Sunday Telegraph newspaper, attacking the broadcaster's coverage of climate change.

Nevertheless, the BBC should resist this lobbying and should instead follow the outstanding example set by Sir David Attenborough, whose reputation remains unimpeachable, by continuing to promote public awareness and informed debate about the risks posed by climate change.

Bob Ward is policy and communications director at the Grantham Research Institute on Climate Change and the Environment at London School of Economics and Political Science.