The impact of global warming has been exaggerated by some scientists and there is an urgent need for more honest disclosure of the uncertainty of predictions about the rate of climate change, according to the Government’s chief scientific adviser.
John Beddington was speaking to The Times in the wake of an admission by the Intergovernmental Panel on Climate Change (IPCC) that it grossly overstated the rate at which Himalayan glaciers were receding.
Professor Beddington said that climate scientists should be less hostile to sceptics who questioned man-made global warming. He condemned scientists who refused to publish the data underpinning their reports.
He said that public confidence in climate science would be improved if there were more openness about its uncertainties, even if that meant admitting that sceptics had been right on some hotly-disputed issues.
He said: “I don’t think it’s healthy to dismiss proper scepticism. Science grows and improves in the light of criticism. There is a fundamental uncertainty about climate change prediction that can’t be changed.”
He said that the false claim in the IPCC’s 2007 report that the glaciers would disappear by 2035 had exposed a wider problem with the way that some evidence was presented.
“Certain unqualified statements have been unfortunate. We have a problem in communicating uncertainty. There’s definitely an issue there. If there wasn’t, there wouldn’t be the level of scepticism. All of these predictions have to be caveated by saying, ‘There’s a level of uncertainty about that’.”
Professor Beddington said that particular caution was needed when communicating predictions about climate change made with the help of computer models.
“It’s unchallengeable that CO2 traps heat and warms the Earth and that burning fossil fuels shoves billions of tonnes of CO2 into the atmosphere. But where you can get challenges is on the speed of change.
“When you get into large-scale climate modelling there are quite substantial uncertainties. On the rate of change and the local effects, there are uncertainties both in terms of empirical evidence and the climate models themselves.”
He said that it was wrong for scientists to refuse to disclose their data to their critics: “I think, wherever possible, we should try to ensure there is openness and that source material is available for the whole scientific community.”
He added: “There is a danger that people can manipulate the data, but the benefits from being open far outweigh that danger.”
Phil Jones, the director of the University of East Anglia’s Climatic Research Unit and a contributor to the IPCC’s reports, has been forced to stand down while an investigation takes place into leaked e-mails allegedly showing that he attempted to conceal data.
In response to one request for data Professor Jones wrote: “We have 25 or so years invested in the work. Why should I make the data available to you when your aim is to try and find something wrong with it?”
Professor Beddington said that uncertainty about some aspects of climate science should not be used as an excuse for inaction: “Some people ask why we should act when scientists say they are only 90 per cent certain about the problem. But would you get on a plane that had a 10 per cent chance of landing?”
Mike Hulme, Professor of Climate Change at the University of East Anglia, said: “Climate scientists get kudos from working on an issue in the public eye but with that kudos comes responsibility. Being open with data is part of that responsibility.”
He criticised Rajendra Pachauri, the IPCC chairman, for his dismissive response last November to research suggesting that the UN body had overstated the threat to the glaciers. Mr Pachauri described it as “voodoo science”.
Professor Hulme said: “Pachauri’s choice of words has not been good. The question of whether he is the right person to lead the IPCC is for the 193 countries who make up its governing body. It’s a political decision.”
Blowing hot and cold
Glaciers
The IPCC says its statement on melting glaciers was based on a report it misquoted by WWF, a lobby group, which took its information from a report in New Scientist based on an interview with a glaciologist who claims he was misquoted. Most glaciologists say that the Himalayan glaciers are so thick that they would take hundreds of years to melt
Sea levels
The Potsdam Institute for Climate Impact Research says sea levels could rise by 6ft by 2100, a prediction based on the 7in rise in sea levels from 1881-2001, which it attributed to a 0.7C rise in temperatures. It assumed a rise of 6.4C by 2100 would melt the Antarctic and Greenland ice sheets.
UK Climate Projections, published last year by the Government, predicted a rise of one to two feet by 2095
Arctic sea ice
Cambridge University’s Polar Ocean Physics Group has claimed that sea ice will have disappeared from the North Pole in summer by 2020. However, in the past two summers the total area of sea ice in the Arctic has grown substantially
Global temperatures
The Met Office predicts that this year is “more likely than not” to be the world’s warmest year on record. It claims the El Niño effect will join forces with the warming effect of manmade greenhouse gases.
Some scientists say that there is a warming bias in Met Office long-range forecasts which has resulted in it regularly overstating the warming trend
The impact of global warming has been exaggerated by some scientists and there is an urgent need for more honest disclosure of the uncertainty of predictions about the rate of climate change, according to the Government’s chief scientific adviser.
