Climate change report controversy

THE MOST recent report by the Intergovernmental Panel on Climate Change (IPCC) was castigated in sections of the press for publishing unsubstantiated data and misleading the public about the dangers of global warming. The newspapers doing this were well-known climate change deniers. But, in the aftermath of the climategate row – following the release of hacked emails from the Climate Research Unit (CRU) of the University of East Anglia – their claims were given wide prominence, since there is significant public scepticism about science and scientists.

New Scientist magazine analysed the report and the reliability of the data on which it was based. Significantly, it found that the section on the physical science of climate change, rather than on its effects, went largely unchallenged, even by the climate sceptic press. The controversial part of the report was on the predictions that were made on the likely effects of global warming, in particular regarding water supply, food and bio-diversity. On the latter, the IPCC made the claim that 20-30% of plant and animal species face extinction if temperature rises exceed 1.5-2.5 degrees Centigrade above present levels. This figure, however, was based on only one scientific paper that predicted global changes. The rest of the data was derived by the IPCC from other studies that merely looked at regional figures or those for particular species. Also, the methodology of the paper on global changes was criticised in several subsequent papers. Nonetheless, when the authors of these critical articles were contacted, none objected to the IPCC findings and one said that its conclusions were too cautious.

In addition to the New Scientist, the Oxburgh review analysed eleven key scientific papers produced by the CRU over the last 20 years, including key findings on global warming used in several IPCC reports. Lord Oxburgh commented that there was "absolutely no evidence of any impropriety whatsoever… Whatever was said in the emails, the basic science seems to have been done fairly and properly". (The Guardian, 15 April) The review did, however, raise concern over record-keeping and some presentational aspects. A third and final report is due in May.

On the other two areas scrutinised, food and water supply, New Scientist found that there was evidence that the conclusions reached were unjustified and somewhat exaggerated. On the effects of climate change on drought in Africa, for instance, it was stated that an average of 152 million people would suffer from increased ‘water stress’. This conclusion ignored other available data from the same cited paper that showed increased access to water in some African regions. The IPCC report also did not reflect the warning in the paper not to take its projections too literally. There were similar problems with the part of the IPCC report dealing with food, in particular in the projections for crop yields in Africa, where it was stated that yields in some countries could be reduced by 50% by 2020.

The research quoted in the report had not been peer reviewed for accuracy and validity by other scientists, as would usually be the case, which casts doubt on the reliability of its conclusions. Not being peer reviewed does not necessarily mean findings are wrong, but New Scientist also found other problems. The research only referred to crop yields in rain-fed regions of Africa, whereas in large areas of the north of the continent crops are irrigated rather than rain-fed. The IPCC ignored this distinction, which undermined the validity of its headline conclusion of a 50% fall in yields. Other criticisms that were given press prominence were found to reflect more minor errors, such as the statement that 55% of the Netherlands is below sea-level, rather than 55% will be at risk of flooding.

The public scepticism about science, that allowed sections of the climate-change denying media to exaggerate, sometimes hysterically, the errors in the IPCC report, is ultimately a reflection of a crisis of legitimacy of bourgeois society, whose causes there is no space to address here. Public scepticism, to an extent understandable, means that advocates of action on climate change must be very careful not to lay themselves open to allegations of bias or misrepresentation. In particular, predictions of the future effects of global warming must be treated very carefully, as Socialism Today always tries to do, since current models cannot predict with great accuracy events decades in the future. However, it is still absolutely clear that climate-change effects will be extremely serious, made even more worrying by their relative unpredictability.

Pete Dickenson