sexta-feira, fevereiro 19, 2010

Clima e ciência - a perspectiva da Economist sobre o Climate gate

No Economist online, uma boa súmula do que é a tempestade à volta do IPCC (na minha modesta opinião,

Climate change and the media / Feb 17th 2010, 19:34 by M.S.
LAST week members of the Dutch parliament denounced the Intergovernmental Panel on Climate Change for including in its mammoth 2007 report the scandalous charge that 55% of the Netherlands is below sea level. This outrageous misinformation had been supplied to the IPCC by...the Netherlands Environmental Assessment Agency, the Dutch government's national institute for environmental planning. In fact 26% of the country is below sea level, with another 29% merely "at risk of flooding", according to a correction the Dutch agency has now published. In an article in the Dutch magazine Vrij Nederland, agency official Joop Oude Lohuis does not quite make it clear whether his agency supplied the incorrect figure, or whether he thinks
someone at the IPCC mistakenly added the two numbers.

A few weeks ago it was unearthed, to everyone's great relief, that the IPCC report was wrong to have stated that the Himalayan glaciers might be gone by 2035. Since then the hunt has been on for errors in the report, and a number of accusations have followed. According to the climate scientists at RealClimate, the incorrect Dutch sea-level statistic is the one that comes closest to being an actual error. An assessment that rain-fed crop yields in some African countries "could be reduced by up to 50%" is based on legitimate research, and is followed in the report by the qualifier that some other climate changes may be beneficial. A claim that up to 40% of the Amazonian rainforest could be subject to die-off due to relatively small changes in precipitation is similarly legitimate. A chart showing economic damages from climate change should not have been included in the report's supplementary materials, say the researchers whose work it is based on. But otherwise they say the IPCC has accurately represented their work.

Increasing scrutiny has shown that there is certainly room for improvement and reforms at the IPCC. But what we also see with several of these scandalous "errors", is that the IPCC's claims as reported by the mainstream media were often exaggerated. For example, while I have a general sense of a few of the broad conclusions of the IPCC's 2007 report (like a sea level rise most likely around 30 centimeters by 2100, though more recent research indicates it will probably be much more), I couldn't name many specific details. But I knew the IPCC had estimated the Himalayan glaciers would be gone by 2035 long before that estimate turned out to be false. I knew this because the mainstream media had plucked that claim out and reported it
widely, because it was so sensational. It's also perfectly understandable that elements in the report indicating very high possible levels of crop damage in certain African countries would be reported by the media without
the qualifying considerations. It would be routine and accepted practice for such an assessment to be reported in a wire-service story with the headline: "IPCC predicts 50% crop reductions in Africa".

The media like big numbers. Reporters will naturally take a 3,000-page report like that of the IPCC and skim through it, looking for affected populations over 1 billion, percentages over 50%, and catastrophes occurring within the next 30 years. The resulting picture in the media will exaggerate the results of the scientific research. In some cases, scientists who work on climate-change issues, and those who put together the IPCC report, must be truly exasperated to have watched the media first exaggerate aspects of their report, and then accuse the IPCC of responsibility for the media's exaggerations."

2 comentários:

Anónimo disse...

Anónimo disse...

Com o frio que tenho em casa dava-me jeito um bocadinho de aquecimento global...