Robert Watson, som ledet FNs Klimapanel fra 1997 til 2002, advarer nå og sier panelets troverdighet står på spill. En ny alvorlig prediksjon viser seg å være dårlig fundert: at avlingene i Afrika kan synke med så mye som 50 % allerede innen 2020.
Det er en prediksjon den sittende IPCC-leder, Rajendra Pachauri, og FNs generalsekretær Ban Ki-moon har gjentatt ved flere anledninger.
Robert Watson, chief scientist at Defra, the environment ministry, who chaired the Intergovernmental Panel on Climate Change (IPCC) from 1997 to 2002, was speaking after more potential inaccuracies emerged in the IPCC’s 2007 benchmark report on global warming.
The most important is a claim that global warming could cut rain-fed north African crop production by up to 50% by 2020, a remarkably short time for such a dramatic change. The claim has been quoted in speeches by Rajendra Pachauri, the IPCC chairman, and by Ban Ki-moon, the UN secretary-general.
This weekend Professor Chris Field, the new lead author of the IPCC’s climate impacts team, told The Sunday Times that he could find nothing in the report to support the claim. The revelation follows the IPCC’s retraction of a claim that the Himalayan glaciers might all melt by 2035.
The African claims could be even more embarrassing for the IPCC because they appear not only in its report on climate change impacts but, unlike the glaciers claim, are also repeated in its Synthesis Report.
This report is the IPCC’s most politically sensitive publication, distilling its most important science into a form accessible to politicians and policy makers. Its lead authors include Pachauri himself.
In it he wrote: «By 2020, in some countries, yields from rain-fed agriculture could be reduced by up to 50%. Agricultural production, including access to food, in many African countries is projected to be severely compromised.» The same claims have since been cited in speeches to world leaders by Pachauri and Ban.
Speaking this weekend, Field said: «I was not an author on the Synthesis Report but on reading it I cannot find support for the statement about African crop yield declines.»
Watson said such claims should be based on hard evidence. «Any such projection should be based on peer-reviewed literature from computer modelling of how agricultural yields would respond to climate change. I can see no such data supporting the IPCC report,» he said.
Igjen dreier det seg om en rapport som ikke er blitt vurdert av fagfeller. I dette tilfelle en marokkansk klimaekspert Al Agoumi. Han skrev en rapport til en canadisk tenke-tank.