The Intergovernmental Panel on Climate Change (IPCC) said in its 2007 benchmark report that even a slight change in rainfall could see swathes of the rainforest rapidly replaced by savanna grassland.

The source for its claim was a report from WWF, an environmental pressure group, which was authored by two green activists. They had based their “research” on a study published in Nature, the science journal, which did not assess rainfall but in fact looked at the impact on the forest of human activity such as logging and burning. This weekend WWF said it was launching an internal inquiry into the study.