Times (UK): A STARTLING report by the United Nations climate watchdog that global warming might wipe out 40% of the Amazon rainforest was based on an unsubstantiated claim by green campaigners who had little scientific expertise. 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 …