A paper from Oxford's Biodiversity Research Group says conservation groups "publicly supported" grossly exaggerated media reports in January that 1 million species could become extinct by 2050 because of global warming.
In the case of WWF, the report was used as the basis of a "conservation emergency" fundraising appeal. The paper suggests that it might have served the interests of charities to "sex up" the story as a way of generating donations.
Co-author of the paper Paul Jepson said the case showed the need for more regulation of fundraising. "Fundraisers have 'commodified' the crisis and not thought about the repercussions to the integrity of the WWF logo," he said.
The scientists say that while they empathise with the desire to galvanise public opinion on the threat to biodiversity through climate change, they warn: "Overstating the implications of preliminary research opens environmental science to damning critiques by the anti-environment lobby. This could increase public cynicism about climate change and biodiversity loss."
The claims about mass extinctions stem from a study by academics at Leeds University published in the journal Nature in January. The research said that between 15 and 37 per cent of species within a studied group could eventually face extinction as a result of climate change over the next 50 years. But this was simplified by press agencies and papers into stark warnings that a quarter of plant and animal species could be wiped out by 2050.
The academics blame Leeds University for a misleading press release, but say that NGOs, with access to teams of scientific advisers, jumped on the bandwagon when they should have known better. The paper says that groups including Friends of the Earth and WWF-UK "were quick to support the sensationalist statements".
Jepson told Third Sector: "NGOs have a duty of due diligence not just to campaign on the back of the news, but to look at the science behind it and make their own assessment."
A spokesman for WWF-UK said it was unfair to judge fundraising in the same way as academic research: "Climate change is real and it endangers species. But you have to simplify issues for appeals - there is no way you can cover all the science. Fundraising appeals are very emotional," he said.
Bryony Worthington, climate campaigner with Friends of the Earth said: "I believe our reporting of the story was justified and do not think that the Biodiversity Research Group can really claim that it constituted crying wolf, as there is potential for the worst case scenarios to be realised."