In a desperate bid to help staunch the propagation of a particularly insidious meme, I offer this attempt to help clear up any confusion:
Mike Hulme and Martin Mahony of the School of Environmental Sciences University at East Anglia have a paper forthcoming in Progress in Physical Geography that explores the IPCC, “its origins and mandate; its disciplinary and geographical expertise; its governance and organisational learning; consensus and its representation of uncertainty; and its wider impact and influence on knowledge production, public discourse and policy development.”
The paper does not say that only a few dozen scientists support the idea that humans are warming the planet, no matter what blogger claims. Thanks to a certain columnist at Canada’s National Post, the notion that a leading climatologist would say just that in a peer-reviewed paper is making the rounds.
Here’s what it does say:
… knowledge that is claimed by its producers to have universal authority is received and interpreted very differently in different political and cultural settings.
The lead author, Mike Hulme, who, as I wrote recently, is getting himself a lot of attention beyond the confines of academia, released a statement today that makes his actual position on the matter quite clear:
The point of this bit of our article was to draw attention to the need for a more nuanced understanding of what an IPCC ‘consensus’ is – as I say: “Without a careful explanation about what it means, this drive for consensus can leave the IPCC vulnerable to outside criticism.” The IPCC consensus does not mean – clearly cannot possibly mean – that every scientist involved in the IPCC process agrees with every single statement in the IPCC! Some scientists involved in the IPCC did not agree with the IPCC’s projections of future sea-level. Giving the impression that the IPCC consensus means everyone agrees with everyone else – as I think some well-meaning but uninformed commentaries do (or have a tendency to do) – is unhelpful; it doesn’t reflect the uncertain, exploratory and sometimes contested nature of scientific knowledge.
The passage that is getting twisted beyond recognition is
Claims such as ‘2,500 of the world’s leading scientists have reached a consensus that human activities are having a significant influence on the climate’ are disingenuous. That particular consensus judgement, as are many others in the IPCC reports, is reached by only a few dozen experts in the specific field of detection and attribution studies; other IPCC authors are experts in other fields.
The point is, there aren’t 2500 attribution experts. Just as there aren’t 2500 Greenland ice mass experts. Nobody who understand the IPCC ever said there were, and Hulme and Mahony were noting that anyone who did wasn’t accurately representing the IPCC.
I’ll end with another excerpt from the paper. This one, too, will be offered without any context or explanation. See what you think:
But consensus-making can also lead to criticism for being too conservative, as Hansen (2007) has most visibly argued. Was the IPCC AR4 too conservative in reaching its consensus about future sea-level rise? Many glaciologists and oceanographers think they were…
h/t to Deep Climate