Wednesday, June 16, 2010

Don't Play Silly With Science -- Even if You Disagree With It

When hackers released information showing top climate scientists fudged some data and tried to intimidate scientists who oppose their views on climate change, the American media was practically mum. So I'm not
holding my breath for coverage of this latest blip, as reported by the National Post in Toronto:

The UN's Intergovernmental Panel on Climate Change misled the press and public into believing that thousands of scientists backed its claims on manmade global warming, according to Mike Hulme, a prominent climate scientist and IPCC insider. The actual number of scientists who backed that claim was "only a few dozen experts," he states in a paper for Progress in Physical Geography, co-authored with student Martin Mahony.

Of course, given that the National Post is misreading what Hulme and Mahony wrote, it's probably best that the blip stay off the screen. The Post has done what many are guilty of -- seizing on one particular
passage in a paper and misinterpreting it badly. Here's what Hulme and Mahony write:
Consensus-making in the IPCC has been largely driven by the desire to communicate climate science coherently to a wide spectrum of policy users -- "to construct knowledge" -- but in so doing communicating uncertainties have been down-played. As Oppenheimer et al remark: "The establishment of consensus by the IPCC is no longer as critical to governments as [is] a full exploration of uncertainty.
Without a careful explanation about what it means, this drive for consensus can leave the IPCC vulnerable to outside criticism. Claims such as "2,500 of the world's leading scientists have reached a consensus that human activities are having a significant influence on climate" are disingenuous. That particular consensus judgment, as are many others in the IPCC reports, is reached only by a few dozen experts in the specific field of detection and attribution studies; other IPCC authors are experts in other fields. But consensus-making can also lead
to criticism for being too conservative, as Hansen 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, leading to what Hansen attacks as "scientific reticence."
In other words, for the guys who really understand and have unquestionable expertise in human impacts on the global environment (specifically in the field of detection and attribution studies), their numbers are understandably few. But many others with expertise in closely-related fields have studied what these experts have agreed is correct and agree with their assessment. So to say the number of experts who agree that humans are causing climate change is to ignore Hulme and Mahony's entire argument.

What's going on here is that Hulme and Mahony are lamenting past emphasis on consensus-building over efforts to study climate uncertainties. Hulme is against alarmist climate language and believes climate change is a "relative risk, not an absolute [risk]." He's a good, cautious, skeptical scientist who sees the data,  acknowledges that there are serious climate risks that been to be addressed, but also cautions that alarmism and political tomfoolery with climate change will do nothing to fix the problem, given climate research uncertainties. The rest of the paper from which the Post extracted its headline-grabber details research going on into the uncertainties Hulme and Mahony believe need to be studied.

So, shame on the National Post for doing precisely what Hulme and Mahony criticize some climate scientists and politicians for doing: alarmism.

Hulme, of course, is put off by this and many other misinterpretations of what he wrote:
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.
Those who question climate change should not indulge in the same tomfoolery they accuse the climate scientists of doing. You can't win the argument playing silly buggers like this.

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