by Judith Curry
Is there or isn’t there a scientific consensus on climate change? And does it matter?
The dueling opinion pieces in the WSJ have spawned yet another insightful article. Richard Black has an article on the BBC blog entitled Climate consensus cracking open – or not. Excerpts:
In other words – in a meme that’s become very familiar over the last few years – “the consensus is cracking”.
It’s a troublesome meme in several ways.
First, and most obvious, is the absence of any evidence that it’s actually true. Certainly, since the “ClimateGate” affair there’s been criticism from within the scientific community about the practices of some climate scientists – but that’s very different from disputing their broad conclusions.
A second problem is the absence of clarity over which consensus we are talking about; consensus that the Earth is warming, consensus that greenhouse gas emissions are the main reason, or consensus that it’s a problem requiring urgent solution, to name but three?
Thirdly, is the fact that it may not matter very much.
A couple of years back, at one of the UNFCCC meetings in Bonn, I had a long chat with Viscount Monckton. As a scholar of Classics, he was able to detail with Classical derivation the reasons why consensus matters far less than simply being right.
But if the presence of a consensus is irrelevant, so, logically, is its absence; which makes the continued use by sceptics’ groups of the “consensus is cracking” meme a bit mystifying.
After all, how many times can you say it’s cracking before people start asking “so why hasn’t it cracked, then?”
In both cases – consensus and breaking consensus – it’s surely the evidence that should count, not the number of people you can get to sign your letter.
I’ve written several previous essays on the topic of consensus,
I have argued that a consensus on climate change is both unneccessary and undesirable, and that the consensus seeking process of the IPCC is having the (presumably) unintended consequence of damaging climate science and compromising the policy process.
Ward is concerned about absence of clarity over which consensus we are talking about; it seems that agreeing with the climate consensus requires supporting and endorsing the entire scope of IPCC conclusions and UNFCCC policies.
The climate community worked for 20 years to establish a consensus. The impact of the consensus probably peaked in 2006-2007, at the time of publication of the AR4. Courtesy of the CRU emails, we now understand the sausage making that went into creating the consensus. Manufacturing a consensus in the context of the IPCC has acted to hyper-politicize the scientific and policy debate, to the detriment of both. Its time to abandon the concept of consensus; consensus matters far less than simply being right and the arguments themselves that ought to be the focus for discussion.
So, here’s to ‘cracking the consensus’ in favor of open debate and discussion of policy options and in presenting carefully crafted scientific arguments that present evidence for and against, with suitable caveats about uncertainties and areas of ignorance.