Simon Anthony sends this report of Thomas Stocker's recent talk in Oxford.
Yesterday I attended a talk at Wolfson College, Oxford by Thomas Stocker, co-chair of the IPCC's AR5 WG1 on "Climate Change: Making the best use of scientific information". He's an intelligent, well-mannered and rational man, in a position of great influence. It's therefore all the more concerning to see the weakness of the evidence and arguments which have, it seems, convinced him of the reality and urgency of AGW and which he feels should convince everyone else.
Now one wouldn't expect the head of an IPCC working group to pour scorn on the evidence for AGW (after all, the Pope is unlikely to ask Richard Dawkins to write one of his encyclicals to the faithful). However, while nothing he had to say was novel, I think it's reasonable to assume that Prof Stocker brought along the very best evidence he had, not leaving the really good arguments back at home. So it's all the odder that what he had to say was so weak.
He told us that the IPCC's unequivocal view was that the climate had got warmer. He seemed to think that sceptics would disagree with this. (I suppose some might, but not many, so the statement rather obviously begs questions of speed, typicality and relative importance of the various causes.)
His main concern was with communicating key information so that non-specialists (public and policy makers) reached the same conclusions that he and his colleagues had. He therefore showed three graphs, of global temperature, sea level and snow cover which he thought were conclusive. The charts were all from AR4's Summary for Policy Makers and it's true they all showed the behaviour you'd expect in a warming world. Unfortunately the start dates for the data sets were 1850, 1870 and 1920 respectively, so giving no comparison with longer term behaviour and all therefore again begging the obvious questions.
He discussed the uncertainty in "forecasts" from various "scenarios" (or whatever they're called in climate science-speak) for future temperatures up to 2100. He described the difficulty in explaining the uncertainty in these "predictions" (I'm stuck in Oldspeak) due to the variations between and within the models. These included parameters, initial conditions, physical processes, natural variability, economic assumptions and so on. These factors were combined together "mathematically" and then subject to "expert" interpretation before being delivered to policy makers.
It was striking that not once did he suggest that the models' uncertainties (or "errors" in Oldspeak) should be established by comparing their "predictions" against measured data. The only sources of uncertainty with which Prof Stocker seemed concerned were between and within models. It seemed comparison with what was supposedly modelled was not relevant.
There was another troubling note in that Prof Stocker referred several times to "deniers". It was, at the very least, unfortunate that a man of such seniority should look on those who disagree with his views in such terms. It struck a discordant note from a man who otherwise seemed polite. It was also ironic in that he said that he and his colleagues mustn't respond in equivalent terms to the "provocations" of climate change deniers. (He seemed put out that he'd had to spend "several hours" responding to FOI requests. Apparently these mostly came from the UK - I don't know who's doing it, but keep it up. To his credit - or at least not adding to his debits - he did say, albeit reluctantly, that climate scientists should continue properly to respond to such requests.)
Also to his credit - or at any rate avoiding an obvious trap - in response to a question he insisted that scientists shouldn't take activist roles and shouldn't be influenced by WWF, Greenpeace or Heartland.
Something which has constantly surprised me is how otherwise intelligent and rational people can come to believe strongly in something for which the evidence is either lacking or, in some cases, absent. I suppose the most striking example is Newton who, judging by the amount of work he devoted to it, attached far more importance to alchemy than science and mathematics. I suppose in Newton's case it might have been, at least in part, because he lived quite an isolated life and didn't discuss his work much with others.
Now obviously the weakly grounded beliefs of modern climate scientists aren't in the Newtonian league (and nor, equally, is their work) but they do seem to have very strong beliefs based on weak or equivocal evidence. Of course they don't tend to spend their time in hermit-like isolation (see below) but they seldom if ever are obliged to engage directly with lucid sceptics. So I wonder if the reason for the strength of climate scientists' weakly supported beliefs is that not only are they similar to Newton in that they seldom or never face opposition, but they constantly reinforce one another's beliefs.
I also wonder (hope?) if, in some more rational future, "AGW" will be investigated mainly by psychologists as a powerful example of a recurrent and damaging aspect of human behaviour.
Oh, and this is somewhat BTW, and possibly unfair, but I looked at the website for WG1 and came across a list of the meetings and workshops for the group. The noble men and women in WG1 have, since 2009, endured travel to and stay in the following locations: Honolulu, Oslo, Venice, Geneva, Bali, Panama, Boulder, Hanoi, Kuala Lumpur, Stanford, Belgium (hmmm, someone slipped up), Geneva again, Kunming (China), Okinawa, Gold Coast (Australia), Lima, Brest, Kampala and Marrakech. They are plainly terrified of the effect of all those CO2 emissions.