Friday, October 21st 2011, 6:34 PM EDT
The Berkeley Earth Project's new analysis of the global temperature record, which I covered on Thursday, raises a number of questions concerning the science and the politics of climate change, and the ways in which science should be conducted.
The headline conclusion - that the Earth's surface is indeed getting warmer and that the 20th Century did indeed see a pattern of warming, slight cooling and warming again - is hardly a surprise.
But in the febrile atmosphere of "the climate debate", its significance lies not only in its conclusions, but in who's done it and what they've found.
At the heart of the "Climate Gate" issue lay the allegation that researchers at the University of East Anglia (UEA) and their peers elsewhere had basically cooked the books.
They'd twisted, hidden, manipulated and otherwise distorted their record of the Earth's temperature, it was said, for whatever reason - to save their careers, promote their green ideology or further the cause of world government.
It was also said that the climate crowd were not "proper" scientists. Get physicists or geologists on the case, it was argued, and some proper conclusions might emerge.
Into this arena rode the Berkeley group - seven of the 10 physicists, two of them statisticians, just one a climatologist - with a new approach.
Richard Muller, the project's founder, told me that one of the things he looked for in choosing his team was a proven ability to take on new areas of science and bring some original thought to them.
Within climate science, one of the interesting questions now is whether the three major existing temperature record teams - Nasa, Noaa and the UK Met Office/UEA collaboration - learn anything from the Berkeley effort.
When I spoke to Phil Jones, leader of the UEA team, he told me he thought there might be ways in which the Berkeley approach could feed into existing programmes.
Equally, you can be sure that Prof Jones, James Hansen and everyone else in the established teams will be scrutinising the Berkeley methodology to see if they think it's made any mistakes.
And this leads on to the second way in which Prof Muller's team may re-shape the mould.
In the years leading up to 2009, climate researchers were subjected to an ever-increasing stream of critical bloggery, innuendo and Freedom of Information (FoI) requests.
While some of the FoI requests may have been entirely legitimate, the cumulative impact was that researchers battened down the hatches against the storms raging outside - creating something of a bunker mentality that has been criticised by official enquiries, even though they found the wider concerns about manipulation were unfounded.
Prof Muller does not come across as the sort of chap to be fazed by criticism. The project aims for openness and inclusion - not just between scientists, but involving the general public.
Perhaps it can take the big three temperature programmes back into open waters along with it. And perhaps, if it is entirely open with everything from the beginning, some of the sound and fury will abate.
Berkeley Group's animation of the change in land temperature since 1800
The Berkeley project poses a scientific challenge with its contention that water temperature changes in the north Atlantic - perhaps related to the Gulf Stream, as it's commonly known - are driving year-to-year changes in global temperature.
Even more so, when the authors suggest that a greater part of the warming-cooling-warming history of the 20th Century could be down to the Atlantic Multidecadal Oscillation (AMO) than is recognised.
(Clarification for putative cherry-pickers; the scientific work behind the papers doesn't examine this idea or even back it, but the authors suggest it as an avenue for further research.)
I had a chat with Michael Schlesinger, the University of Illinois professor who discovered the AMO along with Navin Ramankutty in 1994.
Research he and others have done since shows clearly, he said, that "while the AMO was the dominant influence on global mean temperature during 1904-1944 and 1944-1976, it is not the dominant influence over the entire observational record, 1850 to 2010.
"Over this time period, it is the increase in the concentrations of greenhouse gases caused by humanity's burning of fossil fuels that is the dominant cause of the observed warming."
That, I think, is the conclusion that the majority of climate scientists is likely to make, although the whole issue is made more complex by the fact that greenhouse warming can perturb natural cycles such as the AMO.
But there is scope for some real investigation.
In some ways, the real battle on climate change is fought not within the scientific arena but in the court of public opinion.
So it's interesting to see what those who would shape opinion are making of the Berkeley results.
The sceptical blogosphere has been unusually quiet - disappointingly quiet, you might say.
James Delingpole, Jo Nova, ClimateAudit... nothing.
One who has waded into the fray, inevitably, is Anthony Watts of Watts Up With That.
I say "inevitably", because his criticisms of weather station quality were among the factors that persuaded Prof Muller to get his project off the ground.
The Berkeley group concluded that although a high proportion of weather stations in the US might not be high quality - for example, if they're situated in the middle of an expanding city - it doesn't matter.
High-quality stations show the same warming trend as low-quality ones; so this issue can be taken off the table.
Mr Watts, in his recent postings, isn't impressed.
He argues that the Berkeley team used too long a time period for its analysis. He says it made a few other basic errors.
These things may or may not turn out to be true or important. But Mr Watts is on shaky ground, as he recognises, given that back in March he wrote a warm post on the Berkeley project's methods, concluding: "I'm prepared to accept whatever result they produce, even if it proves my premise wrong".
Pressing the point
He is on much, much, much shakier ground in his request that because the Berkeley papers have not gone through formal peer-review, the team should not be looking for any media coverage.
Pots and kettles are everywhere.
The entire modus operandi of blogging - and in the climate field, Watts Up With That is one of the most successful - is that stuff is chucked into the public domain for discussion with no review at all.
All those posts on Climate Audit and Bishop Hill over the years finding "problems" with historical climate data - how many of them were peer-reviewed?
Exactly. And Anthony Watts is in any case happy to put non-peer-reviewed science onto his pages.
On 6 October, for example, Erl Happ pens a guest post on high-level clouds and surface temperature with claims that this is new work - "The 'natural' dynamics described in this post are currently unrecognized in climate science". This wasn't peer-reviewed.
On 5 August, we find there is apparently "quite a bit of buzz surrounding a talk and pending paper" on the temporal relationship between temperature rise and CO2 - and apparently it's fine to talk about it, even though the paper's not published.
There are many other examples; and Watts Up With That is far from being alone.
Yet the Berkeley group is beyond the pale in posting and talking about science that has not been peer-reviewed?
A number of journalists in the mainstream media appear to regard Watts Up With That and other blogs of the same ilk as a gushing tap of stories - and if Mr Watts believes journalists should not report science that's not peer-reviewed, perhaps he could pick up the phone and have a word with them.
There's a fair bit of revisionism going on too, some of it visible in the comments on my news story.
"Sceptics don't say the world isn't warming," this narrative goes - "we just debate how much of it is caused by greenhouse gases."
There are some "sceptics" who do take this line, it's true. But if the Earth's temperature record wasn't an issue, why has so much energy been expended in attempting to discredit it and the scientists behind it?
Over on the other side of the divide, Joe Romm of Climate Progress, who has on several occasions written critically of the Berkeley team (Richard Muller "doesn't have a great grasp of basic climate science", Judith Curry is "the most debunked person on the science blogosphere"), is now apparently happy with their conclusions, reserving his trademark bucket of vitriol for Anthony Watts.
There is actually a more serious and interesting question surrounding peer-review, with Richard Muller describing his approach as a return to much better practices of a previous era - but that's for another time.
In the meantime, I'll leave you with the words of Elizabeth Muller, executive director of the Berkeley project, who hopes their work will "cool the debate over global warming".
What do you reckon? Chances out of 10?
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