(Updated to recover from the deleterious effects of posting at midnight after a long day.)
(Updated even more to include this link to Curry on her own web site reacting to the Daily Mail story. She’s not happy with the headline, among other things. See at the end of the article.)
One reason I’ve been more slack about the details of current climate science controversies than I was is that I’m frankly tired of the whole thing. It’s predictable: the simplest climate post is immediately followed by the following comments from someone.
The consensus of climate science agrees that global warming is being caused by human emission of CO2. Now, the real answer to that one, frankly, is “So what?” Science isn’t established by consensus, and the number of scientific theories established by consensus that later dissolved under experimentation ranges from Aristotle’s ideas about falling bodies (obviously, heavier objects fall faster, right?) to quasicrystals — which got Danny Schechtmann dismissed as a crackpot 20 years ago and got him the Nobel Prize in Chemistry this year. This is the classical fallacy of argumentum ad populum, and the fact that it has a Latin name tells you how long it’s been recognized as a fallacy. (This is often followed by the argumentum ad baculum, appeal to force: if you keep saying that we’ll beat you up/you won’t get tenure/you should be treated as a war criminal and executed. Those don’t show up very often here at PJM, but don’t doubt I can find you examples, here and elsewhere.)
That’s usually matched with the favorite unscientific “skeptic” answers: No one has proven there’s any such thing as a greenhouse effect and the notion of a global average surface temperature isn’t even well-defined. Both of these really come down to “I don’t believe in thermodynamics at even the most basic level.” ”Scientific fact” is different in a very basic way from facts like “2+2=4″, but the basic idea of a greenhouse effect is awfully well confirmed. Among other things, it’s easy enough to calculate that the Earth’s “natural temperature” without the greenhouse effect provided by water, methane, CO2 and other greenhouse gases would be something like -33°C. If you’ve ever seen a lake or an ocean with liquid water, you have experimental confirmation of a greenhouse effect. A slightly more sophisticated version of that is the one about there not having been significant warming in the last 200 or 1000 years; again, sorry. In the 17th and 18th centuries, the Thames river regularly froze over. It has been warming. What we aren’t as sure of is precisely how much. In 200 CE there were wine grapes being grown in northern England, and about 1000 CE bread grains were being grown successfully in Greenland: it is really warmer than it was then? Doesn’t look like it — but that makes trouble for the idea that we’re warming unusually.
The global average surface temperature (GAST) objection makes at least a little more sense: it’s almost true. Since we can’t put a thermometer on every infinitestimal spot on Earth and take its temperature continuously, we’re inevitably making an approximation. But that just means we can’t take the GAST precisely. When a bunch of thermometers are averaged together, the resulting number is a temperature, and along with it (although this is often ignored) we can make an estimate of how much error there may be. There’s a major, active subtopic of mathematics called “statistics” that’s concerned with how to deal with that kind of uncertainty, its error bounds and so forth. But think of it like when you take a child’s temperature: maybe at the mouth it’s 99°F while at the other end it’s 100.1°F. You don’t claim that means taking a child’s temperature is “not well defined.” You just know it’s somewhere in that neighborhood, and you don’t worry that a boy child’s testicles are usually cooler than his pancreas.
And, of course, there’s the usual run of people who say skeptics are “in the pay of Big Oil”, “brainwashed by Fox News”, or simply “denialists” with arch connections made to Holocaust denial. The interested student is encouraged to consult a list of classical rhetorical fallacies for the Latin names for those; I promise you’ll find them all.
Perhaps the most annoying to me are the people who say The University of East Anglia cleared the scientists involved. It’s more precise to say UEA whitewashed the scientists involved; anyone who actually read the files and emails saw there was a lengthy effort to suppress opposing ideas and coerce journal editors.
For all of that, there are real, serious attempts being made to get the science right. I wrote about the preliminary results in one such case here: the Berkeley Earth Project reported that they were preparing four papers, one of which confirmed that there had been a general rise in global average earth-surface temperature over the last 200 years. The actual papers hadn’t been peer-reviewed or published, and it was, ahem, very unusual for the results to be pushed by press release before a paper had even been accepted. If a climate skeptic had done that, the derision would have been general, and would have included remarks about pseudoscience and muttered comments about cold fusion. Still, the paper itself was decent — it has a number of statistical flaws (finding that kind of thing is what peer review is for) and the results weren’t really all that dramatic — the general response was “well, duh!” It was the PR that was flawed.
Unfortunately, it’s beginning to look more and more like the PR effort was the point. Dr Judith Curry, who chairs the School of Earth and Atmospheric Sciences at the Georgia Institute of Technology and is second author on these very papers, has now gone public in an interview in the Daily Mail (UK). The story, entitled “Scientist who said climate change sceptics had been proved wrong accused of hiding truth by colleague” starts with:
It was hailed as the scientific study that ended the global warming debate once and for all – the research that, in the words of its director, ‘proved you should not be a sceptic, at least not any longer’.
Professor Richard Muller, of Berkeley University in California, and his colleagues from the Berkeley Earth Surface Temperatures project team (BEST) claimed to have shown that the planet has warmed by almost a degree centigrade since 1950 and is warming continually.
Published last week ahead of a major United Nations climate summit in Durban, South Africa, next month, their work was cited around the world as irrefutable evidence that only the most stringent measures to reduce carbon dioxide emissions can save civilisation as we know it.
[That's much stronger than the actual papers justified, as we noted here when they first came out, but a good summary of the way the results were reported in the press.]
The story goes on:
It was cited uncritically by, among others, reporters and commentators from the BBC, The Independent, The Guardian, The Economist and numerous media outlets in America.
The Washington Post said the BEST study had ‘settled the climate change debate’ and showed that anyone who remained a sceptic was committing a ‘cynical fraud’.