A climate science denier of the first kind simply denies basic climate science, that, say the Earth is warming or that CO2 is a greenhouse gas. Given that both of those are basically “settled facts,” according to the U.S. National Academy of Sciences, we tend to see fewer and fewer of the CSD1s, in part because the media doesn’t take them terribly seriously. Only very famous CSD1s, like Sen. Jim Inhofe, get much press these days.

Climate science deniers of the second kind say that they accept basic climate science — so they aren’t ignored by the media — but then just assert that it isn’t going to be a big deal. They usually latch on to some tiny subset of the recent literature to make this argument. You have to cherry pick your science very carefully to be a CSD2 since as 2010 research presented at the AAAS presentation “concluded”: New scientific findings since the 2007 IPCC report are found to be more than twenty times as likely to indicate that global climate disruption is “worse than previously expected,” rather than “not as bad as previously expected.” And, of course, you have to ignore the fact that if the world actually keeps listening to CSD2s and taking no serious action to reduce carbon pollution, then worst-case scenarios are all but unavoidable (see here). I would call Bjorn Lomborg the prototypical CSD2, except that he changes his position so often it’s hard to know what he really believes now.

A climate science denier of the third kind is the rarest of all. A CSD3 says that they accept basic climate science but then starts making arguments that effectively deny that science. Indeed a CSD3 who is rhetorically clever often says he or she used to believe in climate science, but then supposedly looked into the matter closely and was shocked, shocked to learn that they had been misled. The late Michael Crichton comes to mind.

It seemed that Matt Ridley was a CSD2 based on his December Wall Street Journal piece (see Leading Scientists Debunk Ridley Piece, Even Climatologist Cited By Ridley Says He “Is Just Plain Wrong About Future Warming”).

But now in his farewell “Mind & Matter” (!!) column, he proves to be a CSD3. I can’t in good conscience waste valuable time debunking this nonsense when I could be doing something far more productive, for instance, continuing my July 4th binge-watching of “Breaking Bad” in a desperate effort to get myself up to date for the final episodes in August.

But fortunately, the great science blogger Phil Plait of Bad Astronomy has already done an awesome job. Hmm, if Walter White had a Wall Street Journal column, would it be called Bad Chemistry? I digress.

Anyway, Ridley runs the classic CSD3 scam in his article:

A decade ago, I was persuaded by two pieces of data to drop my skepticism and accept that dangerous climate change was likely. The first, based on the Vostok ice core, was a graph showing carbon dioxide and temperature varying in lock step over the last half million years. The second, the famous “hockey stick” graph, showed recent temperatures shooting up faster and higher than at any time in the past millennium.

Within a few years, however, I discovered that the first of these graphs told the opposite story from what I had inferred. In the ice cores, it is now clear that temperature drives changes in the level of carbon dioxide, not vice versa.

As for the “hockey stick” graph, it was effectively critiqued by Steven McIntyre, a Canadian businessman with a mathematical interest in climatology….

Yes, he went there. He’s essentially accusing climate scientists and the National Academy of Science of being filled with scientists who are all breaking bad.

I’ll just quote Plait at length:

Folks, let me give you a very useful piece of advice: When you hear a claim that goes against the consensus opinion of climate scientists, type that claim into Google followed by the words “skeptical science”. Because the website Skeptical Science is very thorough, and it rebuts both claims by Ridley.

First, it’s true that in the distant past (hundreds of thousands of years ago) a rise in carbon dioxide sometimes did follow a rise in temperature. As Skeptical Science points out, that’s to be expected: If the temperature goes up (which can have a number of initial causes), a lot of CO2 locked up in the oceans gets released. However, this does not mean carbon dioxide doesn’t cause warming; in fact we know an increase in CO2 causes an increase in temperature. That in turn increases the amount of CO2 released from the oceans, further increasing temperature. This is called a positive feedback loop. Happily, in general, positive feedback loops like this tend to flatten out, preventing the heat from cranking up past the point where temperatures become unstable.

Mind you, as Skeptical Science again points out, in the past most of the increase in temperature did in fact happen after an increase of atmospheric CO2. Some initial trigger caused temperatures to go up a little bit, but then the increased CO2 drove a much larger increase in temperature. Ridley is simply wrong here, and the debunking is quite easy to find online.

Still, Ridely claims that “In the ice cores, it is now clear that temperature drives changes in the level of carbon dioxide, not vice versa.” I’m puzzled by this; is he saying CO2 does not cause increased temperature in modern times? He never comes out and says this (except with that one sentence, and with the caveat “in the ice cores”), but he implies it pretty strongly. But that contradicts his stated stance that CO2 is a greenhouse gas, and humans are at least partly responsible for global warming. His position on this appears to be untenable.