The Weekly Sift

A new study begun by skeptics from outside the climate-science community, funded in part by the climate-change-denying Koch Foundation, has published four papers supporting one of the key global-warming hypotheses.

To put this in context, there are three distinct ways to deny that we should take action on global warming.

1. Claim the planet is not getting warmer. Rick Perry has taken this approach, claiming that there is in fact a “cooling trend” that scientists have “manipulated data” to cover up.
2. Claim that the warming trend is a natural fluctuation unrelated to greenhouse gases or fossil fuels. Debunked here.
3. Claim that possible actions are too expensive. This is the hardest point to resolve, because it depends not just on climate science, but on economic projections, speculation about future technologies, and your tolerance for catastrophic risk. See the discussion here.

Shifting from one form of denial to another (depending on how much the audience knows) is a sure sign of a charlatan. Such speakers will grant that the planet is warming in one discussion, then talk about a cooling trend in the next.

The new research is a devastating blow to type-1 denial. The work was done by the Berkeley Earth Science Temperature Study (BEST), prominent scientists from outside the usual climate-science research circles (the Economist article on this mentions and physicist and an astro-physicist, including a Nobel Prize winner), who were open to the idea that climate scientists were either misguided or dishonest. So they came up with an independent way to process raw temperature readings going back 200 years. Their conclusions matched the orthodox climate-science results (warming one Centigrade degree since the 1950s) within 2%.

As BEST scientist Richard Muller wrote in Friday’s Wall Street Journal:

Global warming is real. Perhaps our results will help cool this portion of the climate debate.

I think Muller is too optimistic, as shown by the comments WSJ’s climate-denier readership appended to his article. In a rational truth-centered world, we would stop hearing type-1 denial. But in our world type-1 denial will continue, because the new study does not change the relationship between global-warming denial and fossil-fuel-company profits (diagrammed here).

ThinkProgress’ Joe Romm examines the particular case of type-1 denier Anthony Watts. Watts was supportive of the BEST study before he knew what it would say, calling their technique “a better method” and “a novel approach that handles many of the issues that have been raised”. In March Watts pledged: “I’m prepared to accept whatever result they produce, even if it proves my premise wrong.”

But now that he’s seen the result, he’s not budging. Right now he’s saying: wait for peer review. In a few months peer review will be in, and I predict he’ll come up with another excuse.

If the public debate does eventually progress to type-2 denial, here’s a handy fact to keep in mind: The hypothesis that greenhouse gases make a planet hotter isn’t some ad hoc thing left-wingers came up with to justify a government takeover of the economy. Originally, it was developed to explain a completely non-political mystery: why Venus is so hot. (I mean: why the planet Venus has a surface temperature over 800 degrees, not why the Roman love goddess is so attractive, which should be obvious. Sorry for the ambiguity.) Only later did people begin to wonder how the same phenomena played out on Earth.

Among astrophysicists, the greenhouse-gas explanation of Venus’ climate is not at all controversial (probably because no corporation owns Venusian oil rights). Given the example of the Earth’s closest cousin in the solar system, type-2 deniers need a stronger argument than mere skepticism. They need to explain why the same processes that make Venus a furnace don’t work here on Earth.

I like the way a commenter on TPM responded to type-2 denier:

Sooooo . . . help me out here. Which part is it that you doubt, the “theory” that CO2 is transparent to visible light but opaque to infrared, the “theory” that the Earth absorbs visible light and reradiates it in the infrared spectrum, or the “theory” that burning fossil carbon emits CO2?

The complete humans-cause-global-warming hypothesis may be hard to test in one experiment, but the pieces of it are simple and well-established.