Well, the event yesterday at the Skeptics Society conference here in Pasadena went very well, I think. I’m not going to speculate on who “won” the debate between Ron Bailey and myself, but certainly a lot of people came up to me afterwards and thanked me for what I had to say.
I won’t give you the full rundown here, but I will provide a written out version of roughly what I had to say in my opening remarks at the debate–comments directly inspired by the “controversy” on this blog over this conference and who the keynote speakers are (Michael Crichton and John Stossel). Here are my comments (to a rough approximation; I speak improvisationally from notes so these are not the exact words):
Before I lay out my argument, I hope you will indulge me in a brief editorial comment. This is something I owe this to the readers of my blog, some of whom questioned whether I ought to speak at this event at all, given who the keynote speakers are and the likely global warming “skepticism” that they will espouse. But the point I want to make is very germane to the subject at hand as well.
I’m someone who has a long history of being a “skeptic” (at least insofar as someone who’s 28 years old can have a “long history” of anything). And I have always defined skepticism according to Carl Sagan’s famous mantra: “extraordinary claims require extraordinary evidence,” a position that I whole-heartedly embrace. However, in light of Sagan’s standard, I have been very disturbed to see the rhetoric of skepticism misapplied or misused to attack either non-extraordinary claims, or those that are in fact well-supported by strong or even extraordinary evidence.
The theory of anthropogenic global warming today is supported by very powerful evidence–interlocking data and theory across a variety of fields. You might call the level of evidentiary support for it “extraordinary.” But perhaps even more importantly, the notion that humans might contribute to global warming should not be considered an “extraordinary claim” at all today in the sense meant by Carl Sagan. In fact, given what we know about some basic principles in physics, the concept of anthropogenic global warming ought to be very easy to accept and understand.
Skeptics have a long history of going to the mat to defend Charles Darwin, whose central work, The Origin of Species, came out in 1859. What’s probably much less know to this crowd, however, is that in the same year, the Irish scientist John Tyndall gave the first more or less accurate description of the greenhouse effect. As Tyndall put it:
The solar heat possesses…the power of crossing an atmosphere; but, when the heat is absorbed by the planet, it is so changed in quality that the rays emanating from the planet cannot get with the same freedom back into space. Thus the atmosphere admits of the entrance of the solar heat, but checks its exit; and the result is a tendency to accumulate heat at the surface of the planet.
Tyndall also experimented with the radiative properties of atmospheric gases like carbon dioxide and water vapor, and found that these gases are opaque to infrared radiation emanating from the earth. There is no real scientific debate about any of this today; and from Tyndall’s insights, all else follows when it comes to human-caused global warming.
So the scientific foundation here was very well established a very long time ago. This is not, accordingly, an area where the principles of Sagan need to be applied–and indeed, “skeptics” who do so may well be abusing the rhetoric of skepticism itself.
All of that said, I am very glad that I came to this conference. The morning sessions were very serious intellectually and the scientists and others presenting did a very good job of explaining basic climate science and why we have a problem on our hands. I was very impressed with the whole show, and I want to thank Michael Shermer for inviting me to be part of it, and Ronald Bailey for a good debate.
P.S.: Off to Flagstaff now for some Henry David Thoreau type seclusion and writing; I won’t be blogging or answering email for about a week or so…
P.P.S.: If you want more details on how the debate went, Jonathan Adler has a fairly thorough rundown here. I disagree with his criticism of me, but that’s another story…