I had a recent exchange with a global warming skeptic named Bruce Hall, first in the comments section on Economist’s View, then in an email exchange. We were polite, amidst a certain degree of rancor, and that made the exchange pleasant enough that the “agree to disagree” option came up from the magic 8 ball. (But let it be acknowledged that I did give in to snarkiness with a few other posters, who rubbed me more the wrong way, so I guess I can’t claim politeness as my inevitable demeanor). Part of the exchange was some historical background, which I’m expanding a bit here.
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One of the claims sometimes made by global warming skeptics is that there was a time in the 1950s (or sometimes it’s said to have been in the 1970s), that there was a time when scientists were warning about an impending ice age. But, there was never a general scientific consensus, in the 1950s or any other time, that a new ice age was imminent. There was, of course, the recognition that we are currently in what is called an "interglacial" period, and that, other things being equal, another ice age would eventually return. However, the greenhouse gas hypothesis has been around for over a century now, and the CO2 readings from Mauna Loa in the mid-50s caught a lot of people's attention, with some pretty explicit greenhouse warnings dating back at least that far. Indeed, I saw one in an editorial in Analog. One the other hand, there was a cooling trend in the middle of the 20th Century. That was one reason for a lack of consensus about greenhouse warming.
There is now what I’d call at least a plurality of belief among climatologists that what was going on with mid-century climate was that the great increase in the use of high sulfur coal to generate electric power actually did have an aerosol cooling effect, at least on a local or regional basis. Climatologists are also very aware that there is a measurement bias in surface temperature readings, because so many are on land and so few at sea. Again, another reason why a consensus was slow to develop.
(As an aside, I'll note that there was a Fritz Leiber story in the 1940s, "Destiny Times Three" that presented a view of an ice age as a result of a nuclear war, not from "nuclear winter" but rather because enough of the Earth's lower crust had been exposed that rock weathering had removed so much CO2 from the atmosphere that "global cooling" resulted. I think that this was the first appearance of the greenhouse hypothesis in science fiction).
Now it so happens that I was a global warming skeptic for probably longer than I should have been, in retrospect. There were several things that changed my mind. One was that, in the late 80s and early 90s, James Hansen made a very persuasive case, including some spot on model predictions of the effects of the Pinatubo Eruption. Just as important was the paper by David J. Thompson in Science in 1995 that found a season change signal (actually a "flipping" local climates to more resemble a Mediterranean seasonal pattern), that dates back over a century.
(It’s interesting that, while checking on the date of the Thompson paper, I came across an article arguing that what Thompson was showing was a good thing. After all, who wouldn’t want an earlier spring? Why wouldn’t Labrador prefer to have a climate more like Spain? One might also ask why we shouldn’t want to get rid of all that ugly ice in Greenland. Lush forests would be much prettier than ice caps, if it weren’t for the fact that Florida would then be underwater.)
Anyway, Thompson’s point was that greenhouse gases had, in fact, been changing climate during all the time that climatologists had been wondering why greenhouse gases weren’t changing climate. Now I will admit that the statistical methods that Thompson used are pretty arcane, and I wouldn’t blame anyone who didn’t undergo a similar “conversion reaction” as I did. I am trained in both advanced statistics and ecological modeling, however, and I found Thompson’s paper both persuasive and disturbing.
The other part of my "conversion" as it were, has more to do with philosophy. First, uncertainty is not our friend. To say that some potentially catastrophic global phenomenon is uncertain does not reduce the degree to which we should be concerned; if anything, it should increase our concern, because we do not have any better a handle on the downside potential than we have on the economic costs of reducing CO2 emissions. In fact, we have less of an idea of the potential future costs of climate change.
Secondly, in the most fundamental way, this is a matter of rights. No one has the right to change the nature of the air you and I breathe, nor does anyone have the right to change global climate (or, pacé Thompson, regional ecosystems). Yet the first is undeniably happening, and the evidence of the second is very strong, strong enough to have produced a real scientific consensus on its existence, if not its magnitude.
One might argue for the "rights" of people to conduct economic activities, to buy and sell goods, to burn coal, oil, or gas from their own property etc., but in fact, the massive emissions of CO2 that are currently occurring are due to organizational behavior, not the sum of individual behaviors. Governments set policies, with other large organizations such as corporations influencing and benefiting from those policies. And no matter what some libertarians might think, corporations are not simply "private;" they enjoy all manner of special, legally (i.e. governmentally) derived privileges. Also, and maybe even more to the point, corporations have much more influence over specific parts of public policy than do mere individuals.
Finally, there are large amounts of money being spent on what amount to disinformation campaigns of the sort noted in the EV thread. I know, for example, S. Fred Singer; I have read what he has written for the popular press, what he has managed to insert into technical publications via the comment process, and what he has testified to before congress. Singer is a perfect example of one of the "liars and charlatans" that the EV thread referred to, and anyone dealing with the issue needs to understand just how mendacious some of the actors are. If you delve far enough into the background of much of the global warming skeptic literature, you'll find Singer and his Science & Environmental Policy Project. Singer is one of those people that, if you ever find yourself on his side in an argument, you need to check your bearings very carefully. And Singer has been against the theory of stratospheric ozone depletion, global warming, and the dangers of cigarette smoke and indoor air pollution. As I say, if you find yourself agreeing with Singer, take a careful look around at the company you’re keeping.
Finally, Mr. Hall mentioned nuclear power, as a non-greenhouse gas emitting power source. I'm actually a fan of what are called "accelerator driven spallation reactors," partly because they are so technically spiffy. However, nuclear power is another absolutely socialist enterprise; it requires massive government interference in the market for any form of nuclear power to be feasible (at the very least, standard insurance and liability requirements must be totally revised for the benefit of a nuclear industry), and it doesn't look to me like our country does a very good job at socialist enterprises, so it doesn't seem like that good a deal for our circumstances. One need only look at the absolute mess that has been made of the nuclear waste disposal process in this country to get the feeling that maybe we need to be looking at some other way out.
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