Global Warming

It is a good idea to start on global warming with what seems to be well known. Temperatures on average have been hotter in recent decades than they were in the 1700’s and early 1800’s at least in places where we have records to compare. The most recent complete decade, the 1990’s, was particularly warm. There is a known mechanism whereby carbon dioxide in the air can contribute to warming. Throughout the last hundred and fifty years people have discharged large and usually increasing amounts of carbon dioxide into the air by burning large amounts of coal and petroleum products.

Combining these facts, it is natural to conclude that the carbon dioxide so produced has contributed to the trend to higher temperatures. And in fact there seems to be a fairly broad agreement among informed people that such is the case.

The next question of course is how large a contribution. Is the carbon dioxide from burning the sole cause of the change in climate? Is it a largely insignificant input to a trend driven by other and weightier factors? Or is it something in between? It is here that the legitimate controversy begins.

However, before talking about the legitimate controversy, it is interesting to talk about the political controversy, which is something else entirely. Opinions there range from those who are certain that human actions are not only the sole cause of the warming but in fact the only possible cause to those who dismiss the entire notion of warming as a hoax or worse. Throughout the rants and discussions, axes are ground, logs are rolled, and very little is said that is useful.

One reason for this is that neither side has a whole lot of credibility.

On the right many of the conservatives who are skeptical about global warming seem indifferent or hostile to science as such. Some of these, for example, also oppose evolution and favor notions such as creation science. Others project their disagreement with leftist policies on warming back onto the question of warming itself. It can be hard to put much trust in their scientific objectivity.

On the left you have first a large number of people who so deeply want it to be true, whose yen to regulate and control their fellow citizens’ lives is so great, that they will grab onto anything that might offer them a supposed justification for their desire, be it global warming or whatever. Then you have those who have been pulpit thumping evangelists for every bogus impending ecological apocalypse of the last forty years and have learned nothing from being wrong so often. (Even if one is afraid that the sky might fall in, he probably doesn’t want to rely on Chicken Little for the news.) Finally you have the anointed spokesman for the left’s position Al Gore – a sufficiently, consistently mendacious ignoramus that, if he were to call Brittney Spears a silly slut, reasonable people might feel compelled to at least consider the hypothesis that she is a fine and gracious lady, unfairly maligned in the press. It can be hard to put much trust in their scientific objectivity also.

So the political arguments have mainly only entertainment value.

As to the real question of how much our burning of fuels contributes to warming, I don’t know, and I don’t expect ever to know. There are two reasons for this. First it seems to be a big, hard problem that is more likely to have a statistical and probabilistic answer or set of answers than a definite one. Second, and more important, I do not know whom to trust.

Very few people are experts on, say, quantum electrodynamics or the molecular biology of enzymes or the detailed nuances of paleontology. Almost nobody is an expert on all of them. If a reasonable non-expert gets curious about one of them or some other scientific theory, he finds a good source and reads about it at a technical or popular level appropriate to his interest and background and then usually believes the results at least tentatively and provisionally -- not because he has studied every bit of data and verified every inference and calculation – but because they make sense to him and because of a broad and justified belief in the way science works. He assumes that others have studied all the data and verified the conclusions, that this has been done more than once and sometimes by people other than the authors of the theory, and that in the main those involved have behaved honestly and objectively with truth as their first objective. When he looks at a subject where there are competing theories he behaves in a similar way, looking at accounts of the different explanations, perhaps reaching a (usually very tentative) conclusion about which theory is the most plausible and best supported, acting on an assumption of the general scientific integrity of the people and processes involved . Since no one has time to become an expert on everything, this is a sensible way for people to behave.

It seems to me that this is what I cannot do on the question of how much of the warming is caused by burning fuels. I cannot do it, because the involvement of the politicians and their friends has so polluted things that I do not feel justified in assuming people’s scientific honesty and objectivity. There are too many incentives and opportunities for shading, slanting, and manipulating data and results. I really believe that it would be necessary to review the data, check the code and assumptions of the computer models, and analyze darn near everything involved oneself before reaching a defendable conclusion. That is more nearly a career than a desultory afternoon or two of study. So for now I am resigned to being permanently agnostic.

As to policy, even if burning fuels caused all the recent warming, it would in no sense justify the sort of fascistic control over the lives of others that some leftists want. On the other hand there are good and well known reasons to move away from dependence on oil, irrespective of whether the climate warms or cools or why it does. If the flap over warming helps us move to using other sources of energy in an intelligent and sensible way, we will be better off for it.