Wednesday, May 16, 2007


Global Warming, Global Stifling
... Most of the theses in the Grand Theory are packed with morally charged concepts. If an epidemiologist says, "The chance of bird flu becoming epidemic is growing significantly," she is making a narrowly scientific statement. If she says, "Bird flu is about to explode catastrophically! We have to stop it now!", she is going beyond science to make a moral and a policy judgment. That isn't a problem if the economics and morality are obvious — if, say, the cost of inoculation is trivial compared to the costs associated with a disease that has a mortality rate of nearly 50%. But when the economics is complex (with costs and benefits hard to measure, the range of options large, and the chances and scale of an anticipated event hard to estimate), or when the moral case is unclear (say, when the moral values being balanced are incommensurable with one another), such value-laden language is dangerous.

Mike Hulme, director of the Tyndall Centre for Climate Change, an eminent specialist who is favorable to the Narrow Theory, made this point well in a recent interview with the BBC. He said, "Why is it not just campaigners, but politicians and scientists, too, who are openly confusing the language of fear, terror, and disaster with the careful hedging which surrounds science's predictions? . . . To state that climate change will be 'catastrophic' hides a cascade of value-laden assumptions which do not emerge from empirical or theoretical science."

The second distinction I want to make is between general agreement, at least among the scientists in a given field, and a complete convergence of opinion. When the majority of scientists agree that a theory in their domain is true, there is general agreement. But general agreement means that a significant minority of scientists still dissents. When a theory has survived repeated tests (i.e., has predicted with great accuracy phenomena that are then confirmed empirically) and has been tremendously fruitful in guiding research, then virtually all scientists active in its domain agree, and there is complete convergence. Ask physicists whether quantum theory is true, and 99.99% will say it is. You would see the same virtual unanimity if you asked biologists whether all life on this planet evolved from one original form.

There is general agreement about the Narrow Theory — though there are varying degrees of this agreement, depending on the particular thesis being considered. The summary of the UN study just released (the Fourth Intergovernmental Panel on Climate Change or "IPCC") reports that its panel is over 90% certain that the "observed increase in globally averaged temperatures since the mid-20th century is . . . due to the observed increase in anthropogenic greenhouse gas concentrations." This means that a significant minority of the rele-vant scientists continues to doubt part or all of the Narrow Theory — perhaps a larger minority than is apparent, since the summary is often more "confident" than the actual study, and even more since the report's contributors were selected by politicians whose desire for scientific objectivity may not have been paramount. And although the highest percentage agrees that temperatures have risen (Thesis 1), there are prominent dissenters. Atmospheric physicist S. Fred Singer questions Thesis 1. So do eminent climatologist Timothy Ball, and Neil Frank, former director of the National Hurricane Center. Climatologist William Gray of Colorado State University actually predicts global cooling — which, remember, was the dominant climatological prediction of the 1970s.

Fewer scientists agree that the rise was caused by human activity (Thesis 2), or that the potential ecological damage will include such threats as increased storm activity (often cited by supporters of Thesis 3). Much of the disagreement about Thesis 2 surrounds the question of whether the global warming posited by Thesis 1 is primarily or only partially caused by human fossil-fuel use. After all, methane is a greenhouse gas, and is emitted by cattle in large quantities, so it is caused by man, but not by the burning of fossil fuel. Then again, volcanoes and other natural processes create copious amounts of CO2.

Some scientists, such as Dr. Willie Soon of the Harvard-Smithsonian Center for Astrophysics, believe that the rise is caused by a rise in solar radiation, a cyclical pattern that they see going far back in geologic history. This explanation has the advantage of providing a reason for periods of global warming (and cooling) before human existence. Other climatologists point out that the geological record shows that some past rises in CO2 were preceded by temperature rises, and thus could not have been causes of those temperature increases. There must have been a different cause (such as increased solar radiation). Another recent theory is that temperature fluctuations may be caused by increased cloud formation resulting from increased cosmic radiation. And prominent Narrow Theory critic Richard Lindzen (a meteorologist at MIT) disputes whether rising temperatures will increase storm activity.

I am not a climate scientist. I do not know if complete convergence among climate scientists will ever occur, or if it does, whether it will be convergence on all three theses, or fewer. But I don't have to be a climate scientist to see that there is at present nothing approaching complete convergence on the Narrow Theory.

Turn to the Grand Theory, and things get very curious. While there seems to be a preponderance (though nowhere near a complete convergence) of opinion on the Narrow Theory, there isn't even anything approaching a consensus on the Grand Theory. For instance, an NREP (National Registry of Environmental Professionals) survey of licensed environmental specialists shows that only 66% consider the rate of global warming a serious problem facing the planet (with roughly the same percentage believing that the U.S. should do more to address the issue), and that only 39% consider regulation of carbon emissions as the most important tool in addressing global warming.

Nevertheless, it appears that many climatologists give evidence for the Narrow Theory — usually by showing that the carbon dioxide building up in the atmosphere has a human stamp — but then essentially assume that all the other theses of the Grand Theory follow automatically.

This doesn't surprise me, because, again, most of the other theses of the Grand Theory are economic or even moral, hence not in the climatologists' domain of expertise. Such things frequently happen with multi-domain metanarratives. Because the experts in one field (say, atmospheric physics) don't know much about another field (say, agricultural economics), they can't agree or disagree with the experts in that field in any meaningful way. This is why these metanarratives are more often put forward by advocacy groups than by groups of scientists reasoning as scientists....