New York Times Magazine, July 8, 2007

MORE HEAT THAN LIGHT

[Rachel's introduction: Here is a recent attack on the precautionary principle that appeared in the New York Times. The author says applying the precautionary principle to global warming might result in a reduced rate of economic growth. Therefore, he says, instead of taxing carbon to try to reduce greenhouse gas emissions, we might be better off spending our money designing new crops that can withstand hotter temperatures, and creating "new water supplies," though he does not say where "new water supplies" might come from.]

By Gary Rosen

If you happened to be in suburban New Jersey this past Jan. 6, you may recall that it was hot -- 72 degrees, to be exact, a record-breaking high. I remember that winter Saturday because, amazingly, I got to spend it in shorts and a T-shirt, playing a sweaty game of Wiffle ball with my sons in our backyard. A more recent Saturday, June 23, was also unusual, but for its unseasonable coolness, not its heat. The temperature that night dropped into the mid-50s, leaving us to shiver under our cotton blankets.

But the big difference between these two weather events wasn't the direction the thermometer jumped. It was how people reacted to them. In my corner of blue-state America, that balmy day in January elicited lots of muttering about evil Republicans and their indifference to greenhouse gases. In June, by contrast, I didn't hear a word about the evidentiary significance of our cold spell. Didn't goose bumps in summer mean that Al Gore is wrong? Well, no; but why the different standard for unexpected heat in January?

I have to confess to a serious case of global-warming fatigue. I know that the planet is heating up and that fossil fuels are the likely culprit. But I'm tired of the sanctimony and the alarmism that surround the subject. Every temperature spike is not a portent of the apocalypse, and the need to see it that way keeps us from dealing rationally with the problem itself. The issue is climate change, after all, not weather change. What scientists worry about isn't the occasional winter scorcher but the long-term shift in average temperatures.

Actual global warming over the past century amounts to just over 1 degree Fahrenheit. The United Nations-sponsored Intergovernmental Panel on Climate Change predicts that the continued buildup of atmospheric CO2 could make the Earth 3.5 to 8 degrees warmer by 2100, with potentially severe consequences for agriculture, water supplies and sea levels. The trouble is, there is virtually no chance that we'll reverse that trajectory. Even the most ambitious proposals for carbon taxes and "cap and trade" emission limits would only slow the rate of increase. And they won't alter the basic fact that, for the foreseeable future, modern economies will still depend overwhelmingly on fossil fuels.

Such realities may sound like defeatism, or apologetics for Big Oil, but should they fill us with despair? It all depends on how you frame the issue. If your starting point is what environmentalists call the "precautionary principle" -- the idea that we must act to avert ecological disaster even when we lack scientific certainty about the extent of the threat -- then our prospects are dim. A radical shift to clean energy, with the aim of ending greenhouse gas emissions, isn't on any government's agenda.

And that may help to explain our peculiar anxieties about the problem. Though we often speak of global warming in terms of crisis, when it comes to policy choices we tend to hedge, as if not quite believing our own rhetoric. One reason for this cognitive dissonance is that distant threats are easy to discount. More fundamentally, I suspect, we are simply not ready to sacrifice the many benefits we derive from our profligate energy habits. As Cass R. Sunstein of the University of Chicago argues in his book "Laws of Fear," a critique of the precautionary principle, a single-minded focus on particular environmental dangers excludes too much. "A better approach," he writes, "would acknowledge that a wide variety of adverse effects may come from inaction, regulation and everything between."

If "precaution" is to make sense, it must be tempered by the logic of cost-benefit analysis, with its trade-offs and estimates of relative risk. Taxing carbon consumption is a fine idea -- it would create incentives for new energy technologies -- but if pushed too far it could depress economic growth. Resources might be better invested in adaptation -- that is, in developing new crops and water supplies for a hotter world. Nor can we let climate change divert attention from more pressing human needs. The social scientist Bjorn Lomborg persuasively argues that the Third World suffers more from malnutrition and H.I.V./AIDS than it is likely to suffer from global warming.

Such a balance sheet will not satisfy those who see the campaign against global warming as an evangelical cause, a way to atone for central air conditioning, S.U.V.'s and other sins against nature. But the current debate would benefit from less emotion and more calculation. Maybe we can still manage to enjoy a perfect 72-degree day, even when it arrives in January.

Gary Rosen is the managing editor of Commentary.