Under such a tax, the prices of goods would rise in proportion to their carbon footprints  in the case of gasoline, for example, by roughly $2.60 a gallon.

Image Credit... David G. Klein

A sudden price increase of that magnitude could indeed be painful. But if phased in, it would cause much less harm. Facing steadily increasing fuel prices, for example, manufacturers would scramble to develop more efficient vehicles.

Even from the existing menu of vehicles, a family could trade in its Ford Explorer, getting 15 miles per gallon, for a 32-m.p.g. Ford Focus wagon, thereby escaping the effect of higher gasoline prices. Europeans, many of whom already pay $4 a gallon more than Americans do for gasoline, have adapted to their higher prices with little difficulty.

In short, the cost of preventing catastrophic climate change is astonishingly small, and it involves just a few simple changes in behavior.

The real problem with the estimates is that the outcome may be worse than expected. And that’s the strongest possible argument for taking action. In a rational world, that should be an easy choice, but in this case we appear to be headed in the wrong direction.

This strange state of affairs may be rooted in human psychology. As the Harvard psychologist Daniel Gilbert put it in a 2006 op-ed article in The Los Angeles Times, “Global warming is bad, but it doesn’t make us feel nauseated or angry or disgraced, and thus we don’t feel compelled to rail against it as we do against other momentous threats to our species, such as flag burning.”

People tend to have strong emotions about topics like food and sex, and to create their own moral rules around these emotions, he says. “Moral emotions are the brain’s call to action,” he wrote. “If climate change were caused by gay sex, or by the practice of eating kittens, millions of protesters would be massing in the streets.”