In the New York Times, Robert Frank discusses the gas tax: "A Way to Cut Fuel Consumption That Everyone Likes, Except the Politicians." Indeed, it's not clear why a $2-a-gallon gas taxwhich would then be refunded to Americans through reduced payroll taxesis so politically unviable, except that it was unpopular when Jimmy Carter first proposed it, and has been stuck with a bad reputation ever since. But here's the bottom line: "In the warmer weather they will have inherited from us a century from now, perspiring historians will struggle to explain why this proposal was once considered politically unthinkable." Right, exactly.
Now there are some decent arguments that a gas tax would have an unfair impact on certain people in the United States: it would fall especially heavily on those who live in rural areas and can't easily adjust their driving habits. Perhaps regional tax credits of sorts could help those who are being disproportionately hurt, but yes, there will be quite a bit of pain. Moreover, there's some evidence that stricter CAFÉ standards on automakers could increase fuel efficiency more gently than gas taxes would (although drivers might just respond by driving more, and total fuel consumption wouldn't go down).
Still, the main point here is that reducing fuel consumption in the U.S. and somehow averting global warming is going to be a massive and radical undertakingperhaps a near-impossible one. The idea that we can somehow achieve this by doing stuff that doesn't inflict any pain whatsoever is an unrealistic one.