A number of years ago, I was discussing rent control with someone who had managed to snag a government-subsidized co-op. "But you have to understand," he said earnestly, in response to my eminently reasonable economic arguments, "If it weren't for rent control, someone like me couldn't afford to live in Manhattan."

My response, though I never said it out loud, was a puzzled "So what?" Living in Manhattan is not a civil right. It's ludicrous to think that we should construct an elaborate regulatory system that degrades the housing stock and helps push the vacancy rate down to 2%, all so that averagely paid government workers can afford a two bedroom apartment near Lincoln Center. If you want to live in Manhattan, you should prepare yourself for a job that will pay you enough to do so. Or you can do what I did, and cram yourself into 400 square feet of cave-like space on the first floor of a building where the hot water supply ranges from temperamental to nonexistent. But the idea that the government has a duty to reallocate the very limited supply of attractively located Manhattan apartments to . . . well, to the kind of people who know the guy who allocates the supply of attractively located Manhattan apartments . . . seems so transparently awful that I was struck dumb.

My conservative readers are no doubt nodding along in glee. But here's the thing: how come so many of you are complaining that, in the event of a heavy carbon tax, it would suddenly become less affordable to live in Kansas, or the suburbs?

I don't see it as the government's job to enable you to live in Kansas, or a big house on a half-acre lot in the leafy suburbs, any more than it is the government's job to enable you to live on 67th & Broadway. The fact that these things are very desirable, even desirable to a majority of the country, doesn't mean that the government should be in the business of subsidizing your desires through things like road construction. The majority of the country would probably also like a Manhattan apartment with a river view for $500 a month.

I don't have any objection to your getting those things either; I don't have the urban snob's feeling of moral superiority to people who have chosen grass and trees over pavement and nightlife. I too, enjoy sitting in the yard on a sunny day watching the children run hither and yon; it doesn't surprise me that many people have voted with their feet.

However, if getting you that big house in the leafy suburbs requires imposing heavy costs on other people--either directly through taxes, or indirectly through negative externalities--then no, I do not think you should have that house, no matter how much you like it. And right now, people who live in those houses are dumping a whole lot more carbon into the air than people who live in denser housing. The heat loss on a large detached house means you waste a lot more carbon keeping it warm in the winter, and cool in the summer, particularly if you buy coal-fired electricity. The greater distance between you and your electric power source means greater transmission losses. And, of course, you have to drive everywhere, since your house is clustered too loosely to make public transit effective. Transportation accounts for about 35% of US carbon emissions, and 2/3 of that comes from cars and light trucks. The warming from that carbon seems to pose an unacceptably high risk of fouling up the only climate we have.

To the people who said "But I thought you were a libertarian!", this sort of negative externality is exactly what a libertarian government is supposed to deal with. If your activity imposes heavy costs on your neighbors, and there's no possibility of a Coasean bargain, then the commons and free rider problems pose a pretty clear argument for government intervention. Just as it is clearly within the scope of government action to prevent a factory from dumping cyanide into the water table, it seems well within the scope of libertarian theory to say that individuals should not be permitted to poison a commons for which we have so far been unable to establish property rights. As far as I'm concerned, the open questions are: what is the extent of the likely damage, how much should we do to prevent unlikely but catastrophic scenarios, and what are the utilitarian costs to the future of reducing carbon output now. The open questions are not: is anthropogenic global warming occurring; or, is it morally all right to emit huge amounts of carbon that might destroy the planet?

Mind you, I also find the environmental movement sadly lacking here. Any question as to the physical or political feasibility of catering to the most extreme scenarios, much less the actual desirability of doing so, is too often met with accusations that you are a selfish bastard who hates the planet. Any suggestion that there may be no easy and cost-effective way to reduce emissions earns anger and an exasperated "Well, what do you plan to do about it?" as if to state a problem were also to imply that there must be a solution. And a shocking number of fellow travelers on the left do so little to reduce their own carbon emissions that it might as well be nothing, on the grounds that it's irrelevant until we get collective action--and then denounce me for pointing out that exactly the same logic applies to leaving China and India out of any global emissions trading regime. And almost any environmentalist living in an urban area is all too willing to use their environmental beliefs for a fine bit of class warfare, demanding that we truncheon suburbanites and red-staters into dense urban housing. Frankly, there are few public debates so thoroughly dominated by emotion--and not particularly lovely emotion--masquerading as logic.

I don't care how we reduce emissions. If nuclear power and hybrid vehicles can maintain the lifestyles of suburbanites and Kansans, I will be perfectly happy. The moral question is whether or not you reduce the carbon output, not how you achieve the reductions. And since it seems obvious to me that politically, most of the country will not go along unless you can find a solution that does not involve forcing them all to move to San Francisco, environmentalists would do better to focus on alternatives that conservatives might, at least grudgingly, come to like.

Obviously, since I already live a fairly low carbon lifestyle, I am vulnerable to charges that I favor things that hurt others more than myself. But I don't think I'm particularly vulnerable to charges of hypocrisy. When I was broke, sick, and uninsured, I didn't suddenly discover that I favored national health insurance; and when I moved to DC, I first looked for a tiny fuel efficient car, and then decided to forgo having one altogether, even though it's rather hard to get around here without one.

The whole point of a moral code, after all, is that sometimes it makes you do things you'd rather not.

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