Connecticut, Maine, Maryland, Massachusetts, Rhode Island and Vermont took part in America’s first auction of carbon credits the other week. The auction raised $38.5 million that the states can divvy up for renewable-energy or conservation programs. (Rhode Island would get $1.3 million.) Making power plants buy “allowances” or “carbon credits” for the carbon dioxide they emit should help slow the increase in CO{-2} emissions.

But not nearly as much as the much simpler and more effective technique of imposing new taxes on fossil-fuel use — for power plants, gasoline users and so on — and using the funds to develop alternative energy and to implement conservation programs.

But of course, that would be politically difficult. Carbon-credit sales give the impression that we are doing something green by using the “magic of the marketplace” while having an insignificant effect on the energy crisis, at least as the carbon-trading system is now constituted in America.