For example, in Phase I of the European Union's Emissions Trading Scheme, which started three years ago, a huge misallocation of emissions quotas led to a collapse in the price of carbon from $40 to 40 cents. At that price, there was no incentive to reduce emissions, which is why Phase I was an abject failure.

Even a functioning cap could have only a limited effect on emissions. Energy-intensive industries would have every incentive to move their operations to countries without carbon controls, like China. As a result, McCain's plan would cause a net reduction not of greenhouse gas emissions, but of American jobs.

The Arizona senator's plan might not shrink emissions, but it will surely grow government.
(and raise billions of dollars)

McCain does not offset this increase in government revenue with tax cuts elsewhere in the budget, so government would get bigger. He has said that he wants to promote "green jobs," and indeed he would be doing so, by adding green bureaucrats.

Congress is considering several climate bills, all of which include cap and trade schemes along the lines of McCain's American jobs killing proposal. If the Arizona senator wants to be a true maverick, he should buck the trend that he helped start -- by supporting free market solutions to global warming that might actually make a difference.