“We need more than the same old empty promises,” President Obama declared on Monday. He therefore offered new empty promises, most conspicuously a vow to create “a new energy economy that puts millions of our citizens to work.”

As he did during his campaign, Obama presented his plan to ameliorate global warming as a way of stimulating the economy, with the first steps – money for weatherizing buildings, boosting alternative energy production and improving power transmission – incorporated into his American Recovery and Reinvestment Plan. Thus he continues to ignore the enormous cost of dramatically reducing carbon dioxide emissions, falsely portraying the economic burden as a boon.

Obama still officially intends to “help create five million new jobs by strategically investing $150 billion over the next 10 years to catalyze private efforts to build a clean energy future.” Exactly where that projection comes from is a mystery.

The Apollo Group, a coalition of environmentalists and labor unions that has influenced the president’s thinking in this area, also talks about creating 5 million “green-collar jobs” during the next decade, although it puts the cost to taxpayers at $500 billion, more than three times Obama’s figure. But maybe we should not get too hung up on this estimate or the basis for it.

“Honestly,” the Apollo Alliance’s co-director told The Wall Street Journal right after the election, “it’s just to inspire people.” In that case, why not say 10 million jobs over five years, or 20 million over two?

It’s not as if anyone will ever be held to account for these wild promises. Since there’s no agreement about what constitutes a “green-collar job,” who’s to say whether the goal has been met?

Given the malleability of the concept and the fancifulness of the numbers, politicians’ faith in Obama’s green snake oil is touching. “For us to support what needs to be done in addressing global warming,” Sen. Debbie Stabenow, D-Mich., recently told The New York Times, “we need to demonstrate that, in fact, jobs are created.”

Stabenow, whose state is heavily dependent on coal, is rightly concerned about the economic impact of Obama’s cap-and-trade plan for reducing carbon dioxide emissions, which will sharply increase the cost of fossil-fuel energy. But she is mistaken if she thinks that “green jobs” can compensate for the economic pain that plan must inflict in order to work.

To see the fallacy here, consider this: If Obama could snap his fingers and make global warming disappear tomorrow, should he do it? By his logic, no, because then we’d lose all those wonderful green jobs that will help pull us out of the recession.

The justification for a cap-and-trade system (or a carbon tax, which likewise aims to shift the economy away from fossil fuels by making them more expensive) lies not in the jobs it will “create,” which will be more than balanced by the jobs it will destroy or forestall, but in the bad consequences it will prevent. Obama alluded to those in his speech, saying, “the long-term threat of climate change … could result in violent conflict, terrible storms, shrinking coastlines and irreversible catastrophe.”

To know whether Obama’s cap-and-trade proposal makes sense, we need to know how likely those outcomes are and how costly they would be. We also need to know how likely it is that his plan actually would prevent the dire results of which he warns and, crucially, at what cost.

Critics such as Bjorn Lomborg, author of “Cool It: The Skeptical Environmentalist’s Guide to Global Warming,” argue that adapting to climate change is much more cost-effective than trying to prevent it, an effort they say is unlikely to have any measurable impact. Presumably Obama thinks these skeptics are wrong. I’d like to hear why.

But that would require the president to be more candid about the sacrifices demanded by his plan to create “the new energy economy.” It is difficult to perform a cost-benefit analysis if you refuse to admit there’s a cost.

COPYRIGHT 2008 CREATORS SYNDICATE, INC.