Sen. John McCain made a climate speech Monday in which he argued that doing something about climate change is a “test of foresight, of political courage, and of the unselfish concern that one generation owes to the next.”

His timing is curious. “Ignore that man behind the curtain,” his speech seemed to be saying. “You know, the man who is beating up on Sen. Barack Obama for refusing to support his gas-tax holiday proposal; the one who will be making it easier for Americans to consume greater amounts of carbon-rich fossil fuel.”

Of course, it is hard to ignore the man behind the curtain.

Both McCain and Sen. Hillary Clinton have supported proposals to slow greenhouse-gas emissions. Both are centered on cap-and-trade initiatives that would cap the amount of carbon the U.S. could consume and force the purchase of carbon permits by those industries in the business of releasing carbon into the atmosphere. This is the premise behind the Lieberman-Warner bill now under active consideration by the Senate, which McCain can rightly claim contains his policy DNA, as he sponsored the earlier McCain-Lieberman bill based on the same cap-and-trade principle. (There is hardly a climate scientist out there who thinks Lieberman-Warner comes close to doing what’s necessary to address climate change, but that’s another story.)

In her campaign climate and energy proposal, Clinton said she would go further than Lieberman-Warner, which would hand over billions of dollars of carbon credits to historic polluters. Clinton would require that a full 100 percent of carbon permits be auctioned in the marketplace. This position makes good policy sense because industries most responsible for the growing climate disaster should not financially benefit at the expense of energy consumers. Under Clinton’s 100 percent auction approach, historic polluters would have to bid to purchase the number of carbon credits they need along with all other industries and individuals who think they could make a buck buying and selling such credits.

The details vary, but the premise of both senators’ plans is that fuels with more significant carbon content, like coal-generated electricity and gasoline, should — are you ready, senators? — cost more.

Raising the cost to industry and ultimately to consumers of carbon-intensive energy would provide a financial incentive to develop more renewable fuels and provide a financial advantage to those industries and individuals who use energy more efficiently. Creating a market signal, in fact, is the whole point behind the cap-and-trade proposals that McCain and Clinton support.

But who cares about consistency and looming global disaster when there are political points to score? So, faster than you can say “melting glaciers,” first McCain followed by Clinton tout a gas-tax holiday plan that runs in the opposite direction of their climate plans. Suddenly I have more confidence in the Wizard getting Dorothy back to Kansas then I do in the senators standing firm when the going gets tough addressing climate change.

The world scientific community is more unified than ever that the “business as usual” scenario threatens all living things on earth. NASA climatologist James Hansen’s most recent research concludes that the current level of atmospheric CO2 is too high and must be reduced to 350 parts per million to avoid the most disastrous consequences of climate change — notably the melting of Greenland’s ice sheet and inundation of coastal communities, including those in the United States.

The news is not all dire. There are also a myriad of economic opportunities for companies — and for the nation — quickest to innovate and adopt technologies that lead to less-polluting and more-efficient sources of energy. General Electric and Dow Chemical understand this. Moving aggressively to make the United States that nation is a promise the American public could rally around.

Other climate proposals offered, such as “cap and dividend,” would economically benefit low-income families. Under the cap-and-dividend approach, revenues raised by auctioning carbon credits would be rebated back to each citizen, à la Alaska’s permanent oil fund. These “carbon dividends” would shield lower-income families from rising energy costs, or help them come out ahead if they move to a higher mileage car or save on their home heating and cooling costs.

But the prospect of economic and environmental renewal that McCain attempted to convey on Monday is dwarfed by his and Clinton’s now-dominant environmental message: We may be addicted to the cheap rotgut of carbon-based fuel, but not to worry; your government will do its best to lower the cost of the blackberry brandy so we can party on.

This presidential campaign has been nearly devoid of serious climate debate, so McCain’s speech on Monday was welcome. But his gas-tax proposal sent a wildly different message that can’t be reconciled with “straight talk” or with the leadership necessary to tackle to the foremost issue of our time.

(The views expressed here are those of the writer only.)