"Instead of idly debating the precise extent of global warming, ... we need to deal with the central facts of rising temperatures, rising waters, and all the endless troubles that global warming will bring. We stand warned by serious and credible scientists across the world that time is short and the dangers are great. The most relevant question now is whether our own government is equal to the challenge" (http://tinyurl.com/6rt5s9).

With that, the presumptive Republican presidential nominee John McCain threw his support -- again -- to a complex government program to reduce carbon emissions. He claims he can do this, without causing economic hardship, by using the power of the free market.

As The Wall Street Journal commented, "His plan is 'market based' insofar as it requires an expensive, invasive government bureaucracy to interfere with the market".

McCain's cap-and-trade system would have a bureaucracy set a limit for CO2 emissions and auction tradable permits to carbon-emitting companies. McCain says the revenue would be "put to good use." Specifically, "We will add to current federal efforts to develop promising technologies. ... We will also establish clear standards in government-funded research, to make sure that funding is effective and focused on the right goals."

We've heard that before. You'd think McCain would have learned that government isn't cut out for this sort of thing.

For all his lip service to markets, there is no getting around the fact that McCain will use force -- that's what government is -- to accomplish his goals. There are only two ways to do things: voluntary or forced. The market is voluntary. No one is ever forced to buy or sell anything.

Cap-and-trade sounds good. Trade is good. But "cap" is force. Government will make arbitrary decisions about how much CO2 will be permitted in a thousand different situations. I can only begin to imagine the bureaucracy that will be required. Will chimney police go to every business and home telling you how much you can emit? Will armed officials from a Department of Global Warming raid your house and jail you if you run your air-conditioner too much? I assume friends of Al Gore will get special dispensation because they are working for the good of the nation.

How much will McCain's plan reduce global temperatures?

He doesn't say -- probably because even the most radical climate-change policies promise no more than a negligible reduction.

As Fred S. Singer, president of the Science & Environmental Policy Project, told the Heartland Institute in 2007, "All these schemes are quite ineffective in reducing the global growth of atmospheric CO2 -- never mind in having any effect on climate. The schemes do have one thing in common: They will damage the U.S. economy and hurt the pocketbooks of every consumer..."

In other words, economic growth will be stifled -- for what?

Roy W. Spencer, a research scientist at the University of Alabama in Huntsville and author of "Climate Confusion," says he's "increasingly convinced" that climate change has far more to do with natural phenomena like El Nio and the Pacific Decadal Oscillation than carbon dioxide. "Maybe the amount of CO2 in the atmosphere is higher now than it has been in hundreds of thousands of years. So what?" he wrote in a recent article for the National Review.

"Even though there has never been a single scientific paper published that has ruled out natural variability for most of the warming we've seen since 1850, Big Science has managed to convince politicians and much of the public that the science is settled. Apparently, our addition of nine molecules of carbon dioxide to each 100,000 molecules of air over the last 150 years can now be blamed for anything and everything ... Hurricanes, tornadoes, heat waves, floods, glaciers flowing toward the sea ... these used to happen naturally, but no more".

Spencer is one of many scientists who doubt the "consensus" that CO2 will cause a global warming "crisis." But politicians still want to act.McCain's hero is Teddy Roosevelt, a hectoring, activist president. To justify government interference in our lives, it helps to have a crisis. In Islamic extremism, McCain has his foreign affairs crisis. In global warming, he has his domestic crisis.