WASHINGTON – Unfortunately, China’s president had to dash home to suppress ethnic riots. Had he stayed in Italy at the recent G-8 summit, he could have continued the Herculean task of disabusing Barack Obama of his amazingly durable belief, shared by the U.S. Congress, that China – and India, Brazil, Mexico and other developing nations – will sacrifice their modernization on the altar of climate change. China has a more pressing agenda, and not even suppressing riots tops the list.

China made this clear in June, when its vice premier said, opaquely, that China will “actively” participate in climate change talks on a basis of “common but differentiated responsibility.” The meaning of that was made clear three days later, at a climate change conference in Bonn, where a Chinese spokesman reiterated that his country’s priority is economic growth: “Given that, it is natural for China to have some increase in its emissions, so it is not possible for China in that context to accept a binding or compulsory target.” That was redundant: In January, China announced that its continuing reliance on coal as its primary source of energy will require increasing coal production 30 percent in the next six years.

In Bonn, even thoroughly developed Japan promised only a 2 percent increase of its emission-reduction obligations under the 1997 Kyoto agreement. Japan’s decision left Yvo de Boer, the slow learner who is the U.N.‘s climate change czar, nonplussed: “For the first time in my two and a half years in this job, I don’t know what to say.”

Others did. They said: On to Italy! The Financial Times reported, “Officials are now pinning their hopes” on the G-8 summit.

Which has come and gone, the eight having vowed to cut emissions of greenhouse gases 80 percent by 2050, which is 41 years distant. As is 1968, which seems as remote as the Punic Wars, considering that more than half of all living Americans were born after 1966. If you do not want to do anything today, promise to do everything tomorrow, which is always a day away.

Still, sternly declaring that they will brook no nonsense from nature, the eight made a commitment – but a nonbinding one – that Earth’s temperature shall not rise by more than 3.6 degrees Fahrenheit over “preindustrial levels.” That is the goal. Details to follow. Tomorrow.

Explaining such lethargy in the face of a supposed emergency, the G-8’s host, Italy’s Prime Minister Silvio Berlusconi, said the eight should not burden themselves as long as “5 billion people continue to behave as they have always behaved.” Actually, the problem, for people who think it is a problem, is that the 5 billion in the developing world are behaving in a new way. After centuries of exclusion from economic growth, they are enjoying it, which is tiresome to would-be climate fixers in already prosperous nations.

The fixers say: On to Copenhagen! There, in December, the moveable feast of climate confabulations will continue. By which time China alone, at its current pace, probably will have brought on line 14 more coal-fired generating plants, each of them capable of providing all the electricity needed for a city the size of San Diego. And last Sunday, India told visiting Secretary of State Hillary Clinton that there is “no case” for U.S. pressure on India to reduce carbon emissions.

The costs of weaning the U.S. economy off much of its reliance on carbon are uncertain, but certainly large. The climatic benefits of doing so are uncertain but, given the behavior of those pesky 5 billion, almost certainly small, perhaps minuscule, even immeasurable. Fortunately, skepticism about the evidence that supposedly supports current alarmism about climate change is growing, as is evidence that, whatever the truth about the problem turns out to be, U.S. actions cannot be significantly ameliorative.

When New York Times columnist Tom Friedman called upon “young Americans” to “get a million people on the Washington Mall calling for a price on carbon,” another columnist, Mark Steyn, responded: “If you’re 29, there has been no global warming for your entire adult life. If you’re graduating high school, there has been no global warming since you entered first grade.”

Which could explain why the Mall does not reverberate with youthful clamors about carbon. And why, regarding climate change, the U.S. government, rushing to impose unilateral cap-and-trade burdens on the sagging U.S. economy, looks increasingly like someone who bought a closetful of platform shoes and bell-bottom slacks just as disco was dying.

© 2009, Washington Post Writers Group