Victor Davis Hanson

But even without the corruption and hypocrisy, sincere advocates of man-made global warming themselves overreached. At news that the planet had not heated up at all during the last 10 years, "global warming" gave way to "climate change" -- as if to warn the public that unseasonable cold or wet weather was just as man-caused as were the old specters of drought and scorching temperatures.

Then, when "climate change" was not still enough to frighten the public into action, yet a third term followed: "climate chaos." Suddenly some "green experts" claimed that even more terrifying disasters -- from periodic hurricanes and tornadoes to volcanoes and earthquakes -- could for the first time be attributed to the burning of fossil fuels. At that point, serially changing the name of the problem suggested to many that there might not be such a problem after all.

Current hard times also explain the demise of global warming advocacy. With high unemployment and near nonexistent economic growth, Americans do not want to shut down generating plants or pay new surcharges on their power bills. Most people worry first about having any car that runs -- not whether it's a more expensive green hybrid model.

Over the last half-century, Americans have agreed that smoky plants and polluting industries needed to be cleaned up. But when the green movement began to classify clean-burning heat as a pollutant, it began to lose the cash-strapped public.

While the Obama administration was subsidizing failed or inefficient green industries, radical breakthroughs in domestic fossil-fuel exploration and recovery -- especially horizontal drilling and fracking -- have vastly increased the known American reserves of gas and oil. Modern efficient engines have meant that both can be consumed with little, if any, pollution -- at a time when a struggling U.S. economy is paying nearly half a trillion dollars for imported fossil fuels. The public apparently would prefer developing more of our own gas, oil, shale, tar sands and coal as an alternative to going broke by either importing more fuels from abroad or subsidizing more inefficient windmills and solar panels at home.

We simply don't know positively whether recent human activity has caused the planet to warm up to dangerous levels. But we do know that those who insist it does are sometimes disingenuous, often profit-minded, and nearly always impractical.

Victor Davis Hanson

Victor Davis Hanson is a classicist and historian at the Hoover Institution, Stanford University, and a recipient of the 2007 National Humanities Medal.