That's a politically impossible price tag, especially for nothing more than a theory that higher temperatures might do more harm than good.

Contrary to what most global warming zealots claim, costs are not irrelevant -- not when limited resources could be used to immediately benefit humanity in ways with much more scientific certainty. And not when scientists admit that dismantling entire economies would bring little benefit in the realm of climate change.

Papers recently published in the journals Geophysical Research Letters and Global Biogeochemical Cycles claim the world would have to stop emitting carbon altogether within a few decades to rein in rising temperatures. That's not a misprint -- no carbon emissions anywhere before the middle of this century. Note to the world's jet-setting celebrity environmentalists: Such a mandate would ground airplanes.

"In the end, this is a value judgment, it's not a scientific question," University of Washington philosophy professor Steve Gardiner, who studies climate change, told The Washington Post. Creating a carbon-free society "appears to be technically feasible. The question of whether it's politically feasible or economically feasible is a separate question."

Yet most of the world's political elites continue to pitch expensive benchmarks that, according to this research, will do nothing. A U.S. Senate proposal seeks to reduce American emissions by 70 percent within 40 years. Democratic presidential candidates Hillary Clinton and Barack Obama want an 80 percent cut by 2050; Republican John McCain wants a 60 percent reduction. The U.N. Intergovernmental Panel on Climate Change wants the First World to cut emissions by between 80 and 95 percent, while allowances for China, India and other developing nations would tolerate a global emissions cut of no less than 50 percent by 2050.

Are the greens demanding that 3,000 nuclear power plants be built around the world within 20 years to meet their ambitious goals? No, they're demanding global reliance on solar, wind and geothermal power, technologies that, by themselves, can't come close to meeting the world's energy needs.

Meanwhile, the movement to get governments to tackle calamities that have cost-effective solutions isn't gaining much traction. Danish political scientist and author Bjorn Lomborg has pointed out that for a fraction of the money Al Gore wants to spend eliminating carbon emissions, the world could save hundreds of millions of lives over the next century eradicating malaria and HIV/AIDS; providing the entire world with a reliable, clean supply of potable water; and eliminating malnutrition through the free trade of agricultural products.

That radical environmentalists oppose allowing Earth's human population to continue to grow says a lot about their agenda here.

In the long run, selling the public on panic won't do anyone any good. Alarmists are going to have to pitch realistic solutions, with realistic costs, as well.