This morning, RealClearPolitics had a piece (“Catching up on global warming”) from The Hill by Mark Mellman of The Mellman Group. Mellman cites public-opinion statistics on global warming to make the case that Congress must act to curb global warming, including the following:

Six in 10 voters also believe global warming results mainly from human activity, compared to just 29 percent who believe global warming is mainly the result of natural causes. . . . a huge 82 percent supermajority are demanding action to reduce U.S. carbon emissions. . . . 11 percent oppose American efforts to reduce carbon emissions.

Mellman writes, “A clear public consensus has emerged on the reality of global warming and the severity of the threat it represents. . . . Voters not only recognize the reality of global warming, but also the serious threat it presents. . . . Americans recognize that carbon pollution is dramatically altering our world for the worse.”

But opinion polls don’t advance science. Opinion polls gauge a selection of society’s thoughts and feelings on a particular topic. They may be useful politically, but they do not establish scientific fact.

Well into the 19th century, bloodletting to release debilitating “humors” was one of the most common and accepted medical procedures, but its broad public acceptance didn’t make it any better for your health.

Science is not about how many people you can persuade to join your cause and adopt your theory. It’s not about a show of hands.

As such, if Congress wants to take action on greenhouse gas emissions, regardless of what the scientific facts are, then Mellman’s polls will come in handy. But if Congress wants to wait on scientific confirmation of the theory of anthropogenic global-warming –a big if, I know — polls such as these simply distract from real progress in the climate debate. Fifty-four percent of Americans know this.