Paul M. Barrett writes: Yes, yes, it’s unsophisticated to blame any given storm on climate change. Men and women in white lab coats tell us — and they’re right — that many factors contribute to each severe weather episode. Climate deniers exploit scientific complexity to avoid any discussion at all.

Clarity, however, is not beyond reach. Hurricane Sandy demands it: At least 40 U.S. deaths. Economic losses expected to climb as high as $50 billion. Eight million homes without power. Hundreds of thousands of people evacuated. More than 15,000 flights grounded. Factories, stores, and hospitals shut. Lower Manhattan dark, silent, and underwater.

An unscientific survey of the social networking literature on Sandy reveals an illuminating tweet (you read that correctly) from Jonathan Foley, director of the Institute on the Environment at the University of Minnesota. On Oct. 29, Foley thumbed thusly: “Would this kind of storm happen without climate change? Yes. Fueled by many factors. Is storm stronger because of climate change? Yes.” Eric Pooley, senior vice president of the Environmental Defense Fund (and former deputy editor of Bloomberg Businessweek), offers a baseball analogy: “We can’t say that steroids caused any one home run by Barry Bonds, but steroids sure helped him hit more and hit them farther. Now we have weather on steroids.”

In an Oct. 30 blog post, Mark Fischetti of Scientific American took a spin through Ph.D.-land and found more and more credentialed experts willing to shrug off the climate caveats. The broadening consensus: “Climate change amps up other basic factors that contribute to big storms. For example, the oceans have warmed, providing more energy for storms. And the Earth’s atmosphere has warmed, so it retains more moisture, which is drawn into storms and is then dumped on us.” Even those of us who are science-phobic can get the gist of that.

Sandy featured a scary extra twist implicating climate change. An Atlantic hurricane moving up the East Coast crashed into cold air dipping south from Canada. The collision supercharged the storm’s energy level and extended its geographical reach. Pushing that cold air south was an atmospheric pattern, known as a blocking high, above the Arctic Ocean. Climate scientists Charles Greene and Bruce Monger of Cornell University, writing earlier this year in Oceanography, provided evidence that Arctic icemelts linked to global warming contribute to the very atmospheric pattern that sent the frigid burst down across Canada and the eastern U.S..