Inquiring Minds

Just when weather weary Americans thought they'd found a reprieve, the latest forecasts suggest that the polar vortex will, again, descent into the heart of the country next week, bringing with it staggering cold. If so, it will be just the latest weather extreme in a winter that has seen so many of them. California has been extremely dry, while the flood-afflicted UK has been extremely wet. Alaska has been extremely hot (as has Sochi), while the snow-pummeled US East Coast has been extremely cold. They're all different, and yet on a deeper level, perhaps, they're all the same.This weather now serves as the backdrop—and perhaps, as the inspiration—for an increasingly epic debate within the field of climate research. You see, one climate researcher, Jennifer Francis of Rutgers University, has advanced an influential theory to explain winters like this. The hypothesis is that by rapidly melting the Arctic, global warming is slowing down the fast-moving river of air far above us known as the jet stream—in turn c