We knew this was coming eventually. It came from Bryan Walsh, writing in Time:
As the blizzard-bound residents of the mid-Atlantic region get ready to dig themselves out of the third major storm of the season, they may stop to wonder two things: Why haven’t we bothered to invest in a snow blower, and what happened to climate change?
…There is some evidence that climate change could in fact make such massive snowstorms more common, even as the world continues to warm. … That’s in part because of global warming — hotter air can hold more moisture, so when a storm gathers it can unleash massive amounts of snow.
The real problem is not that this explanation is wrong — in fact, the “more-moisture-there, more-snow-here” theory is actually somewhat plausible. Of course, in the next sentence Walsh points out the opposite:
Colder air, by contrast, is drier; if we were in a truly vicious cold snap, like the one that occurred over much of the East Coast during parts of January, we would be unlikely to see heavy snowfall.
The real problem is with both claims taken together: last year’s relative lack of snow was cited as proof of global warming, and this year’s over-abundance of snow is also cited as proof of global warming. A theory that is considered confirmed by whatever happens, no matter what happens, is not a scientific theory at all. It’s like Petr Beckmann’s example of an “inherently irrefutable” claim, which is that there is a second moon orbiting the earth which has zero mass and becomes transparent when illuminated. That theory is entirely consistent with such an object never being observed — which means it can never be disproved no matter how false it is.
So it is with global warming. If there is lower-than-average snow it’s due to global warming (“too warm for snow to form”) and if there is higher-than-average snow it’s due to global warming (“more moisture there, more snow here”), and if snowfall is average, the two cancel out. If northern Europe as a less severe winter, it’s due to global warming making winters less cold; if northern Europe as a more severe winter, it’s due to global warming interfering with the Gulf Stream.
No matter what happens, it’s “proof” of global warming. It’s the theory that can never be disproved no matter how false it is. Which is to say, it’s not really a scientific theory at all.