Damn tricky this global warming.
The US is currently experiencing one of the worst periods of cold weather for some time, with temperatures down to -40s, and of course it was only a matter of time before somebody linked it to ‘global warming.’
As we all know, AGW is the unfalsifiable hypothesis to end all unfalsifiable hypotheses. Nothing can disprove it, and any weather phenomenon you care to mention can be regarded as ‘not inconsistent with global warming’.
Bertrand Russell’s teapot, allegedly orbiting in an elliptical orbit somewhere between Earth and Mars isn’t much different – impossible to disprove, and almost as ludicrous as the ‘global warming causes everything’ refrain.
In the words of Karl Popper, what is unfalsifiable is unscientific, and therefore pseudo-science, climate astrology, reading the tea-leaves.
That doesn’t stop Time magazine, however, which reports:
But not only does the cold spell not disprove climate change, it may well be that global warming could be making the occasional bout of extreme cold weather in the U.S. even more likely. Right now much of the U.S. is in the grip of a polar vortex, which is pretty much what it sounds like: a whirlwind of extremely cold, extremely dense air that forms near the poles. Usually the fast winds in the vortex—which can top 100 mph (161 k/h)—keep that cold air locked up in the Arctic. But when the winds weaken, the vortex can begin to wobble like a drunk on his fourth martini, and the Arctic air can escape and spill southward, bringing Arctic weather with it.
What does that have to do with climate change? Sea ice is vanishing from the Arctic thanks to climate change, which leaves behind dark open ocean water, which absorbs more of the heat from the sun than reflective ice. That in turn is helping to cause the Arctic to warm faster than the rest of the planet, almost twice the global average. The jet stream—the belt of fast-flowing, westerly winds that essentially serves as the boundary between cold northern air and warmer southern air—is driven by temperature difference between the northerly latitudes and the tropical ones. Some scientists theorize that as that temperature difference narrows, it may weaken the jet stream, which in turns makes it more likely that cold Arctic air will escape the polar vortex and flow southward. Right now, an unusually large kink in the jet stream has that Arctic air flowing much further south than it usually would.
Just as a cold spell does not disprove climate change, a hot spell does not prove it. Any number of arguments can be advanced to link a particular weather event to global warming, just as the same number of different arguments could be applied to link such an event to something else, like the Green Climate Monster, who I personally blame for all occurrences of extreme weather: