You may have heard a climate change skeptic point to a cold snap as proof that the planet isn't actually warming. Proponents, however, note that climate change may actually be contributing to distortions of the polar vortices, and the sudden plunges in temperature that those distortions cause.
Here's the possible explanation. Scientists have observed that more and more Arctic sea ice is melting during the summer months. As the ice melts, the Arctic Ocean warms, and radiates that excess heat back to the atmosphere in winter. Because that heat somewhat reduces the contrast between the Arctic air and the atmosphere in regions farther south, it reduces the intensity of the winds that form the barrier between the two areas. That, in turn, weakens and disrupts the polar vortex. That hypothesis is supported by data taken over the past decade, which shows that in years when a lot of Arctic sea ice disappears, the vortex has a greater tendency to weaken [source: Fischetti].
Not everyone, it should be mentioned, embraces the notion that Arctic sea ice changes influence weather patterns elsewhere [source: Samenow]. But if it is true, the particularly scary part of that model is that while the amount of Arctic sea ice varies from year to year, overall it's been decreasing in recent years, and climate scientists' forecasts call for it to vanish even more. That could mean that we may experience more distortions of the polar vortex, and the extreme weather that accompanies them, in years to come [source: Fischetti].