Abnormal is the New Normal: Shifting Baselines, Polar Vortices, and Climate Change
The Polar Vortex, a mass of cold air usually centered around points within the Arctic Circle, made a visit south for the second time in 2014. The Vortex brings freezing weather, snow, and ice to regions that are unaccustomed to such extreme conditions. It also brings with it a new spate of “so much for global warming” talking-points, fresh on the heals of a recent report revealing that Climate Change Denial is at an all time high.
Unfortunately for the climate change denial industry, Polar Vortices are well-understood atmospheric phenomena. They were documented as early as 1853 as currents of cold air that essentially circle the poles. High-altitude observations in the 1950’s revealed the occurrence of sudden stratospheric warming (SSW) in the Arctic Polar Vortex. These SSW’s can cause a the vortex to weaken or reverse directions, allowing it to drift off axis or split into several smaller vortices. When weakened vortices contact the jet stream, cold arctic air is forced south, resulting in anomalously cold temperatures.
The obvious next question is: Is the weakened polar vortex caused by climate change?