What’s to Blame for the Polar Vortex?

As freezing temperatures break records and make headlines across the country, some wonder what’s behind the so-called polar vortex responsible for the frigid dips. The severe drop in temperature may not come as a complete surprise for many Americans, as 63 percent of people say the weather has been getting more extreme during the past few years, while six percent say it’s gotten less extreme and about 3-in-10 (29 percent) say it hasn’t changed.