Parts of North America have recently been affected by a polar vortex. A polar vortex is an extremely cold wave of air that is deadly and can cause frostbite in minutes. In the midwest, there were temperatures as low as -50ºF (-45.5ºC), not including the windchill.
President Donald Trump tweeted on January 28, "In the beautiful Midwest, windchill temperatures are reaching minus 60 degrees, the coldest ever recorded. In coming days, expected to get even colder. People can’t last outside even for minutes. What the hell is going on with Global Waming [sic]? Please come back fast, we need you!"
However, scientist Jennifer Francis was on of the first to link the polar vortex to climate change. As the ocean warms, it releases more heat. “Because of that extra heat that has come out of the ocean, it can generate extra wave energy in the jet stream,” she said. “In the winter time, that wave energy can transfer upwards into the stratosphere, and if enough of it gets transferred and it goes on for a long enough time, it can actually have this effect on the polar vortex," which normally resides 30 miles above the Arctic Circle.