In January of 2014, a displaced polar vortex brought extremely cold temperatures to many parts of the U.S., causing Lake Michigan near Chicago to freeze over, as shown in this post from Forbes. The current cold snap is extremely similar in nature, and is wreaking havoc across much of the continental U.S. right now. The country is freezing in an unprecedented fashion, and global warming is to blame. The cold snap that North America is experiencing east of the rocky mountains, with temperatures at Arctic-like levels, is real, but it's only part of the story. Simultaneously, there are record warm temperatures happening in other parts of the world, from Australia to the actual Arctic. While a small but vocal minority of people might use the faulty logic of, "it's cold where I am, therefore global warming isn't real," even schoolchildren know that weather isn't climate. But these extreme cold snaps have gotten more severe in recent years, due to a combination of global warming and a phenomenon you've likely heard of: the polar vortex. Here's the science  of how it works, and why global warming is paradoxically playing a major role in today's record-low temperatures.