It is a reliable occurrence now: every time we have a cold event here in the United States, two public conversations begin, both of which deploy the term “polar vortex.” Those who are suspicious of the reality of climate change and persist in calling it “global warming” argue that these polar vortex-driven cold events are evidence the warming is fake news. Other people know polar sea ice is vanishing while these polar vortex events seem to be multiplying and amplifying. The climate, people say, is just getting out of control. But new developments in climate research are steadily making more sense of the changes we are witnessing.