In January 2014, the eastern and southern United States were plunged into extraordinarily frigid temperatures that stranded air travelers, stressed power grids, closed schools, and killed more than 20 people. In all, the lives of more than 187 million people (roughly 60% of Americans) were affected by the record-breaking cold. Meteorologists identified the “polar vortex” as the culprit: a large cyclone, first studied in 1853, which gyres around the North Pole. Much to these scientists’ dismay, they then watched their explanation become yet another flashpoint in the rhetorical war over climate change.