Bernie Sanders has twice called climate change the United States’ “biggest threat to national security.” The first time was during the inaugural Democratic debate on October 13. The second was in its comparatively little-watched sequel, which aired hours after eight ISIS-affiliated European nationals sporting bomb-equipped vests opened fire on diners, sports enthusiasts, and Eagles of Death Metal fans around Paris.

“Climate change is directly related to the growth of terrorism,” Sanders bellowed in response to CBS moderator John Dickerson’s question. “And if we do not get our act together and listen to what the scientists say, you’re going to see countries all over the world . . . struggling over limited amounts of water [and] land to grow their crops, [and] you’re going to see all kinds of international conflict.”

By the time the onslaught on the French capital was over, it had claimed at least 129 lives and injured hundreds more. This week, the city will host the twenty-first annual conference of parties, or COP21, gathering world leaders and civil society groups to figure out how to curb carbon emissions and, ideally, rising temperatures.