This is what happens when science is hijacked in pursuit of ideologically driven economic policies. If the Paris Agreement is substantively a joke, then the widespread rage about President’s Trump’s withdrawal is, as many people have already noted, surely a case of mass virtue signaling. But the episode does reflect a larger problem for the Left. Whenever the United States fails to adopt climate-change policy favored by the Left, advocates like to point to polls that allegedly illustrate how a vast majority of Americans support “fighting climate change” or “reducing carbon emissions” or “believe in global warming.” These vague, feel-good...