As out-of-control wildfires burned hundreds of homes in southern British Columbia this August, Cliff Chapman, director of operations for the province’s wildfire service, issued a sobering statement. “I cannot stress enough that the conditions we are facing right now are conditions that we have never seen before,” he told reporters.

Mr. Chapman, who has been fighting wildfires for over 20 years, could have made the same statement from Washington State, Croatia or many other places where similarly explosive wildfires have scorched neighborhoods and forced mass evacuations. These fast-moving, virtually irrepressible events are not the seasonal burns of decades past; they are the hazard lights of a heating climate, and they are flashing furiously. Rural and urban, East and West, we are entering a new era of civilizational risk and retreat.