The hysteria about urban density that arrived with the coronavirus is—like the pandemic itself—already easing. Regardless of how quickly or slowly urbanites return to their cramped apartments, however, the long term trend is clear. Humans will continue to flock to cities. And that’s a good thing, because if we want to survive the next, much bigger crisis on the horizon, cities are our best bet. Cities currently consume two-thirds of the global energy supply and generate three-quarters of the world’s greenhouse-gas emissions. Luckily for human civilization, they’re also extraordinarily motivated to minimize their cost to the climate—and quickly. Because cities are uniquely vulnerable to climate change, they’re also likely to be remade the fastest by the human need to survive and eventually thrive on a warmer planet. Mayors and city managers across the world are turning urban centers into laboratories, implementing measures to cut air pollution and move toward […]