Vox: National governments have been notoriously slow to address global warming. But a lot of mayors -- from Seoul to New York to Rio de Janeiro -- are far more enthusiastic about tackling the problem. And, as it turns out, they can do a surprising amount by themselves.
A new report from the C40 Cities Climate Leadership Group argued that the world's biggest cities, on their own, could make roughly 15 percent of the emissions cuts needed to avoid 2°C of global warming. But they'd need to drastically...