Cities
More than half the world’s population lives in urban areas. By 2050 cities will likely be bursting with two-thirds of the people on the planet. Since urban areas already account for an estimated 76 percent of CO2 emissions from energy use—and many are especially vulnerable to flooding and higher temperatures—it makes sense that city officials are taking on climate change. After all, doing so also gives them a shot at reducing pollution, improving aging infrastructure, and making their cities more attractive to residents and businesses.