In June, President Obama's landmark speech at Georgetown University delivered a powerful message on the dangers the world faces from global warming – extreme weather, rising seas, increased wildfires, epic droughts. "We will be judged," he said, "as a people, as a society, and as a country, on where we go from here." So where do we go? In his first term, Obama enacted tougher vehicle mileage standards and doubled electricity from renewables. But he's still got a long way to go. Here are a few things the president could achieve in his second term.