Barack Obama on food and climate change: 'We can still act and it won't be too late'

The former president addresses the greatest challenges facing the world, and what we can do about them During the course of my presidency, I made climate change a top priority, because I believe that, for all the challenges that we face, this is the one that will define the contours of this century more dramatically perhaps than the others. No nation, whether it's large or small, rich or poor, will be immune from the impacts of climate change. We are already experiencing it in America, where som...