Author and activist Bill McKibben has been on the front lines of the fight against climate change for decades, and as everyone north, east, south, and west of 1600 Pennsylvania Avenue seems to realize, the news about our warming planet gets a little more dire each day. Why are Americans still debating the existence of climate change as the world burns around us? For that, we can thank the oil industry in general and Exxon in particular. McKibben will review our fraught history and (hopefully) tell us just what to expect as the world keeps warming up. by Katie Herzog