Speaking from his home in Los Angeles, he recalls how he fought a good-natured “eco war” with his celebrity neighbour, Ed Begley Jr.; how climate change deniers can be defeated; and why the upcoming UN summit in Paris can be a turning point for our battle against global warming.   

Absolutely! [Pause] Anything else? [Laughs]. There’s enough energy in most places—wind, solar, tidal and geothermal—to run the whole world. What we need is to DO IT. We need to get started. What we want to do is provide electricity, worldwide communication via the Internet, and clean water to everyone in the world. This is absolutely doable from an engineering standpoint. But to get it done in a timely fashion we have