When I caught up with Rob Hopkins at the SXSW Eco conference in Austin, Texas, this week, he had just ended a seven-year, self-imposed airplane fast. This is a guy who takes the climate fight — and the power of individual actions — seriously. A few years back, he launched Transition Towns, aimed at helping communities lead the way into a post-fossil-fuel world. The movement has since spread around the globe.

Hopkins, a Brit, said he climbed on a plane again to attend a meeting of the Environmental Grantmakers Association, and try to convince foundations to pour money into transition efforts. He was in Austin speaking at SXSW and kicking off a whirlwind tour to promote his new book, The Power of Just Doing Stuff: How Local Action Can Change the World. When that’s done, he’s grounded again: “People say, ‘Oh, you’re flying again,’” he said. “I’m not flying again. I flew once.”