Next in Ohio State’s 2017 Environmental Film Series is “A Race Against Time,” which looks at global solar energy development. David Letterman, retired host of “The Late Show,” explores how India is using solar to expand its electrical service, power its economy, and bring electricity to 300 million people who’ve never had it before. In Florida, “Saturday Night Live” cast member Cecily Strong gets the inside story on what’s been blocking solar’s growth in America. The film is an episode in the National Geographic Channel’s “Years of Living Dangerously” series. It screens at 7 p.m. Tuesday, Feb. 14, in Columbus. Free admission. Location and other details here.