In which Undark’s podcast anchor, former NYT Science Times Editor David Corcoran, discusses the science of pesticides and marijuana agriculture with Brooke Borel, author of a recent Undark investigation. Also on tap: Undark’s Tracker columnist, Paul Raeburn, talks about advocacy and journalism, while Ian Cheney contemplates the scale of the climate conundrum in an audio version of his short documentary for Undark, “The Measure of a Fog.”