Celebrity scientist and PBS fixture David Suzuki arrives late to the global-warming-documentary party with this combination of biography and filmed lecture, his last, according to the billing. Director Sturla Gunnarsson doesn’t bring much new to the form beyond a welcome unobtrusiveness and a few fleeting moments of visual elegance. Suzuki’s unimpeachable cred as a longtime climate-change evangelist and swooning regard for the natural world do give the conversation a convincing, if depressing, urgency, but what sets Force of Nature apart is the sweeping diversity of his life. Born in Vancouver to second-generation Japanese-American parents, Suzuki was tossed into an internment camp as a child during WWII, participated in the burgeoning civil rights and eco movements in the 1960s, and leveraged his nascent academic stardom into a durable gig as host of the CBC’s The Nature of Things, among other shows. Gunnarsson ably juxtaposes the septuagenarian geneticist’s personal reflections with scenes from the lecture, and Suzuki’s probing, bittersweet recollections provide genuine insight into his gift for making connections most of us could never conceive. Suzuki’s not obscure by a long shot, and the film indulges in more than a little of the preening egotism for which he’s known (or, by his conservative critics, reviled). That doesn’t take away from the fact that he’s among the shrinking segment of public figures worth listening to, though.