“Humane” pulls a comparable bait-and-switch. The film’s premise is that climate changed has metastasized, to the point that none of the earth’s population has enough food, water, or resources. An emergency decree by the UN has dictated that every country will have one year to meet its population-reduction goal, which is to cull 20 percent of its people. In the unnamed country where the film is set (but it was shot in Canada, looks like Canada, and feels like Canada, so let’s call it Canada), citizens are invited to “enlist” — that is, to volunteer for euthanasia. If they do so, giving up their lives for the greater good, the government will pay them $250,000 tax free. In other words, they can die and help set up their families. “Humane” was written by Michael Sparaga, and one of the things that’s savvy about it is the way the film plays, almost subliminally, off the current mood of economic desperation. (Instead of just being horrified, we’re supposed to hear the terms of enlistment and think, “Not a bad deal.”)