13: Burn, Burn, Burn Again

Northern wildfires are changing so much that even their burn areas don't do what they used to do. Previously, if an area burned, we figured that was good for a couple of decades' protection. That ain't necessarily so any more. Marc-André Parisien is a Canadian Forest Service research scientist who's been studying this. He says we're seeing stuff that only just burned... burn again. "It's kind-of mindblowing."