Kirk Johnson is the Sant Director of the Smithsonian’s National Museum of Natural History. Over his career as a geologist and paleobotanist, he has excavated and studied fossil plants from latitude 62°S to 82°N. His most recent book, Cruisin’ the Fossil Coastline: The Travels of an Artist and a Scientist along the Shores of the Prehistoric Pacific, was published last September. Over the last year, he has been filming Polar Extremes, a PBS NOVA special about the ancient climates of the polar regions.