O n today's show: Dr. Joseph Romm, a senior fellow at the Center for American Progress and former assistant secretary at the U.S. Department of Energy, discusses why Alaska had its hottest December on record. Ruth Goring shares how a family trip to Colombia — the first since childhood — inspired her new children’s book, which tells the story of a little girl whose family flees Colombia as refugees. Historian John Schmidt tells the story of Leon Trotsky, who was Vladimir Lenin's natural successor but was outmaneuvered by Joseph Stalin.