Bloomberg: Arctic tundra may burn more frequently as the warming climate allows flammable vegetation to creep northward, U.S. scientists said. An analysis of Arctic sediments from thousands of years ago showed bigger shrubs were more common — as were fires that destroyed them, researchers led by Philip Higuera at Seattle’s University of Washington found. With plant life again increasing, fires could become more frequent, Higuera said. “There is evidence of increasing shrub biomass in …