Huge Arctic fire had big impact on carbon cycle

BBC : A paper published today in Nature warns of a feedback mechanism that could accelerate the impact of global warming in the Arctic region. The unusually dry summer of 2007 helped to fuel the Anaktuvuk River fire, which destroyed as much Alaskan tundra as did all previous fires since 1950. Led by Michelle Black of the University of Florida in Gainesville, the paper’s authors determined that the Anaktuvuk River fire burned vegetation down to depth of 15 cm and released into the atmosphere 50 years’ worth of sequestered carbon. Because increasing the amount of atmospheric carbon dioxide raises global temperatures, Arctic wildfires could become more frequent and widespread. And if that happens, Mack and her colleagues warn, even more sequestered carbon could be released and lead to a vicious cycle of runaway warming.