U.S.‐Russia venture probes Siberian peatlands' sensitivity to climate

Abstract

The extent to which northern peatlands respond to or influence climate change is an unresolved question in Arctic science. Recent studies in Alaska, Canada, and Fennoscandia have raised concerns that northern peatlands, while currently a net sink or minor source of atmospheric CO 2 , may become a significant CO 2 source under a warming climate. Expanding peatlands emit methane but sequester atmospheric carbon through long‐term accumulation of undecomposed plant matter. Drier conditions may reverse this process by increasing temperatures and lowering the peatland water table, causing anaerobic decomposition of stored peat and subsequent outgassing of CO 2 .While this process would likely reduce methane emissions and possibly enhance C uptake from increased soil nutrient mineralization rates [ Oechel and Vourlitis , 1994], many scientists now believe that warming and drying of northern peatlands will liberate stored C for uptake by the atmosphere and biosphere.