Arctic and sub-Arctic soil emissions: possible implications for global climate change

摘要: Climate models predict a substantial warming at high latitudes following the enhanced greenhouse effect caused by anthropogenic emissions of carbon dioxide (CO 2 ), methane (CH 4 and various other trace gases. Arctic sub-Arctic soils contain large amounts organic that could be made increasingly available for decomposition in wanner climate due to deepening biologically-active layer increased thermokarst erosion. This produces potential CO CH from tundra areas thus positive (enhancing) feedback effects on effect. From being net absorber global become source up 1.25 Gt C yr 1 as result predicted warmer dryer conditions during thaw period. is least 21 times more effective gas than . How balance will respond change therefore very important but also much less certain. Estimates total present northern wetlands vary greatly, ranging 2.4 106 Tg little known about mechanisms controlling flux. There are indications, however, if becomes wetter under warming, would probably increase. If it dryer, cease or even turn into sink atmospheric , partly increasing microbial consumption soil. an urgent need research processes flux soils.