Arctic and boreal carbon

This chapter summarizes the current knowledge in high-latitude (mostly permafrost) carbon storage and dynamics. Arctic and boreal regions contain large carbon stock, especially in permafrost soils. The factors that control carbon storage have been changing rapidly over the last several decades. As a result, this large carbon pool is highly vulnerable for carbon loss in a future warming climate. There are major needs to reconcile model and observations in assessing permafrost carbon balance and in understanding the importance of abrupt thaw of permafrost.