Wisser, D., Marchenko, S., Talbot, J., Treat, C., and Frolking, S.: Soil temperature response to 21st century global warming: the role of and some implications for peat carbon in thawing permafrost soils in North America, Earth Syst. Dynam., 2, 121-138, doi:10.5194/esd-2-121-2011, 2011.
Northern peatlands contain a large terrestrial carbon pool that plays an important role in the Earth’s carbon cycle. A considerable fraction of this carbon pool is currently in permafrost and is biogeochemically relatively inert; this will change with increasing soil temperatures as a result of climate warming in the 21st century. We use a geospatially explicit representation of peat areas and peat depth from a recently-compiled database and a geothermal model to estimate northern North America soil temperature responses to predicted changes in air temperature. We find that, despite a widespread decline in the areas classified as permafrost, soil temperatures in peatlands respond more slowly to increases in air temperature owing to the insulating properties of peat. We estimate that an additional 670 km3 of peat soils in North America, containing ~33 Pg C, could be seasonally thawed by the end of the century, representing ~20 % of the total peat volume in Alaska and Canada. Warming conditions result in a lengthening of the soil thaw period by ~40 days, averaged over the model domain. These changes have potentially important implications for the carbon balance of peat soils.
Earth System Dynamics (ESD) is an international scientific journal dedicated to the publication and public discussion of studies that take an interdisciplinary perspective of the functioning of the whole Earth system and global change. The overall behavior of the Earth system is strongly shaped by the interactions among its various component systems, such as the atmosphere, cryosphere, hydrosphere, oceans, pedosphere, lithosphere, and the inner Earth, but also by life and human activity. ESD solicits contributions that investigate these various interactions and the underlying mechanisms, ways how these can be conceptualized, modelled, and quantified, predictions of the overall system behavior to global changes, and the impacts for its habitability, humanity, and future Earth system management by human decision making. More at Earth System Dynamics homepage.