Carbon fluxes of inland and coastal waters in permafrost regions

Abstract:

Circum-arctic frozen soils contain twice as much carbon as is currently present as greenhouse gases in the atmosphere. Ongoing climate warming causes frozen soils to thaw, making the carbon available for microbial processing. This can generate greenhouse gases (fueling further global warming), both at the thaw site, but also during lateral transport in inland and coastal waters. Aquatic systems are increasingly recognized as reactive transport systems, but are generally not included in quantitative assessments of the magnitude of the permafrost carbon feedback. Combined carbon fluxes from lateral transport and aquatic gas emission can however be an important component of the total ecosystem carbon budget in Arctic regions. Here I aim to give an overview of our current knowledge on riverine and coastal organic carbon fluxes in permafrost regions, what factors determine the degradability (i.e. potential greenhouse gas production) of this organic carbon, and how we expect this to change in the future.