Glob. Biogeochem. Cycles http://dx.doi.org/10.1029/2010GB003956 (in the press)

Credit: © ISTOCKPHOTO.COM/MICHA ADAMCZYK

Black-carbon aerosols — derived from the incomplete combustion of fossil fuels and biomass — alter the radiation balance of the planet. An analysis of coastal sediments in Sweden suggests that continental shelf sediments function as a sink for atmospheric black carbon.

Örjan Gustafsson of Stockholm University and colleagues examined the black-carbon content of sediments along a 2,000-km stretch of the Swedish continental shelf. Their analysis focused on the soot form of black carbon, which consists of nanometre- to micrometre-sized particles. Soot black carbon accounts for around 5% of the organic carbon in the studied sediments. Using previously published sonar data on the extent of sediment accumulation in the region, the researchers estimate that the Swedish continental shelf harbours around 4 Tg of soot black carbon, and sequesters around 300 Gg each year.

Scaling their analysis up, the team estimates that the North European shelf collects 1.1 Tg of soot black carbon from the atmosphere each year — similar in magnitude to European soot black carbon emissions.