1CICERO, Center for International Climate and Environmental Research Oslo, Norway
2College of Earth, Ocean, and Atmosphere, University of Delaware, Newark, USA
3The International Council on Clean Transportation, San Francisco, USA
4NOAA Earth System Research Laboratory, Chemical Sciences Division, Boulder, USA
5Cooperative Institute for Research in Environmental Sciences, University of Colorado, Boulder, USA
Abstract. We quantify the concentrations changes and Radiative Forcing (RF) of short-lived atmospheric pollutants due to shipping emissions of NOx, SOx, CO, NMVOCs, BC and OC. We use high resolution ship emission inventories for the Arctic that are more suitable for regional scale evaluation than those used in former studies. A chemical transport model and a RF model are used to evaluate the time period 2004–2030, when we expect increasing traffic in the Arctic region. Two datasets for ship emissions are used that characterize the potential impact from shipping and the degree to which shipping controls may mitigate impacts: a high (HIGH) scenario and a low scenario with Maximum Feasible Reduction (MFR) of black carbon in the Arctic. In MFR, BC emissions in the Arctic are reduced with 70% representing a combination technology performance and/or reasonable advances in single-technology performance. Both scenarios result in moderate to substantial increases in concentrations of pollutants both globally and in the Arctic. Exceptions are black carbon in the MFR scenario, and sulfur species and organic carbon in both scenarios due to the future phase-in of current regulation that reduces fuel sulfur content. In the season with potential transit traffic through the Arctic in 2030 we find increased concentrations of all pollutants in large parts of the Arctic. Net global RFs from 2004–2030 of 53 mW m−2 (HIGH) and 73 mW m−2 (MFR) are similar to those found for preindustrial to present net global aircraft RF. The found warming contrasts with the cooling from historical ship emissions. The reason for this difference and the higher global forcing for the MFR scenario is mainly the reduced future fuel sulfur content resulting in less cooling from sulfate aerosols. The Arctic RF is largest in the HIGH scenario. In the HIGH scenario ozone dominates the RF during the transit season (August–October). RF due to BC in air, and snow and ice becomes significant during Arctic spring. For the HIGH scenario the net Arctic RF during spring is 5 times higher than in winter.