Assessing the impact of shipping emissions on air pollution in the Canadian Arctic and northern regions: current and future modelled scenarios

摘要

The navigability of the Arctic Ocean is increasing with the warming in recent years. A first regional assessment of the impact of shipping emissions on air pollution in the Canadian Arctic and northern regions was conducted. Model simulations were carried out on a limited-area domain (at 15-km horizontal resolution) centred over the Canadian Arctic, using the Environment and Climate Change Canada's on-line air quality forecast model (GEM-MACH), to investigate the contribution from the marine shipping emissions over the Canadian Arctic waters, at both present and projected future levels, to ambient concentrations of criteria pollutants (O3, PM2.5, NO2, and SO2), atmospheric deposition of sulphur and nitrogen, and atmospheric loading and deposition of black carbon in the Arctic. The study found that shipping emissions have a local-to-regional impact in the Arctic at the current level: Arctic shipping emissions contribute to less than 1% of ambient O3 concentration over the eastern Canadian Arctic and between 1 and 5% of ambient PM2.5 concentration over the shipping channels; Arctic shipping emissions make a much greater contributions to the ambient NO2 and SO2 concentrations, at 10 - 50% and 20 -100 %, respectively. At the projected 2030 business-as-usuaf (BAU) level, the impact of Arctic shipping emissions is predicted to increase to up to 5% in ambient O3 concentration over a broad region of the Canadian Arctic and to 5 - 20% in ambient PM2.5 concentration over the shipping channels. in contrast, if emission controls such as the ones implemented in the current North American Emission Control Area (NA ECA) are to be put in place over the Canadian Arctic waters, the impact of shipping to ambient criteria pollutants would be significantly reduced. For example, with NA-ECA-like controls, the shipping contributions to population-weighted concentration of SO2 and PM2.5 wouid be brought down to below the current level A manuscript based on this assessment study was recently accepted for publication in Atmospheric Chemistry and Physics. tn this talk we wiil highlight the main findings and implications from this study.