A pivotal role for air pollution during rapid Arctic change

Arctic warming is driving profound changes in the cryosphere and Arctic terrestrial environment, which are closely coupled with changes in atmospheric trace gases and aerosols. Arctic atmospheric composition is influenced by changes in anthropogenic pollutant emissions and responses of Arctic natural systems to climate change, and is central to Arctic climate feedbacks, ecosystem health, and well-being of Arctic residents. Warming is enabling increased Arctic human development and growing emissions from local anthropogenic sources such as resource extraction, shipping, and residential combustion, which are emerging in tandem with evolving natural emissions from vegetation fires, permafrost degradation, and changes in sea ice cover. These changes characterize a “New Arctic,” in which anthropogenic and natural emissions evolve and act together to modify the atmospheric radiative balance, Arctic clouds, and pollutant deposition, and affect human health. Here, we synthesize current understanding of two-way coupling between Arctic air pollution and environmental change, and identify knowledge gaps that should inform research priorities over the coming decade—in particular ahead of the 5th International Polar Year (IPY 2032–2033). Scientific priorities include addressing uncertainties in Arctic emissions, chemical processing, and impacts of pollution on Arctic clouds, ecosystems, and populations. New developments are needed to address severely limited observational coverage in the Arctic, particularly during winter and over the atmospheric vertical profile, to improve representations of Arctic-specific processes in models, and to integrate research with Indigenous knowledge. Coordinated international efforts are needed to address these challenges, leveraging new technologies and modeling frameworks. IPY 2032–2033 offers an opportunity to build and implement such collaborative research efforts, and development of coordinated observational and modeling efforts should begin during a ramp-up phase in the years ahead of IPY. Our recommendations offer a roadmap to advance understanding of the role of air pollution in the rapidly evolving and complex Arctic system