Cleaner air in the high north could reduce Arctic sea ice by an area of about one million square kilometres this century.

Air pollution has a net cooling effect on the climate, and has partially offset the decline of Arctic sea ice since the mid-1970s. John Fyfe and his colleagues at the Canadian Centre for Climate Modelling and Analysis in Victoria, Canada, used an Earth-system model to simulate sea-ice changes in the twenty-first century with and without projected reductions of global aerosol emissions. Cleaner air accounted for 15–40% of the Arctic ice melting simulated under a range of greenhouse-gas emission scenarios.

In a model with high greenhouse-gas emissions and large projected reductions in air pollution, the Arctic Ocean became seasonally ice-free in 2045 — 12 years earlier than when aerosol emissions were held at 2000 levels.

Geophys. Res. Lett. http://doi.org/7tt (2015)