Projected emissions and climate impacts of Arctic shipping along the Northern Sea Route

The navigability of Arctic maritime passages has improved with the rapid retreat of sea ice in recent decades, and it is projected that the Northern Sea Route (NSR) will support further increases in shipping in the future. However, the opening of the NSR may bring potential environmental and climate risks to the Arctic and the rest of the world. This investigation assessed shipping emissions along the NSR and the climate impacts under global warming of 2 °C and 3 °C to support coordinated international decision-making. The results show that the magnitude of annual energy consumption of ships along the NSR is 10⁹ kWh under global warming of 2 °C and 3 °C. The environmental impacts of the shipping decrease with fuel transition to clean, carbon-neutral fuel sources. Specifically, the maximum emission is CO₂ (10⁶ t), followed by NO_X (10^4-5 t), CO (10^3-4 t), SO_X (10³ t), CH₄ (10^2-3 t), organic carbon (10^2-3 t), N₂O (10^1-2 t), and black carbon (BC, 10^1-2 t), in which CO₂ and BC have great difference under high and low loads. Total emission exacerbates Arctic and global warming, and it is more significant in the Arctic in the next twenty years and across the rest of the world in the next one hundred years. The greatest climate impact factor is CO₂, followed by NO_X and BC which are more important in global and Arctic warming, respectively.