A study led by the École Polytechnique Fédérale de Lausanne (EPFL) suggests that shipping emissions influence climate-relevant cloud formation and may impact regional climate processes far beyond the polar region.
Original article by Hector Garcia Morales, ENAC, source EPFL (École Polytechnique Fédérale de Lausanne). This is a slightly shorter version of the original.
Over the last few decades, the Arctic has lost roughly half of its September sea ice. At the same time, the melting of the Arctic is freeing previously inaccessible shipping routes. According to recent estimates, maritime traffic through the Arctic has increased by forty per cent in the last twelve years, and by 2100, traffic in the polar region could surpass that of the Suez and Panama Canals. Moreover, the current geopolitical context in the Middle East intensify the situation by diverting vessel transits.
Impact on air quality
Yet, a sudden increase in traffic can raise concerns about its impact on the air quality of the polar atmosphere. Therefore, a study led by Julia Schmale, tenure-track assistant professor, and Benjamin Heutte, PhD student at the Extreme Environment Research Laboratory, evaluated the impact of aerosol emissions from vessels operating in polar waters.
Published in Environmental Research Letters, the study finds that emissions from a single vessel increased local cloud radiative power by as much as 22 per cent, meaning that clouds retained substantially more heat than under clean conditions. These changes in the polar ecosystem can influence regional climate processes and may affect weather patterns in lower latitudes.
Also read: Increasing maritime traffic poses threat to Arctic whales
Taking advantage of ‘unwanted’ data
The research was carried out aboard the research vessel Polarstern during the MOSAIC expedition, which aimed to improve understanding of rapid climate change in the Arctic. Scientists initially set out to study natural aerosols and pollution transported from lower latitudes, but discovered that around sixty per cent of their measurements had been contaminated by the vessel’s own exhaust, with pollution levels up ten to 100 times higher than the Arctic background.
Rather than discard the data, the researchers turned the contamination into an opportunity to investigate how ship emissions affect Arctic clouds. By analysing the exhaust plume, they were able to measure how emissions alter atmospheric conditions and influence cloud formation, providing valuable insight into the environmental impact of shipping in the region.
Cleaner fuels alone are not enough
Researchers found that ship emissions can significantly influence Arctic cloud formation, even when vessels operate on low-sulphur fuels. Polluted clouds act like a blanket, trapping more heat and potentially accelerating sea ice melt. By combining field measurements with atmospheric models, the team assessed how far emissions can spread and continue to affect cloud development.
They also concluded that cleaner fuels alone are not enough to eliminate shipping’s environmental impact. The findings will be incorporated into larger models that account for fuel types, engine technologies and shipping routes, while also considering the effects of exhaust deposits on the wider Arctic ecosystem.
From the Arctic to Switzerland
Changes in the Arctic climate can have far-reaching effects beyond the polar region. Declining sea ice influences temperatures, atmospheric moisture and the polar vortex, potentially altering winter weather patterns across Europe, including heavier snowfall in regions such as Switzerland.
The researchers will continue investigating the impact of Arctic shipping during the upcoming Tara Polar Station expedition, which departs France in July. The mission will collect data on climate, atmospheric processes, pollution and biodiversity to support policies aimed at protecting the Arctic, a region warming nearly four times faster than the global average.
Also read: No more HFO in Arctic waters from 2024
