Black carbon emissions from European shipping in the Arctic have been significantly underestimated, a new study suggests.
Produced by the incomplete combustion of fuels in ship engines, black carbon is contributing to the rapid loss of Arctic sea ice.
Previous reports have only focused on vessels flying EU flags, overlooking the impact of ships travelling to and from EU ports.
“Our findings show that ships connected to EU trade, regardless of their flag, are major drivers of black carbon pollution in the Arctic,” says Liudmila Osipova, senior researcher at the International Council on Clean Transportation (ICCT), and lead author of its new study.
“Recognising these emissions in future policies could help the EU better align its climate goals with its real footprint in the Arctic.”
Black carbon emissions doubled in six years
As Arctic shipping activity increases, so too are the associated black carbon (BC) emissions.
Between 2015 and 2021, BC emissions in the International Maritime Organisation (IMO)’s definition of the Arctic nearly doubled, according to the study.
In the more broadly defined Geographic Arctic, shipping emitted 1.5 kilotonnes (kt) of BC and 12 kt of CO₂ in 2021. About a quarter of these emissions occurred within the IMO definition of the Arctic, indicating a strong growth in BC emissions in the polar area, from 193 tonnes in 2015 to 413 tonnes six years later.
How does black carbon melt sea ice?
This growth trend is concerning, since one tonne of black carbon has a global warming effect equivalent to 900 tonnes of CO₂, as it absorbs more heat in the atmosphere.
BC’s impact is particularly pronounced in the Arctic. When the sooty particles settle on snow or ice, they reduce the albedo of these surfaces, meaning they reflect less light and so melt faster.
This compounds the climate challenges in a region which is already heating up three to four times faster than the global average.
Despite its potent climate and health impacts - it is linked to lung cancer, respiratory illness, and cardiopulmonary disease - BC remains one of the most unregulated short-lived climate and air pollutants.
The hidden carbon cost of EU trade in the Arctic
Brussels typically only accounts for the emissions from its EU-flagged ships in the Arctic. To give a truer picture of the pollution over which the bloc has control, ICCT has also totted up BC and CO₂ from EU-regulated ships, which answer to the EU Monitoring, Reporting, and Verification (MRV) system as they voyage between EU ports.
These vessels are the bigger polluters, it found. BC and CO₂ emissions from EU-regulated ships of at least 5,000 gross tonnage were nearly double those from EU-flagged ships in the IMO Arctic in 2021.
That year, nearly three-quarters of the ships operating in the Geographic Arctic and half of those in the IMO Arctic were navigating to or from EU ports.
To address a significant gap in its maritime regulation, the researchers say that EU policymakers could include BC among the pollutants measured and reported within the bloc’s MRV system.
Beyond improved emissions tracking, there are various ways to reduce BC emissions, such as incentivising ships to use distillate instead of residual fuel, and encouraging the installation of diesel particulate filters on board.
