The International Maritime Organization's Marine Environment Protection Committee has adopted an emission control area covering the Northeast Atlantic, with the regulation set to enter into force in September 2027.

The Atlantic ECA will require ships operating in waters stretching from Portugal to Greenland, via Britain and Ireland, to significantly reduce sulfur oxide and nitrogen oxide emissions by using cleaner fuels or equivalent technologies.

The adoption follows a failed attempt to pass the measure during an IMO meeting in October 2025, when coastal states first proposed the zone to reduce air pollution from shipping.

According to environmental groups involved in the process, the new ECA will connect existing emission control areas in the North and Baltic Seas, recently adopted zones in Canadian Arctic waters and Norway's exclusive economic zone, to the Mediterranean SECA in the south.

Sönke Diesener, shipping expert at NABU, remarked: "Besides cleaning up the air, ECAs also have a remarkable benefit for the climate: high-quality fuels reduce ground-level ozone formation and drive energy efficiency, causing a reduction in fuel consumption and thereby CO2 emissions."

The regulation is expected to reduce black carbon emissions from ships switching from heavy fuel oil to distillate fuels. Black carbon, or soot, has been identified as a contributor to Arctic warming due to its heat-absorbing properties when deposited on ice.

Dr Kåre Press-Kristensen, senior adviser at Green Global Future, commented: "On top of being very damaging to public health, soot is the key reason that the Arctic is warming four times faster than the rest of the world: soot deposits on and darkens ice and thereby increases absorption of sunlight, leading to warming and melting of the ice."

However, environmental groups have called for additional measures to maximise the ECA's effectiveness, particularly a ban on exhaust gas cleaning systems, commonly known as scrubbers, which allow ships to continue burning high-sulphur fuel while treating exhaust gases.

Dr Liudmila Osipova, who led the impact assessment report submitted to the IMO, said research shows that banning scrubbers could reduce black carbon emissions by over 30% in the Atlantic ECA and prevent at least 300 premature deaths by 2050. Denmark, Finland and Sweden have already introduced scrubber bans in their waters.

Carolina Silva, shipping policy officer at ZERO, noted that Portuguese islands including Madeira and the Azores, as well as Spain's Canary Islands, remain outside the ECA boundaries despite their coastal communities facing air pollution from shipping.

The Clean Arctic Alliance reported that Russia has indicated it will not follow the ECA requirements, despite the zone's proximity to Russian waters. Dr Sian Prior, lead adviser to the organisation, called for additional IMO regulations directly limiting black carbon emissions throughout the wider Arctic region.

Under MARPOL Annex VI regulations, ships operating within emission control areas must use fuel with a sulfur content not exceeding 0.10%, compared with the global limit of 0.50% outside designated zones.