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Tackling air pollution from ships: three facts about the freshly adopted Med SOx ECA

16 December 2022

On 15 December 2022 the 79th session of the International Maritime Organization’s (IMO) Marine Environment Protection Committee (MEPC 79) adopted the Mediterranean Sea Emission Control Area for Sulphur Oxides and Particulate Matter (Med SOx ECA), with effect from 1 May 2025, to further limit air pollution from ships, pursuant to Annex VI to the International Convention for the Prevention of Pollution from Ships (MARPOL).

The Mediterranean Sea has thus become the fifth area worldwide to be designated as an Emission Control Area for Sulphur Oxides and Particulate Matter. This historic development rewards efforts by the Contracting Parties to the Convention for the Protection of the Marine Environment and the Coastal Region of the Mediterranean (Barcelona Convention) to curb harmful pollutants emitted from ships operating in the Mediterranean Sea.

Here are three facts illustrating the importance of Med SOx ECA in the Mediterranean and beyond:

Tailwind to greener shipping in the Mediterranean
The Mediterranean Sea is home to some of the busiest maritime routes in the world, supporting 20 per cent of seaborne trade. It is estimated that 24 per cent of the global fleet of ships and more than 17 per cent of worldwide cruises plied the Mediterranean Sea in 2019. Pollutants emanating from fuel combustion, including Sulphur Oxides (SOx) and Particulate Matter (PM), result in health hazards and adverse environmental impacts.

Once it comes into effect on 1 May 2025, ships operating in Med SOx ECA will be required to comply with a limit for sulphur content in fuel oil that is a fifth of the legal limit outside this area (0.10 per cent mass by mass (m/m), compared with 0.50 per cent m/m allowed outside Med SOx ECA).

With this achievement secured, the UNEP/MAP-Barcelona Convention system will direct its attention to Nitrogen Oxides (NOx), another type of air pollutants emitted by ships, and will continue to support IMO’s work on the decarbonization of international shipping.

Considerable benefits for people and nature
Med SOx ECA will translate into a 78.7 per cent drop in SOx emissions and an annual reduction of 8.5 million tonnes of SOx released into the atmosphere. In addition, emissions of Particulate Matter (PM 2.5) will be slashed by 23.7 per cent.

Lower levels of pollutants will benefit aquatic and land ecosystems, notably by preventing acidification. According to studies undertaken by UNEP/MAP, human health-related benefits include the prevention of 1,100 premature deaths and 2,300 cases of childhood asthma every year.

Curbing SOx emissions will also be good news for road users in coastal areas and seafarers, as it will enhance visibility and transport safety both inland and at sea across large swathes of North Africa and in the Strait of Gibraltar.

Environmental multilateralism at its best
In the Mediterranean region, countries are situated at different levels of economic development and disparities can be significant. Capping the sulphur content in fuel oil used on board ships at one fifth of the legal limit (which is applicable outside Emission Control Areas) was always going to generate an additional burden of compliance. Yet this has not prevented the proposal for the designation of the Med SOx ECA from going forward. The Contracting Parties to the Barcelona Convention and its Protocols had effectively reached consensual decisions pertaining to the Med SOx ECA at their 21st meeting (Naples, Italy, 2-5 December 2019) and 22nd meeting (Antalya, Türkiye, 7-10 December 2021). Mediterranean solidarity—a principle that the UNEP/MAP-Barcelona Convention system upholds—has prevailed.

UNEP/MAP acted as a forum for the intergovernmental negotiations on the Med SOx ECA and catalysed progress at the regional level, including through the scientific and technical support provided by the Regional Marine Pollution Emergency Response Centre for the Mediterranean Sea (REMPEC) and the Plan Bleu Regional Activity Centre.

The next step will be for UNEP/MAP to join forces with IMO and REMPEC to secure the ratification of MARPOL Annex VI by the six Mediterranean countries that have not yet done so. Securing this ratification by 1 May 2024 is required to ensure the uniform and effective application of Med SOx ECA when it comes into force on 1 May 2025.