Ferries emit ‘more sulphur pollution than cars’ in several EU capitals
A Transport & Environment study finds ferries in several EU port cities release more sulphur oxides than cars, highlighting a hidden source of air pollution. The report outlines how electrification could cut emissions and details steps taken by ports such as Dublin, Stockholm and Tallinn.
New research from the clean‑transport watchdog Transport & Environment (T&E) reveals that ferries operating in a number of Europe’s biggest port cities emit more sulphur oxides (SOx) than the entire fleet of road vehicles within the same urban area. The analysis, based on emissions modelling for the 100 busiest European ferry ports, places Dublin, Helsinki, Stockholm and Tallinn among the 13 capitals where ferry‑related SOx concentrations exceed those from cars.
Why ferries matter in the urban air picture
Europe still runs close to 2,000 ferries, many of which are powered by heavy fuel oil that contains up to 0.5% sulphur – far above the 0.1% limit imposed on ships in the North Sea, Baltic Sea and, from 2025, the Mediterranean. When burnt, this fuel releases toxic gases that smell of burnt matches and rotten eggs. The gases quickly form fine particulate matter that can penetrate deep into the lungs, enter the bloodstream and cause long‑term health problems.
Unlike large ocean‑going vessels that spend most of their time far from shore, ferries typically operate within five nautical miles of densely populated ports. Their short routes and frequent sailings mean that residents are exposed to emissions on a regular basis, often more intensely than from road traffic that is dispersed over a wider area.
Key findings of the T&E report
- Ferries are the dominant source of SOx in 13 of Europe’s 15 largest port cities, outpacing cars in Dublin, Helsinki, Stockholm, Tallinn, Barcelona, Marseille, Rotterdam and Valencia.
- In Athens, Rome and Malta’s capital Valletta, ferries also emit more sulphur than road vehicles, but the cities were excluded from the ranking because their ports are classified as separate municipalities.
- Electrifying 20% of Europe’s ferry fleet would have been technically feasible and cost‑effective by 2025; the share could rise to 43% by 2030 as battery costs fall.
- Charging infrastructure is the main obstacle to wider adoption, yet most ports would only need low‑power (<5 MW) chargers to support electric ferries on short routes.
- EU policy already mandates a 0.1% sulphur limit and requires passenger and container ships to use shore power by 2030, but massive investment in clean fuels and port electricity is still lacking.
Port responses and electrification pilots
Several ports are already moving toward cleaner operations. Dublin Port Company is studying a green shipping corridor on the Dublin‑Holyhead route and is in talks with the Irish government and the national grid about installing shore‑side power. Stockholm’s port authority notes that most ferry operators already meet sulphur limits and that many vessels connect to on‑shore power while berthed, cutting CO₂, SOx and NOx emissions.
In Tallinn, the port has equipped five quays with shore power and is evaluating hybrid or fully electric solutions for the heavily trafficked Tallinn‑Helsinki line, one of the world’s busiest short sea routes. The first hybrid ferry is slated to enter service in early 2026, with a fully electric vessel under design. Helsinki’s sustainability chief stresses that ports need firm commitments from shipping lines before committing to large‑scale charging infrastructure.
What the transition could look like
If the projected electrification rates are achieved, the EU could see a dramatic reduction in urban SOx levels, improving public health and meeting tighter air‑quality standards. Battery technology is advancing rapidly, and the cost of marine‑grade lithium‑ion packs is falling, making electric ferries increasingly competitive with diesel‑powered vessels on routes under 100 km.
However, the shift requires coordinated action: shipowners need to order electric builds, ports must install compatible chargers, and governments must provide financing mechanisms for the upfront capital. The European Community Shipowners’ Association acknowledges the EU’s ambitious targets but warns that “enormous” investments are still needed in clean fuels, energy storage and port infrastructure.
Looking ahead
While the current data paints a concerning picture of ferry‑related sulphur pollution, the same analysis also highlights a clear pathway to cleaner seas. Continued monitoring, stronger regulatory enforcement and targeted subsidies for electric ferries could turn the tide, delivering fresher air to millions of coastal residents across Europe.
Why it matters
Ferry‑generated sulphur pollution directly affects air quality in densely populated port cities, posing health risks and undermining EU climate goals.
Key points
- Ferries emit more sulphur oxides than cars in 13 major EU port cities
- Electrifying 20% of the fleet was feasible by 2025; 43% by 2030 is realistic
- Charging infrastructure is the main barrier, yet most ports need only low‑power chargers
- Ports in Dublin, Stockholm and Tallinn are piloting shore‑side power and hybrid vessels
- EU policies set strict sulphur limits, but massive investment is still required
Frequently asked questions
Which EU capitals have the highest ferry sulphur emissions?
Dublin, Helsinki, Stockholm and Tallinn rank among the highest, with ferries releasing more sulphur oxides than all road vehicles in each city.
Can ferries be electrified with current technology?
Yes. T&E’s modelling shows that 20% of Europe’s ferries could have been electrified cost‑effectively by 2025, rising to 43% by 2030 as batteries improve.
What is the main obstacle to wider ferry electrification?
The lack of shore‑side charging infrastructure, although most ports would only need chargers below 5 MW for short routes.
What steps are ports taking to reduce emissions?
Dublin is exploring shore power and a green corridor, Stockholm already supplies on‑shore power to many ferries, and Tallinn has installed shore power at five quays and is testing hybrid vessels.
