As the cruise industry revives post-pandemic, cruisers visiting Croatia are now emitting over one third of the sulphur dioxide produced by the country’s entire car fleet, a study by the NGO Transport & Environment has revealed. 

It finds that air pollution caused by cruise ships near ports in Europe now surpasses the levels recorded before the pandemic. Despite the implementation of the UN shipping body's sulphur cap in 2020, Europe's 218 cruise ships emitted an equivalent amount of sulphur oxides (SOx) to that produced by 1bn cars.

The study compared data from 2019 to the present, finding the number of cruise ships operating near ports, the duration of their stay and the amount of fuel consumed all rose by approximately 23-24%. Consequently, there was a 9% rise in SOx emissions, an 18% increase in NOx emissions and a 25% jump in PM2.5 emissions, three types of toxic air pollutants assessed in the report. 

This escalation poses a severe threat to the air quality in Europe's port cities, with the worst affected being Barcelona, Civitavecchia northwest of Rome, and Piraeus, the port serving Athens.

“The pandemic provided some respite for port cities, but this is now well and truly over. Cruising is back and tourist hotspots like Barcelona and Athens are again choking on toxic air pollution from cruise ships,” said Constance Dijkstra, shipping campaigner at T&E. 

The study is based on data on cruise ships with a gross tonnage (GT) exceeding 5,000 that made port stops in Europe in both 2019 and 2022. This included 173 ships in 2019 and 214 ships in 2022.

T&E then compared ship pollution with car pollution at selected port cities and countries where cruise ships sailed through their Exclusive Economic Zones (EEZs). Car pollution data is based on European Union Transport Roadmap Model (EUTRM) car emission data based on the assumption that the car fleets consisted entirely of diesel vehicles, which have poorer NOx performance compared to petrol cars. The final results thus likely underestimate the extent of air pollution from cruise ships in comparison to cars, many of which run on petrol rather than diesel. 

T&E points out that the SOx limits for cars in Europe are 100 times more stringent than those applicable to ships.

Emissions in Croatia 

72 cruise ships visited Croatia or passed through Croatian waters, emitting a total of 672 tonnes of SOx. This is roughly equivalent to 35.1% of the SOx emitted by the 1.6mn cars on Croatia’s roads. 

Meanwhile, cruise vessels were responsible for more NOx than half Croatia’s national car fleet.

Top cruise destinations in Croatia include the ancient walled city of Dubrovnik and Croatia’s second city of Split. 

While the amount of pollution emitted by cruisers in Croatia is significant compared to the size of the country’s car fleet, in absolute terms the amount of SOX emitted by cruise ships is more than twice as high in several West European countries. 

Italy has now overtaken Spain to hold the title of the most polluted country. 

Outside Mediterranean region, Norway ranked fourth in the pollution ranking; while it has the highest volume of cruise traffic among all countries, the ships tend to be smaller in size.

In Barcelona, the emissions from cruise ships were nearly three times higher in terms of SOx compared to the combined emissions from all the cars in the city.

Other countries in the Central and Southeast European region were less affected. The number of cruise ships visiting ranged from 29 in Lithuania to 48 in Estonia.

Among cruise ship operators, MSC Cruises emerged as the most significant contributor to pollution, T&E said. The emissions from their cruise ships were almost equivalent to the combined SOx emissions produced by all passenger vehicles throughout Europe. 

However, when taking into account all of its subsidiaries, the Carnival group ranked as the highest-polluting entity in the industry.

Several Mediterranean cities have considered a ban on cruise ships. In 2021, Venice banned large cruise ships from entering its port, after which emissions from cruise ships witnessed an 80% decline. It went from one of the most polluted due to cruise ship activities in 2019, to 41st position in terms of pollution levels last year. 

While Croatian cities have not yet imposed a ban, in 2018 the mayor of Dubrovnik capped the number of cruise ships to two per day with a total of 5,000 tourists. The aim was to tackle overcrowding in the city, rather than being targeted at reducing pollution. 

Greener shipping 

As bne IntelliNews has reported, the shipping industry is a major polluter, and efforts are underway to make it greener, including through electrification and the introduction of new solar and wind power technologies.

“Despite there being only about 100,000 vessels in the world, the sector is one of the leading sources of greenhouse gas (GHG) emissions, air and water pollution,” T&E warned. “The sector still relies almost entirely on fossil fuels of the dirtiest kind, full of toxic substances including sulphur. This is the result of regulatory standards on marine fuels lagging far behind those applicable to other modes of transport.” 

According to the NGO, the best marine sulphur standard remains 100 times worse than Europe’s sulphur standard for road diesel and petrol that has been in place for the past 15 years.

It calculates that shipping contributes to roughly 3% of global anthropogenic GHG emissions, and is responsible for an estimated 250,000 premature deaths per year from cancer and cardiovascular diseases.

“Venice has shown that tackling cruise ship pollution is possible, but bans aren’t the only way. Ports can significantly reduce pollution levels by forcing ships to plug into electricity at the port instead of running their engines, and by supporting the adoption of zero-emission fuels,” said Dijkstra, as quoted in T&E’s press release. 

The report notes that cruise operators are increasingly turning to fossil gas (LNG), with over 40% of the cruise ships ordered this year designed to be powered by the fuel. However, T&E warns that while these ships offer advantages in terms of reducing air pollution, they pose significant climate concerns due to methane leaks from their engines.