NABU Cruise Ranking 2025

Climate target

On a positive note, all shipping companies considered continue to be committed to their net-zero target for 2050. Accordingly, they aim to capture as many greenhouse gases annually as they emit by that date, so that their total emissions balance out to zero. However, the shipping companies show little sign of planning to achieve this before 2050. 

Climate and efficiency measures

Efficiency improvements in ships are achieved through measures such as improved energy management on board, route optimisation combined with slow steaming, but also adjustments to the hull shape and the ship's propeller. In rare cases, air bubble carpets are also used to reduce the ship's frictional resistance and thus fuel consumption.  

Even less common is the use of wind energy to support the main engines, such as on some Ponant ships. Plans for new ships with wind-assisted systems are still few, with Hurtigruten and Ponant among those planning such ships. 

Somewhat more common in the current fleet, but still rare, is the use of batteries and fuel cells. For example, AIDA Cruises, Havila, Hurtigruten, Hurtigruten Expeditions and Ponant use batteries in some cases. Fuel cells can be found in individual cases, for example at MSC. Some shipping companies are planning to use batteries and fuel cells when converting their ships and placing new orders, but even here, these are not widespread measures. Complete electrification of large cruise ships is currently not feasible due to their high energy requirements. However, batteries and fuel cells can reduce fuel consumption, particularly during manoeuvring, through so-called peak shaving, which allows the main engines to be used less during peak load phases. 

Climate intensity

In general, efficiency measures have reduced energy consumption and thus climate intensity per passenger over the last few years. New ships are becoming increasingly energy-efficient, and retrofits are also being carried out on the existing fleet to increase energy efficiency and thus reduce fuel consumption. The increase in size of individual ships has also contributed to greater efficiency per passenger. 

However, greenhouse gas emissions per passenger and kilometre travelled vary greatly between different shipping companies. Based on available data for the European market (THETIS-MRV), greenhouse gas emissions range from less than 200 to over 900 g CO₂ per passenger kilometre – a difference of more than fourfold depending on the shipping company. 

Alternative Fuels

In order to truly boost the decarbonisation of cruise shipping, in addition to more efficient ships and the increased use of wind assistance, batteries and fuel cells, the most important thing is a shift from the fossil fuels currently in use to renewable fuels, known as efuels or RFNBOs (renewable fuels of non-biological origin). However, this year's cruise ranking shows little progress in the use of efuels. Instead of focusing on technologies that promise true climate neutrality, the industry is predominantly concentrating on LNG (liquefied natural gas) for new orders – a fossil fuel that emits less CO₂, but whose main component, methane, has a greenhouse gas potential more than 80 times greater than CO₂ over a 20-year period.

LNG does not reduce greenhouse gases in either the short or long term but strengthens existing fossil fuel infrastructures and prevents the industry from investing in fuels that enable a real step towards the net-zero climate target by 2050. Even though the availability of eF-fuels such as e-methanol and the corresponding engine technology is still limited at present, it remains unfortunate that there are hardly any concrete measures towards eF-fuels, especially when it comes to new orders. The one positive thing to note is a methanol-capable ship in the existing Mein Schiff fleet. In current newbuild projects, however, there are no truly ambitious pioneers. 

Onshore Power

There is more momentum in decarbonisation during port layovers. Unlike at sea, a ship's energy demand in port can be covered entirely by electricity, ideally from renewable sources, as long as the ship and port are technically equipped. Partly as a result of the EU requirement that large passenger ships must use onshore power in European ports from 2030 onwards, all shipping companies considered in this year's ranking include onshore power-capable ships. Some fleets, such as Havila, Hurtigruten, Hurtigruten Expeditions and Mein Schiff, are already fully equipped, while others are lagging significantly behind and only have a few ships with shore power connections. However, the cruise ranking does not take into account the equally important question of how often ships actually use onshore power in port. While ports such as Hamburg, Kiel and Rostock already offer comprehensive connections for cruise ships, other ports are still a long way from doing so. However, even in ports with charging points, many ships are not yet connected to onshore power. 

End of heavy fuel oil

From NABU's point of view, it is extremely regrettable that only four of the twelve shipping companies analysed reject using heavy fuel oil, which is highly damaging to the environment and climate. Most continue to use toxic but cheap heavy fuel oil. Yet switching to less harmful marine diesel would be technically feasible without any major problems. Instead, many companies rely on heavy fuel oil in combination with exhaust gas cleaning systems (scrubbers), which reduce the sulphur content in the exhaust gas but discharge the resulting residues, enriched with toxic heavy metals and polycyclic aromatic hydrocarbons, into the sea, thus polluting marine ecosystems. 

Nitrogen oxide catalysts and soot emissions

Around half of shipping companies are reducing their nitrogen oxide emissions throughout their fleets, either through exhaust gas aftertreatment systems or the use of cleaner fuels. However, most companies are doing little to address soot emissions. Both nitrogen oxide and soot emissions cause air pollution, posing a particular threat to the health of coastal residents. In addition, soot increases global warming through its black particles, as it absorbs solar radiation instead of reflecting it. This is particularly problematic in Arctic waters, where some of the shipping companies in the cruise ranking also operate: the deposition of soot on ice and snow surfaces reduces their reflectivity and accelerates melting.