Does a seven-day cruise have a personal CO2 footprint of 280 kilograms, or more than 1,500? While some cruises are hardly worse than a vacation in a (small) camper van, others produce as much CO2 as a long-haul flight.
We analyze the real climate impact of cruises and calculate the emissions of specific ships, which the cruise lines themselves do not disclose. And we provide tips on how you can go on a cruise in the most climate-friendly way possible.
Reducing greenhouse gas emissions such as CO2 and methane is a complex challenge. The public discussion about it is typically so trivialized that it is useless, even counterproductive.
Even calculating your personal CO2 footprint for a specific activity such as a cruise is more complicated than you would expect. That’s especially because the necessary facts are simply not publicly available.
Important personal note: This text is an ai-supported, but carefully reviewed version of the text originally published in German language. English is not my mother’s language, so please forgive me if the wording is not always perfect. I’m happy about suggestions for improvement.
But even if you know these figures, you still need data to compare with. Otherwise, it is almost impossible to assess how relatively problematic the respective footprint is. And that’s where it gets really complicated. Especially because the public is constantly comparing data that is not comparable.
Topics in this story:
- The ubiquitous comparison of non-comparable values
- Misconception: if we stopped cruising, the emissions will disappear as well
- Climate impact of cruises: the facts
- CO2 emissions from cruise ships: specific figures
- Personal CO2 footprint: AIDAcosma, AIDAstella, MSC World Europa and MSC Lirica
- CO2 emissions in cruising: graphics, trends and dimensions
- For context: specific figures on CO2 emissions in the travel industry, from flights and motorhome trips
- The allocation problem: Who is responsible for emissions?
- CO2 footprint vs. absolute emissions
- What’s keeping the cruise industry from reducing its CO2e emissions faster?
- Conclusion: How harmful are cruises for the climate?
- Practical tips: How to find the most climate-friendly cruises
- Discuss with us!
The ubiquitous comparison of non-comparable values
And it’s not just about the obvious: that emissions from cruises should not be compared directly with those from airplanes or cars, because a significant portion of emissions from cruises relate to the hotel and entertainment sector, while flying and driving are based only on the actual transportation.
„The climate issue can only be solved by reducing absolute greenhouse gas emissions: to zero, as quickly as possible.“
In most cases, the information as to which emissions are included in the respective figure is missing: Is it only the direct emissions from fuel combustion? Or does it include emissions that arise from the extraction, processing and transport of the fuel? Does the figure only indicate CO2, or is it CO2 equivalents (CO2e), the latter also taking into account powerful greenhouse gases such as methane or nitrous oxide?
In addition to the carbon footprint and comparative data, the topic has a third dimension – and this is actually the most important one: the absolute CO2e emissions. While the carbon footprint helps to estimate one’s own contribution to the climate crisis, it can only be solved by reducing absolute greenhouse gas emissions: to zero, as quickly as possible.
Misconception: if we stopped cruising, the emissions will disappear as well
Public debate looks at cruises in isolation, just like other forms of travel such as flying – and this is misleading. Because when figures are cited, there is always a latent but false assumption: if the cruise ships didn’t exist, the resulting emissions would also be disappear. However, it would be naive to assume that a cruise vacationer who was deprived of the cruise would completely forgo vacation travel.
„Where would cruise vacationers go instead if they couldn’t go on a cruise? And what means of transportation would they use?“
A realistic calculation has to take into account what vacationers would resort to instead: Where would they go on vacation instead, and by what means of transportation? What restaurants and entertainment would they use?
However, this must not be used as an excuse for the fact that, in absolute terms, cruises do cause a significant amount of CO2 emissions. Every gram of CO2 is one too many. But replacing one source of CO2 emissions with another does not solve the problem.
Climate impact of cruises: the facts
When I started researching this article almost a year ago, I thought: well, put a few emission figures on the table and compare them with the CO2 emissions of other forms of vacation, and that will give a good idea of where cruises really stand on this issue.
The sobering result: there are almost no such figures available to the public. And not only in the cruise industry, but also in most other areas of our society and economy. Entire scientific studies admit that they have failed in their attempts to determine real and concrete figures, and resort to averages or well-founded estimates.
„Facts alone often serve only populist arguments. Without their classification and real comparative data, they are not suitable for an objective discussion.“
Of course, this does not stop environmental associations or the media from presenting the figures from such studies as scientifically proven facts and from misusing them for correspondingly false arguments – as populistically and black-and-white as possible.
How big are the CO2 emissions of a long-haul flight? Well, that depends to a large extent on the type of aircraft, among other things. How much greenhouse gas is produced by a motorhome vacation? Even with the same type of motorhome, it depends to a large extent on its equipment and thus on its weight and fuel consumption.
We will see later how many such variables there are in a cruise, which, for example, can easily double or halve the personal footprint of passengers with small changes.
Regarding CO2 emissions: Of course, methane (LNG) must also be taken into account. Methane is much more harmful to the climate than CO2, but it behaves differently: it dissipates into the atmosphere after an average of 12.4 years, while CO2 remains for centuries. Methane is converted into CO2 equivalents (CO2e) for comparability with other greenhouse gases and for the creation of climate models over a period of 20 years (80 times the effect of CO2) or 100 years (28 times the effect).
Neither of the two models fully take in account the today’s effects, which is the crucial factor. The International Maritime Organization (IMO) does not yet include methane in its regulations, and the EU has only started recording methane emissions from shipping since January 2024 (with data being published for the first time in July 2025).
CO2 emissions from cruise ships: specific figures
It is surprisingly difficult to find specific figures for CO2e emissions from cruises – at least ones that are easy to understand and interpret. The sustainability reports of the major cruise lines consistently show absolute emissions in metric tons per year. For 2023, these are:
- Carnival Corp. (92 ships): 9,648,000 mt CO2e
- MSC Cruises (22 ships): 2,640,529 mt CO2
- Norwegian Cruise Line Holdings (32 ships): 3,167,697 mt CO2e
- Royal Caribbean Group (65 ships): 5,375,318 mt CO2e
- al four together (211 of around 350 ships worldwide): 20,831,544 mt CO2e – around 20.8 million metric tons
The figures given refer to Scope 1 and 2, but include not only CO2 (as do the values from the EU database further below in the article), but also methane (except for MSC Cruises, where only CO2 is mentioned).
For context: In its comprehensive GHG Study 2020, the International Maritime Organization (IMO) determined that in 2018, the entire shipping industry emitted 1,076 million tons of CO2e, and that the trend is clearly rising. In relation to the total global emissions of 36,573 million tons, this is about 2.89 percent.
How many ships are there worldwide?
The IMO GHG Study also provides information on the number of ships worldwide, also based on the year 2018:
- cargo/container/tanker ships: almost 50,000 (41 percent of all ships)
- other ships (offshore, tugboats, fishing, yachts): 61,000 (51 percent)
- ferries including Ro-Ro: 8,000 (7.2 percent)
- cruise ships: 600 (0.5 percent)
„The cruise industry’s share of global CO2 emissions is less than 0.1 percent.“
With regard to emissions, it should be noted that the cruise industry’s share is disproportionately high. OECD figures (recorded in the first quarter of 2023) show that the cruise industry’s share of emissions from shipping is 3.1 percent. The reason for this is the energy required by cruise ships for hotel and entertainment operations. In terms of global emissions, this results in a cruise share of 0.09 percent.
Complete emissions figures for individual ships not publicly available
The figures would be much more readily understandable if they were based on individual cruise ships. Above all, this would also allow to distinguish between different ships. However, it is precisely these figures that are not fully available to the public. We can only speculate as to why the cruise lines are not forthcoming with the figures.
„There is a lack of specific and standardized comparable emissions figures for specific cruise ships.“
One important reason, as our research suggests, is the negative attitude of many media and NGOs towards cruises. Any specific figure, how relatively positive it may ever be, would be immediately used by these groups against the respective cruise line. So the cruise lines prefer to remain silent in order to avoid voluntarily putting themselves in the focus of anti-cruise campaigns.
What can be calculated from the available figures is a cruise line-specific or industry-wide average that can be imagined: the “footprint” of a cruise per passenger. How much CO2 emissions is a passenger responsible for on a seven-day cruise?
Personal CO2 footprint of a cruise at the industry average
Prof. Andreas Humpe from Munich University of Applied Sciences (“Hochschule München”) calculates 827 kilograms for an average cruise of 7.2 days in 2019. Our own calculations for a seven-day cruise yield a slightly lower value of 796 kilograms, but the dimension of around 800 kilograms is roughly the same. (Both calculations refer to Scope 1 and 2 – for more details, see the chapter „Allocation problem“).
„Industry averages reflect the state of technical development from around 15 years ago.“
The issue with this figure, however, is that it reflects the state of technology from around 15 years ago. This is because the average value also includes cruise ships that were built 30 or more years ago. However, ships built today only cause a fraction of emissions per passenger due to technical progress.
So if you want to know your carbon footprint on a brand-new cruise ship, this figure is of no use. If you want to know where cruising stands today, you need different figures.
Personal CO2 footprint on a new cruise ship
I spent a large part of my research on this chapter – and yet the result is only a rough guideline. This is because figures for the CO2 footprint on specific cruise ships simply do not exist and cannot be easily calculated from publicly available data.
„The EU collects and publishes valuable data on ship emissions. But of all things, one essential figure is missing…“
Nevertheless, I was able to determine reasonably precise figures for some ships. An important source for this is the European Union’s THETIS database, which is based on the MRV system. For several years now, EU shipping companies, including cruise lines, have been required to report their emissions figures and have them independently verified.
However, one essential value is missing from this database: how much time did a ship spend in ports. Thus, the information on how much CO2 the ship emitted during port calls is largely useless but would be crucial for calculating the footprint.
I therefore searched for data on the port call times of individual cruise ships, including by evaluating catalogs from 2023, to determine the missing piece of the puzzle in the EU database. These figures are – likely quite precise – approximations, but I am unable to determine whether the ships actually always arrived and departed at the scheduled time.
„Methane slip is not taken into account (so far).”“
It should also be noted that AIDAcosma, Costa Smeralda and MSC World Europa use LNG as fuel, which emits a good 20 percent less CO2 than heavy fuel oil or marine diesel when combusted. This does, however, result in a certain methane slip – but this has not yet been recorded in the EU database for 2023.
From 2024, the climate impact of methane will also be taken into account. However, since there is still no standardized measurement method for methane emissions, shipping companies will initially have to set a calculated value for it, which, while bringing more comparability of the climate impact of different fuels, has little informative value about the actual methane slip of the specific ship.
Personal CO2 footprint: AIDAcosma, AIDAstella, MSC World Europa and MSC Lirica
ship | year | tonnage (GT) | passengers (lower berths) | GT per passenger | CO2 per passenger per week in kg |
AIDAcosma (LNG) | 2021 | 183.774 | 5.252 | 35,0 | 280 |
AIDAstella | 2013 | 71.304 | 2.194 | 32,5 | 457 |
MSC World Europa (LNG) | 2022 | 215.863 | 5.264 | 41,0 | 412 |
MSC Lirica | 2003 | 65.591 | 1.984 | 31,1 | 617 |
Mein Schiff 4 | 2015 | 99.526 | 2.506 | 39,7 | 546 |
Costa Smeralda (LNG) | 2019 | 185.010 | 5.224 | 35,4 | 279 |
Symphony of the Seas | 2018 | 228.081 | 5.518 | 41,3 | 539 |
Norwegian Prima | 2022 | 143.535 | 3.099 | 46,3 | 822 |
average of all ships | 2011 | 80.930 | 1.990 | 40,7 | 765 * |
*The average figure weighted by the number of passengers is based, unlike the values for the specific ships, on projections and estimates regarding the time in port and is therefore only an approximate guideline.
Please note: The CO2 values in the table do not represent a ranking because the data cannot be directly compared due to different fuels (see above) and different destinations and routes. The figures merely show a snapshot of the ships‘ actual operations during the European seasons of 2023, which also varied considerably in length.
AIDAcosma, Costa Smeralda and MSC World Europa each sailed predominantly very similar routes in the western Mediterranean in 2023, albeit covering very different distances, which partly explains the relatively significant difference in their respective footprint figures. The route of MSC World Europa was about 1,700 miles, that of Costa Smeralda 1,480 miles, and that of AIDAcosma around 1,200 miles. We estimated the distances via sea-distances.org.
Norwegian Prima is a good example of how a more luxurious passenger-to-space ratio can have a negative impact on personal footprints, even on a brand-new ship. In addition, the Norwegian Prima has covered relatively long distances in parts of its 2023 European season.
The relatively good space-passenger ratio also has an impact on the personal CO2 footprint for Mein Schiff 4 and Symphony of the Seas. In addition, the Royal Caribbean ship covered a longer distance than the AIDAcosma in the same area, with around 1,500 miles in the Mediterranean over the entire summer. In 2023, Mein Schiff 4 sailed a mix of medium-range routes in the Canary Islands with Madeira and Morocco, as well as long routes in Norway.
What is surprising at first glance is that even older cruise ships (with crude-oil-based fuels) can have a relatively low footprint compared to the industry average, as we have calculated for AIDAstella or MSC Lirica, for example. Due to the wide variety of routes, the distances traveled by these two ships cannot be determined in a reliable way. However, the relatively low figures can most likely be explained by shorter distances and lower speeds, which reduce fuel consumption.
But there are also spikes in the other direction: figures beyond 1,500 kg per passenger per week up to a single ship with an extreme value of around 5,000. Such values occur in particular (but by no means in every case) in smaller or older luxury ships with few passengers in relation to tonnage. I am deliberately refraining from naming such ships here, because I can only make very rough estimates without knowing the respective times spent in ports – and such figures for a specific ship could therefore be far from reality.
CO2 emissions in cruising: graphics, trends and dimensions
Some graphics based on the figures from the EU database show trends and fundamental relationships. However, these graphics also show that the personal CO2 footprint for cruise ship passengers depends to a large extent on factors other than just the year of construction and the typically associated better energy efficiency.
In particular, low cruising speed, short distances and the duration of port calls can also lead to a lower footprint for an older, less efficient ship than for a brand-new ship traveling long distances at high speeds.
CO2 emissions per passenger and distance in relation to the year of launch of the ships
A relation to the year of launch of the ships is clearly recognizable when looking at the premium and mass markets, i.e. ships with more than 1,000 passengers. On average, the newer the cruise ship, the lower its carbon footprint.
When the smaller ships are included, the picture changes and the average value deteriorates again from around 2010:
CO2 emissions in kilograms from all cruise ships in relation to the year of construction
If you look at which ships are causing the spikes here, they are luxurious, small ships that have launched in recent years. Although these ships are highly efficient from a technical point of view, the low number of passengers per tonnage thoroughly spoils their climate footprint.
Average speed in relation to the age of the ship
It is particularly interesting to note the speeds at which the cruise lines operate their ships in relation to their year of launch and their energy efficiency (and thus also fuel costs).
The very old ships with particularly high fuel consumption, which increases exponentially at higher speeds, deliberately travel more slowly. The middle-aged ships, which were optimized at construction for higher speeds of over 20 knots, tend to travel faster. They are more efficient, so higher costs do not have such a significant impact.
By contrast, the newest cruise ships are usually optimized for lower cruising speeds and are also more energy efficient, which results in a dip in the graph and thus a lower footprint.
The following graphic only takes into account ships with fewer than 1,000 passengers, i.e. mainly from the luxury segment. It is quite clear that some cruise lines travel at very low speeds, thereby compensating for their lower efficiency and/or the disadvantages of the unfavorable ratio of passenger counts to tonnage. Ponant stands out particularly positively here, but so do Windstar and Hapag-Lloyd Cruises, for example.
The bigger, the worse? CO2 per passenger and nautical mile in relation to tonnage
One prejudice that you read about cruises again and again is that the bigger the ship, the worse it is. In terms of absolute emissions, that is of course true. When it comes to the individual footprint, however, the opposite tends to be true: the bigger, the better, or rather, the lower.
The following graphic shows the CO2 emissions per passenger and nautical mile in grams and in relation to the gross tonnage of the respective ship in 2023 within the EU. To keep the graphic clear, we have reduced the number of ships and, for example, included only one ship from each ship class
In the following graphic, we look at the same statistics again, but this time only with cruise ships from German shipping companies.
It is important to understand that both graphics are snapshots for 2023 depending on the routes taken and not a general classification of the climate friendliness of the ships listed – which can be clearly seen from the one or other supposed spike in the graph.
For context: specific figures on CO2 emissions in the travel industry, from flights and motorhome trips
I don’t want to dwell on the comparison of cruises with other forms of travel. This is because a direct comparison is almost impossible because the aspects to be considered are so variable and ultimately arbitrary that you can prove just about anything with such statistics, and yet you can’t get any closer to reality.
Nevertheless, I would like to present a few rough figures so that a cruise can at least be roughly classified. Above all, however, the figures should show that the cruise is often wrongly demonized – as if it were the only form of vacation (besides flying, which is somehow taken for granted) that is problematic in terms of climate change.
Also noteworthy for the classification of cruises is an estimate made by the World Travel & Tourism Council in cooperation with the United Nations using 2019 figures. The 2021 report “A Net Zero Roadmap für Travel & Tourism” shows the shares of different industries and sectors in the CO2 emissions of the entire travel sector worldwide. The following graphic is based on these figures (excluding Scope 3, for which there were still too few figures in 2019).
Tourism-related greenhouse gas emissions by industry, 2019
Note: The percentages in the source add up to less than 100 percent, which is why I added the missing 1.4 percentage points to the figure for “other”.
Aviation, motorhomes, heating at home
It should be noted that the figures already mentioned for cruises refer to the entire trip, including hotel services (especially air conditioning) and entertainment on board, while the following figures only include the pure transportation service.
It should also be noted that the figures given – especially in the absence of further data – only take into account direct emissions (Scope 1).
For a return trip by two people in a campervan from Frankfurt to Rimini and back (roughly 1,000 kilometers, or 620 miles one-way), the CO2 footprint for fuel consumption is 193 kilograms per person.
Base model of the most popular motoehome in Germany (and very small compared to what people use in the US), Fiat Ducato (Ducato L1H1 250.0K1.0 Diesel, 100 hp), fuel consumption 7.1 liters per 100 kilometers, CO2 emissions: 193 grams per kilometer according to mobile.de. We do not take into account that the Fiat Ducato, converted into a camper, is likely to consume more than 10 liters.
According to My Climate, aa return flight from Munich to Mallorca (roughly 780 kilometers, or 485 miles one-way) can result in a carbon footprint of around 500 kilograms per passenger, depending on the aircraft type. For a long-haul flight from Munich to Bangkok and back (roughly 5,500 kilometer, or 3,400 miles one-way), the figure is 2,700 to 3,900 kilograms, again depending on the aircraft type.
And how large is the CO2 footprint at home for heating with natural gas (which is pretty common in Germany)? An average two-person apartment with 90 square meters of living space has a gas consumption of 12,600 kWh, 1,260 cubic meters of natural gas per year. Converted to a seven-day period, which is the reference period for a cruise, this results in a CO2 footprint of 24.3 kilograms per person. Calculation of the CO2 numbers according to Go Climate: 201 g CO2 / kWhPE.
Important factor: How do you travel to your holiday destination?
For such comparisons, there is an important aspect that should reasonably be taken into account: the journey to the holiday destination or the embarkation port of the ship. Regardless of the type of vacation, the traveler’s individual climate balance deteriorates considerably when traveling by plane – the further the flight, the more significant the impact.
In this context, the cruise is always assumed to be traveling by plane – with correspondingly poor overall values. But that often does not do justice to the matter. For example, at AIDA, on average only around 50 percent of passengers arrive by plane, and in the summer the figure is even lower, at just 20 to 30 percent, because the ships then mainly depart from German ports, so that passengers predominantly travel by car, bus or train. The figures come from AIDA Cruises itself.
The allocation problem: Who is responsible for emissions?
It sounds trivial, but it is a major challenge: To whom do you allocate greenhouse gas emissions? In other words, who is responsible for preventing the respective emissions?
The Greenhouse Gas Protocol has been established to classify greenhouse gas emissions, distinguishing between three levels, referred to as “scopes”.
Scope 1: Emissions for which the company is directly responsible and which it can control. During a cruise, around 99 percent of these emissions come from the fuel used.
Scope 2: Emissions from purchased energy such as electricity that is generated outside the company but used by it. During a cruise, these emissions are mainly produced in the offices and cruise terminals on land, but increasingly also through the use of shore power.
Scope 3: Almost half of the emissions in the cruise sector are attributable to purchased goods (food, beverages, ship equipment) and services, as well as to a large extent to capital goods (in particular the construction of the ships in the shipyard) and aspects related to fuels and energy (extraction/production, processing, provision).
Scope 2 emissions are very low for cruises and therefore hardly relevant. By contrast, Scope 1 and 3 are almost equal in magnitude (between 56:44 percent and 50:50 percent according to the sustainability reports of the cruise lines), which means that in this industry it is crucial to whom the Scope 3 emissions are assigned.
„Capturing scope 3 emissions is a Sisyphean task. Even with a great deal of effort, companies usually have to rely on estimates and projections.“
Scope 3 is quite difficult to deal with, not only in the cruise industry. On the one hand, calculating emissions in this segment is very complex because numerous companies and states with different regulations are involved in the value chain. There is no way avoiding estimates here.
On the other hand, the allocation entails various disadvantages and incentives: if you allocate emissions to the producer, there is little incentive for the consumer to reduce the emissions. If you allocate them to the consumer, there is at best only indirect pressure on the producer, through market competition, to make the product more climate-friendly.
„For the use of fuels for cruise ships, though net-zero, still containing carbon, so scope 3 emissions must be included.“
At first glance, it may come as a surprise: the cruise industry explicitly wants to take responsibility for scope 3 emissions as well. If we look at the foreseeable alternative fuels, there is a good reason for this: CO2 is also produced during the combustion of the essential e- and bio-fuels of the future. These fuels only become climate-neutral when taking in account their production, and thus scope 3.
The big, publicly listed cruise companies Carnival Corp., Royal Caribbean Group und Norwegian Cruise Line Holdings, but not yet the privately held MSC Cruises, have been reporting scope 3 emissions in their sustainability reports since the 2023 reporting year at the latest.
In its sustainability report 2023, TUI Cruises provides a comparative analysis of tank-to-wake (scope 1) and well-to-wake calculations (including scope 3) specifically in relation to fuel. Here, the well-to-wake value is about 22 percent higher than the tank-to-wake value. Specifically, these total emissions from TUI Cruises in 2023 are 573,933.76 and 704,401.92 metric tons of CO2e, respectively.
CO2 footprint vs. absolute emissions
To be honest, I spent way too much time in this article looking only at the personal CO2 footprint. This is because it is actually not relevant for stopping climate change. This applies to all areas of life, not just to the cruise sector, and it is the biggest challenge in the climate discussion.
It is legitimate and important to look at the CO2e per passenger in order to better assess one’s personal footprint. But the individual footprint is not suitable as a global benchmark.
The only thing that counts is that the absolute value of total global CO2e emissions must be reduced as quickly as possible and reach zero quickly.
Each individual can contribute to this by keeping their own personal footprint as low as possible. But one essential requirement on this path initially sounds radical: companies must only be allowed to grow in a climate-neutral way. In terms of the cruises industry, this means that any cruise line that wants to put a new cruise ship into service can only do so if the cruise line’s total CO2e emissions remain the same at most, but ideally decrease at the same time.
Incidentally, this is not a utopian demand by radical pro-climate activists. Even managers in the cruise industry, such as Lucienne Damm, TUI Cruises‘ Head of Sustainability, say so to Cruisetricks.de: “The absolute reduction must be the goal. Anything else, in my opinion, is window dressing. Because then I’m living in an old world. That’s why TUI Cruises has committed to an absolute emissions reduction target despite three new ships in the years 2024 to 2026, which has been verified by the Science Based Targets Initiative (SBTi),“ she says.
Lucienne Damm adds: ”At the moment, we don’t yet have, or don’t have enough of, many technologies and fuels that could help us decouple growth from carbon emissions. But that is precisely the task we have as a company – especially as a travel company, and particularly as a cruise line. Sustainable responsibility means we are growing and have a plan that shows exactly that.“
What’s keeping the cruise industry from reducing its CO2e emissions faster?
If we take a closer look at the question of why cruise ships are not reducing emissions faster, we quickly end up pulling your hair out when faced with the facts: once again, it’s quite complicated. Above all, however, you regularly hear from those in charge of cruise ships: “We would like to, but…” Because regulations and rules often don’t make technical progress as easy as one would like.
Nick Rose, Vice President Environmental, Social and Governance of the Royal Caribbbean Group, puts it in a cruisetricks.de interview like this: “Talking generally about global regulations, many want things to be 100 percent perfect from day one and that is actually a detriment to technology advancement. So that’s where I think one has to push the other. But it can’t be so far gapped that it actually disincentivizes people from taking leaps.“
There is a conflict between technical development, regulations, investment reliability and the long time frames in which this takes place, while a bigger time frame for climate protection is potentially no longer available.
Because this is a separate and extensive topic, I have only summarized the main aspects here in bullet points:
- The long lifespan of cruise ships of around 30 years: The technology available at the time of planning and construction of the ship is crucial. However, e-fuels and biofuels, for example, also offer options for existing ships.
- Climate-neutral solutions for cruise ships are emerging, but they are not yet technically mature enough to be operational.
- Even if they are operational, the necessary regulations are often still missing. Shipyards and cruise lines can only use technology that is accepted by the authorities if they don’t want to risk building a ship that may not be allowed to sail.
- A sufficient availability of alternative fuels is difficult to estimate and makes the decision for a certain technology a risk factor.
- The regulatory framework for alternative fuels is (still) inadequate. Current regulations such as the IMO’s mandatory energy efficiency limits for the EEDI (Energy Efficiency Design Index) and CII (Carbon Intensity Indicator) tend to discourage the use of e-fuels and biofuels due to their calculation method. Furthermore, the indices have been developed for the entire shipping industry, which means that cruise ships are subject to contradictory consequences. For example, long port stays and slow cruising speeds lead to disadvantages when calculating the CII. (IMO is about to address this for the cruise industry, though, see MEPC82).
- Current regulations, in particular those of the IMO, are based on the tank-to-wake principle: the CO2 emissions from fuel combustion are what count. However, from a climate perspective and for the sensible use of fuels from renewable sources, only the well-to-wake principle, which takes into account the entire value chain, is expedient. Even adjustment factors for biofuels only change this to a limited extent. The problem has been recognized, but changes at IMO level require agreement among 175 member states – and that takes time.
Gijs Streppel, Program Manager Sustainability at Meyer Group, comments: „It is very difficult to develop a future-oriented design because a truly future-oriented design does not meet today’s regulations. As with LNG, we first have to develop these together. Because if I were to switch to renewable fuels that contain carbon, such as e-methanol, then they have no advantage (with the tank-to-wake approach). So I can’t currently design ships that are greener than those based on LNG. This is because all the options currently available for cruise ships that are based on E or biofuels contain carbon.“
The cruise industry is increasingly responding to this problem with a relatively expensive and elaborate compromise that keeps as many doors open as possible: engines prepared for methanol operation, dual- or even tri-fuel engines (Celebrity Xcel, 2025). These engines are capable of using both – primarily – LNG and alternatively marine diesel with the prospect of switching to climate-friendly or climate-neutral e- and bio-fuels as well as (green) methanol.
The European Union is already providing the right regulatory impulses. Since 2024, shipping and thus also cruises have been part of the emissions trading scheme ETS. This is a proven and effective means of steadily reducing CO2 emissions from other sectors. However, the methodology of the ETS requirements is currently still somewhat at odds with the EEDI and CII indices mentioned above.
Lucienne Damm of TUI Cruises welcomes the inclusion of cruises in the EU’s emissions trading scheme: “This means that fossil fuels are becoming less and less attractive in principle, while the others are becoming more attractive commercially. They are not yet at the same level, though. They are still much more expensive.”
Emissions trading does not aim at a relative reduction in emissions per passenger, but at the absolute amount of CO2 (and methane from 2026). And because CO2 emissions are given a specific price, the cost calculation for the shipping companies is precise and can be planned. In addition, ETS is a system that is easy to understand and follow, even for non-technicians.
Conclusion: How harmful are cruises for the climate?
I’m aware of the fact that the length of this article is a challenge for my readers, but if you seriously want to explore how climate-damaging cruises are, a few simple buzzwords, a few figures taken out of context, and a few prejudiced platitudes are not enough.
How climate-damaging is cruising? The question itself is wrong. Our entire society is harmful to the climate as long as it emits greenhouse gases. Cruising is a small part of this. Which path do we want to take to reduce global greenhouse gas emissions to zero? Do we want to do this at all? Seriously, not just as lip service and to ease our conscience?
How harmful to the climate is a cruise? It’s the right question if you are looking for a convenient bogeyman to avoid having to deal with climate protection. Because as a scape goat, the cruise is particularly suitable because it is supposedly superfluous as a leisure activity and prejudices about cruising are supposedly common knowledge.
On top of that, cruising has the – no longer accurate – aura of luxury only for the rich. This is actually a left-wing political perspective, but surprisingly it is also adopted by people with a more conservative view. The reason for this is perhaps that it is easy to point the finger at the ships because hardly anyone would be affected by restrictions on cruising – after all, ocean cruises currently account for only an estimated five percent of the German travel market (for reference, see DRV), and similar in the US. Incidentally, at 9.3 percent, the share of long-haul travel is almost twice as high.
How harmful are cruises for the climate? Depending on the ideological background and the scale of consideration, the answer varies greatly. Which of these standards we apply depends on our decision on how we want to deal with global warming in principle.
I neither want nor can I make this decision for society here. But in this article, I have tried to present facts and contexts that help to place the cruise in our overall system and to draw the right conclusions from it.
Practical tips: How to find the most climate-friendly cruises
On a personal level, there are many aspects that can make a cruise relatively climate-friendly – not in absolute terms, but in relation to other forms of vacation. The following aspects are not guarantees, but they do indicate a comparatively low personal CO2e footprint:
- Travel to and from the cruise ship by train or bus, if necessary by car, but in any case if possible not by plane.
- large, modern cruise ship with high passenger density
- long layovers in port
- short distances and resulting potentially low speeds
- better once a year a longer than several times a shorter vacation reduces emissions from travel.
Even if the EU database THETIS with its extensive but unfortunately incomplete data does not allow a concrete calculation of the footprint per passenger for individual ships, some trends can be identified:
A new ship that only travels short distances at low speed will typically beat an older ship that behaves the same way. However, not all large ships ae being operated in this way.
Large ships tend to be more efficient – although not as much as one would assume based on technical energy efficiency. This is because very large ships have a higher energy demand per passenger in port, presumably due to the more elaborate hotel and entertainment operations. Very small ships, on the other hand, reduce both their relative (per passenger) and absolute energy consumption in port quite considerably.
Discuss with us!
I hope to learn from your comments about how well I perform in presenting the complex topic of the climate impact of cruising in an objective, non-ideological and easy to understand way. I look forward to reading your opinions!