Year after year, cruise ships get bigger, more elaborate, and more fanciful; but does the carbon footprint of cruise ships put a damper on the fun?
As modern cruise ships have grown to be ever more massive and imposing, the level of their emissions has kept pace.
But just how severe is their impact on the climate?
Unfortunately, taking a cruise takes a toll on the planet. Your trip will average anywhere from 700-1000 pounds of carbon emissions a day, which is much higher than flying, driving or a traditional ‘land’ vacation.
This guide explains how the carbon footprint of cruise ships is calculated, both by location and miles, and some things that you can do to mitigate the emissions if you take a cruise.
Ocean Liner vs Passenger Cruise Ship: What’s the Difference?
If you want to properly understand the carbon footprint of cruise ships, it’s important to make sure you have accurate definitions for all the key concepts involved in the discussion. An important distinction to make sure you can articulate is the difference between cruise ships and ocean liners.
While both types of vessels are large passenger ships traversing the world’s oceans, there are a number of key distinctions that influence both their environmental impact and the significance of that impact.
Ocean Liner vs Cruise Ship: Purpose
The first and most clearly delineated difference between cruise ships and ocean liners is their intended use. Ocean liners’ primary purpose is to take people on long-distance journeys from one port to another.
Some examples of ocean liners you are most likely to be familiar with are the Queen Mary, the Lusitania, and, of course, the RMS Titanic, whose route ran from Southampton in the United Kingdom to New York in the United States.
As air travel became cheaper, more widely available, and more cost-effective, ocean liners became largely obsolete. At the time of this writing in 2023, if you want to voyage on an ocean liner, you’ll need to book a berth aboard the Queen Mary II, as it is the last ocean liner still in service.
If you’re looking for a cruise ship, odds are good that you’re more interested in tourism and recreation than moving from one continent to another.
When you board a cruise ship, you’re most likely going to disembark at the same place you boarded; the modern tourism economy favors shorter trips to a number of ports in the same region over an extended voyage between continents.
Ocean Liner vs Cruise Ship: Design
Given the development of air travel, you can understand how cruises would be a natural evolution for ocean liners, and indeed ocean liners served as the first cruise ships and still inform the design of many modern cruise ships. However, ocean liners are held to higher speed and construction standards, so cruise ship lines have moved away from offering that service in order to save money.
Because ocean liners’ primary purpose is transporting people and goods from point A to point B across the open ocean, ocean liners were built with thicker hulls, resting lower in the water in order to improve stability, and narrower, more aerodynamic shapes in order to maximize speed. In order to promote safety even in heavy seas, ocean liners typically have decks placed higher in the overall structure of the ship.
Cruise ships, being primarily recreational in purpose and typically taking much shorter journeys between ports, are constructed with more focus on your enjoyment as a guest than your swift conveyance across the Atlantic. Reserving the sections of the ship that are below the waterline exclusively for non-passenger-facing areas, much more of the ship rests above the waterline.
Additionally, in order to provide guests with more opportunities out in the open air, cruise ships’ decks are often much lower than they would be on an ocean liner. While this does leave cruise ships more vulnerable to weather, they are usually not in open water conditions where this weakness is a significant factor.
Ocean Liner vs Cruise Ship: Operations
Another area where you will see a significant difference between ocean liners and cruise ships is in the manner in which they are operated.
Because ocean liners are transports first and foremost, they tend to prioritize getting to the destination on time over optimal comfort and conditions on board.
This can lead to a rough voyage for you as a passenger if the weather and sea conditions are bad, but it means you’ll be more likely to arrive on time at your destination.
On the other hand, if you’re on a cruise ship, speed is not a priority. Cruise ships tend to favor holding a steady pace and ensuring guest comfort onboard over speed.
While both types of vessels may have onboard recreation opportunities for passengers, cruise ships are more focused on ensuring the guests are able to make full use of as many of the amenities as possible. Activities aboard the ship are often more central to a cruise ship’s operation than reaching the destination.
| Ocean Liner | Cruise Ship | |
| Purpose | Transportation across the open ocean | Tourism and recreation within a region |
| Priority | Speed and Safety | Recreation and Comfort |
| Hull | Extra thick | Standard thickness |
| Waterline | Higher for stability | Lower for comfort |
Cruise Ships’ Environmental Impact: Are Cruises Bad for the Environment?
All you need to do is look at modern cruise liners, with their towering hulls, and you can begin to figure out that they probably generate a lot of pollution. According to Wikipedia,10 cruise ships both generate air pollution from burning fuel and pose substantial water pollution from the variety of products used in the maintenance of the ships and created by their passengers.
Your average cruise ship runs on high-sulfur heavy fuel oil, which leads to them emitting considerably more sulfur dioxide than an equivalent number of cars. Because fuel is used both to move the ship and to power the countless shipboard systems, cruise ships are constantly burning it, even when docked.
Calculating Carbon Emissions
Any discussion you’ve ever been a part of about climate change and environmental damage has probably centered on carbon emissions, and the carbon footprint of cruise ships is definitely worth considering when planning your vacation. While carbon footprint is a phrase you have likely heard before, you may be less familiar with what that phrase actually means or how carbon footprint calculation is done.
So what is a carbon footprint? According to the University of Michigan,11 a carbon footprint is the sum total of all the greenhouse gases emitted by something.
This would include both the emissions of the person, organization, or event, and any greenhouse gas emissions created in every phase of its lifespan. This measurement can be made using a carbon emissions calculator.
If you have ever wanted to learn how to calculate carbon footprint manually, you need to know your monthly electric, gas, and oil bills, your mileage traveled by car and plane, and your own access to recycling programs. Once you have these pieces of data, you can generate a rough estimate of your carbon footprint.
If you don’t have access to or want to use such specific data, or are only aware of general trends in your behavior, there are ecological footprint calculators that you can use to get an idea of your own emissions.
It’s not uncommon that, when you plug your information into one of these footprint calculators, the total you’re faced with when the numbers have all been crunched may be concerning. It would be entirely understandable that you would want to do whatever you can to reduce your carbon footprint.
Georgetown University has a number of small, easy-to-manage steps you can take to bring down your carbon footprint.12 Using more efficient electronics and being proactive about not wasting power usage in your home can be very effective ways to reduce your carbon footprint, but even then you’re simply doing less damage, not actively repairing the environment.
The most straightforward way you can actively reduce the amount of carbon already in the air is by planting trees. Trees are naturally occurring carbon sinks, absorbing greenhouse gases like carbon dioxide from the air and processing them to turn them into oxygen.
Planting trees can be a big step toward undoing our negative impact on the environment, but because trees take decades to grow it’s important to be aggressive and proactive in planting trees now so that they can continue to grow, develop, and combat climate change.
Cruise Ship Carbon Emissions: Carbon Footprint of Cruise Ships
If you’re planning a vacation, it can also be understandable to want your trip to have as little environmental impact as possible. This may also guide how you plan to travel: knowing the impact on your carbon footprint driving vs flying can have will help you make the best choice possible in how to travel.
The simplest, most direct way you can figure this out is with a travel carbon footprint calculator.
Naturally, driving generates more carbon than walking or biking, and flying has a larger carbon footprint than driving does. However, not only does taking a cruise ship have a carbon footprint of 3 times as much as flying for the same distance and number of passengers, but cruise ships also emit a number of uniquely toxic chemicals due to the fuel they use.
This has led to a number of government agencies having to reconfigure how they will regulate cruise ships in sensitive environments, as exemplified by the National Park Service and their work to protect sensitive Arctic environments from the negative consequences of cruise ships.13
What Do Cruise Ships Run On?
As you read above, most cruise ships run on heavy fuel oil. Heavy fuel oils are a byproduct of distilling petroleum and are contaminated with a number of other chemicals like sulfur and nitrogen.1
These contaminants make heavy fuel oil a lower-cost fuel than other alternatives, which makes it a common fuel choice for marine vessels given the sheer volume of fuel consumed by such large machines.
Heavy fuel oil has a thick, tar-like consistency, so in situations where it spills, you are likely to see it coating the fur or feathers of wildlife in the region in a thick layer that can be difficult to remove. This can lead to significant environmental damage at a number of different levels of the ecosystem.
Depending on your cruise, the carbon footprint for each passenger, when all the emissions are totaled from fuel, operations (food, entertainment, etc.) and everything amounts to approximately 661 pounds of carbon emissions a day, per person.
Various factors can increase that amount, and most studies suggest that on average, the total footprint for a cruise passenger is approximately 900 pounds per day.
Mitigating Fuel Emissions
Given the significant drawbacks of heavy fuel oil, cruise companies have begun experimenting with alternative fuels. Carnival, the world’s largest cruise company responsible for around 45% of the world’s cruise ships, currently operates 8 ships that run on liquified natural gas.2
Liquified natural gas is generally considered to be the fossil fuel with the least negative impact on the environment. It is used in a liquid form instead of as a gas because the liquid form takes up 600 times less space than the gaseous form does.
The gas is typically liquified by means of refrigeration, which does require specialized equipment in order to get it down to a temperature of -260 degrees Fahrenheit.
Liquified natural gas emits 99% less sulfur and 30% less overall greenhouse emissions than heavy fuel oil. This would be a marked improvement in air pollution for regions like Europe, where in 2022 cruise ships created 4.4 times as much air pollution as all the cars in the region combined.3
The drawbacks of LNG are that there is a higher initial cost to build ships running on it than HFO because it requires a different engine design (this also means that existing ships cannot easily be converted) and that currently LNG fueling depots are relatively uncommon, although this will likely be less of an issue as time goes on if LNG continues to be adopted.
Additionally, natural gas is still a fossil fuel, which means that it is finite and may exhaust the supply of it.
Another alternative fuel beginning to be used is biofuel, made from a mix of waste vegetable and cooking oils, animal fat, and corn. One major advantage of biofuel is that it can be produced quickly, whereas fossil fuels are created on a geological time scale.
Another is that it is chemically similar enough to diesel fuel to be used in its place, without needing to build new specialized ships. Additionally, they produce significantly fewer emissions than fossil fuels, according to the US Energy Information Administration.14
However, biofuels aren’t a one-size-fits-all solution either. You may know that at the present time, producing biofuels has a high cost, which can drive prices up and disincentivize their use.
Additionally, depending on how the crops processed into biofuel are grown, there may still be a significant quantity of emissions involved in the production process. Biofuels are also less efficient than fossil fuels, meaning that you need a larger volume of biofuel in order to travel the same distance.
Eco-Friendly Cruise Ships Operated by the Three Largest Companies
The table below shows the number of cruise ships currently operating to give a sense of scale. These figures refer to the three largest cruise companies in the industry, which collectively comprise more than 70% of the industry overall.
This provides context for the data on how much an individual cruise ship pollutes, which helps make sense of how what may seem at first to be a niche industry can have such a disproportionate impact on the environment. Given that even a medium-sized cruise ship can have worse emissions than thousands of cars, multiplying the pollution created by one ship to reflect the broader industry paints a bleak picture of their impact on the environment.6
| Cruise Company | Annual Passengers (Thousands) | Total Fleet (in Ships) | Ships Using LNG | Ships Using Biofuels |
| Carnival Corporation | 5,842.6 | 91 4 | 11 (6 currently, 5 expected by 2025) | 1 |
| Royal Caribbean Group | 3,278.5 | 63 5 | 4 (0 currently, 4 expected by 2026) | 2 |
| Norwegian Cruise Line Holdings | 1,319.9 | 29 | 0 (investigating using methanol instead of LNG) | 2 |
Carbon Footprint of Cruise Ships: How Much Pollution Do Cruise Ships Produce?
In order to understand the scope of the pollution produced by cruise ships, you need to comprehend how much pollution is created by an average cruise ship, and the breakdown of how much pollution is created per passenger when compared to alternative modes of travel.
According to the Department of Transportation’s Bureau of Transportation Statistics,15 over the course of a week-long voyage a cruise ship generates qualities of waste that may boggle your mind. 210,000 gallons of sewage, a million gallons of gray water, 130 gallons of hazardous waste, 16 tons of solid waste (much of which may be burned and converted into air pollution), and 25,000 gallons of oily bilge water.
(Image: Jürgen Sieber22)
These can all pose a severe threat to marine ecosystems when they are dumped.
The picture gets even more grim when air pollution is considered as well. A single cruise ship can produce 450 kg of ultrafine airborne particles and five tons of nitrogen oxide emissions in a single day. These chemicals are carcinogenic, as are sulfur oxides, of which a single large cruise ship produces as much as 3.6 million cars.
This poses a very real risk for passengers; one study found that, on some cruise ships, the air on the top deck can be more densely packed with ultra-fine particulates than the air in cities like Shanghai and Delhi, which regularly feature on lists of cities with the worst air quality in the world.7
It could be argued that, while cruise ships do produce massive pollution, they carry so many people that it balances out. Unfortunately, the research doesn’t support that argument.
In terms of carbon dioxide production, each day you spend as an individual passenger on a cruise ship generates approximately 420 kilograms of carbon dioxide per day.
At the same time, if you choose a high-end hotel and take high-carbon transportation to activities with a high level of carbon production, you’ll still average less than 20% of the CO2 you’d generate on a cruise at the same time.
Stopping Unlawful or Excessive Pollution From Cruise Ships: No Simple Task
The picture for cruise ship emissions grows grimmer when you consider that those statistics are based on data collected on the lawful emissions of cruise ships. There are definite ways in which governments can have a significant impact on limiting how much cruise ships pollute, as can be seen with the example of the California Air Resources Board.16
One of the unfortunate realities of capitalism is that large companies have a substantial motive to break the rules in order to save money and that the governmental apparatus for regulating emissions and punishing rules violators is often unable to keep up.
In 2019, Carnival Corporation was fined 20 million dollars for six violations of federal laws regarding the dumping of wastewater, plastics, and other wastes. The same year, they reported a total annual profit of 3 billion dollars,8 so it seems clear that the fines in place aren’t sufficient to actually discourage these companies from continuing these negative behaviors.
This study from the University of Michigan goes further into detail about the unique situation cruise lines face.17 Cruise ships have a massive environmental impact, only becoming more pronounced as more and larger ships are built, and yet regulating them has proven to be a difficult prospect because they move between so many different jurisdictions.
How Much Is a Cruise?
If you’ve never been on a cruise, the idea of the imposing price tag may be one of your reasons why. The initial price tag for a whole cruise can be daunting, and the idea of taxes, fees, port expenses, tips, and other “hidden” expenses certainly doesn’t make a cruise seem more affordable.
While some luxury lines may offer all-inclusive cruises where you pay one fee upfront and then don’t have to worry afterward, calculating the overall cost of most cruises may overwhelm you because of the number of variables to consider.
If you are going on a cruise with one of the larger cruise companies (Carnival, Royal Caribbean, and Norwegian Cruise Lines which make up around 72% of all cruise revenues annually), the price will vary depending on how many stops the cruise will make, how many nights you’ll be aboard, what type of room you’re going to get, and the level of luxury to be expected as a part of the specific cruise line you’re patronizing.
If you’ve seen advertisements for cruise ships, you’ve probably seen that they list prices for voyages “starting from” a specific price. On the larger cruise lines, these prices will get you a cabin on the interior of the ship with no exterior views, and typically will also include baseline dining, entertainment, and amenities onboard.
If you want a view, a balcony, expanded amenities, or other additions, those will increase the price. Taxes, port expenses, and other fees will add to this as well, as will gratuities for crew members and staff.
If you want to save as much money as possible on a cruise, first see what deals or packages are available, as you may be able to bundle certain perks together for a lower price. Shorter voyages are naturally going to be less expensive, and traveling on older ships with fewer advanced features can also lower the price.
You also can save money by planning a cruise during a region’s off-season, which varies depending upon the part of the world you’re considering.
How Do Cruise Ships Float?
Looking at modern cruise ships, with their towering hulls reaching ever greater heights above the water’s surface, you could very reasonably be confused as to how they are able to stay afloat.
As you may know, the principle of buoyancy dictates that in order for an object to float, it must weigh less than the water it displaces.
While it may seem impossible, there are a number of design elements used to ensure that cruise ships are able to stay above water in most circumstances.
First, the shape and construction of the hull help keep cruise ships afloat. Most big cruise ships will have hulls with a wide, deep, rounded hull, which helps to evenly distribute the weight of the ship.
This hull shape also helps to keep the ship’s center of gravity low, making the ship more stable.
Also helping to keep your cruise ship upright is the fact that the heaviest pieces of machinery, the engines, fuel, and generators, are all kept low in the hull, bringing the center of gravity lower. Furthermore, the ways in which these ships are used can limit this risk as well; many of the largest cruise ships avoid going out on the open ocean, sticking to areas where sea conditions are milder in order to avoid any big disruptions.
Why Cruises Are Bad: What’s the Truth?
While they are a very popular industry, with billions in revenue generated every year, cruises definitely have their downsides.
In a world still recovering from the pandemic, you may remember stories like this one recorded by Boston University,9 when during the early stages of the pandemic hundreds of people were forced to stay quarantined onboard cruise ships as disease ran rampant.
While Covid may be the most famous disease to impact cruise ships, it is far from the only one you need to worry about if you go on a cruise.
Putting thousands of people together in close quarters for days at a time where food is famously served buffet style is a great recipe for diseases like influenza, chicken pox, measles, and (frequently) norovirus to spread like wildfire among the passengers aboard a cruise ship.
Parasites like bedbugs can also spread rapidly aboard a cruise ship and are notoriously difficult to eradicate.
Even if you manage to avoid an epidemic, your other medical needs may not be met adequately by the shipboard medical facilities.
Cruise ship doctors, beyond not having full access to the resources of a hospital at their disposal, are often not able to practice medicine in the US, instead they are only qualified to practice in whatever country the ship is registered in.
(Image: MustangJoe21)
This means that, if you develop a serious medical condition on a cruise, the only people available to treat you may not be the best-qualified professionals.
Avoiding a severe medical issue still might not leave you clear to enjoy your cruise. The rocking motion of a ship at sea can combine with rich buffet meals and abundant alcohol can be a recipe for severe seasickness, which would really put a damper on your vacation.
Suppose you’re willing to risk health hazards in order to explore exotic locales, be prepared for disappointment. The emphasis with most cruise lines is on time spent aboard, not excursions to shore, so you may find yourself with scant time to explore much on land while you travel.
Carbon Footprint of Cruise Ships: What Does the Future of Cruise Ships Look Like?
As the global climate crisis worsens, leisure activities with massive carbon footprints like cruises are going to be among the first industries you’ll see needing to alter their behavior in order to lessen their impact.
Given the disproportionately high carbon footprint of cruise ships, the industry is under significant external pressure to change and has begun to improve.
(Image: Filip Filipović20)
You can already see, as mentioned above, a gradual shift toward less-polluting forms of fuel like biofuel and liquified natural gas. These shifts are being made in the here and now, albeit gradually.
But when you look to the future, you may see even more dramatic changes in the cruise industry.
Electric Cruise Ships
When you think of more efficient, environmentally-conscious sources of power, naturally shifting away from combustion power entirely to an electric system is one of the first ideas that come to mind. This idea has begun to be implemented, on a somewhat smaller scale; Yichang, China is home to the Yangtze River Three Gorges 1, which lays claim to the title of “the world’s largest electric cruise ship”.
This vessel, which has been in operation since 2022, can carry up to 1300 passengers at a time.
You still have a while to wait, however, before you can expect to see Carnival or Royal Caribbean launching electric ships because the technology is still developing; Yangtze River Three Gorges 1 has a range of about 60 miles on a full charge, a far cry from the hundreds or thousands of miles oceanic cruises cover between ports.
Further, the largest cruise ships have maximum capacities of more than 5 times what’s been seen to be possible with electric ships at present, so both the distance and scale of electric cruise ships still need to be improved significantly before you can expect to book an oceanic cruise on an all-electric ship.
Eco-Friendly Cruise Ships: Reducing Cruise Ship Emissions
More than ever, tourists are beginning to express significant concern about how their vacation choices impact the environment. According to Yale University,18 this has played a significant role in pushing cruise ship companies to improve their environmental impact and find new technologies to make cruise ship travel more friendly to nature.
Outside of going fully electric, there are a variety of ways cruise ships are becoming more environmentally friendly, but they’re still far more polluting than most other forms of travel. While some cruise lines have launched ships fueled by liquid natural gas, some are advancing still further by installing hybrid systems.
These systems allow the ships to run on battery power for a certain window of time, allowing them to go in and out of port or to navigate popular regions close to short like the fjords of Norway with minimal air pollution. While they still rely on LNG or fuel oil systems once that charge runs out this is still a step in the right direction; hopefully, the first of many.
Another technology making cruise ships more eco-friendly is Selective Catalytic Reduction, a system that when installed on a cruise ship can reduce the ship’s nitrogen oxide emissions by up to 80%.
One big advantage of these systems is that they can be retrofitted onto older existing ships, making them a more immediately actionable step cruise companies can take than building entirely new ships.
(Image: Sabrap5919)
There are other systems being developed to reduce the damage cruise ships do to the environment as well. Some ships are being built to use the heat generated by engines, laundry, and other machinery to heat swimming pools, produce steam, or otherwise aid in the ship’s functions.
Others are being built to produce less noise pollution to be less harmful to marine wildlife.
Another area of focus for cruise companies in becoming more eco-friendly is in minimizing the resource consumption or damage done by their passengers. Some cruise lines have begun relying on QR codes and apps to minimize paper consumption, while others have begun making sure that their passengers have access to coral-safe sunscreen and other products designed not to disrupt the ecosystems their passengers are about to visit.
How To Erase the Carbon Footprint of Cruise Ships
While cruise ship companies have made notable progress in reducing their negative impact on the environment, the truly staggering scale of their threat to the ecosystem means that they still have a long way to go before they are anywhere near other options for your next vacation in terms of environmental harm.
Fortunately, there are things that you can do right now to erase the carbon footprint of cruise ships, so that you can have a zero-emissions vacation and see the beautiful sea sights without guilt.
Tree planting carbon offsets can plant trees to sequester the carbon emissions from your trip. A weekend escape offset can cover it, or you can calculate the full emissions of the trip using a travel emissions calculator or a combination.
When planning your next vacation, keep the carbon footprint of cruise ships in mind, and if you end up deciding to take a cruise, think about steps you can take to try to compensate for that harm to the environment.
Read More About Carbon Footprint of Cruise Ships
11 Direct Air Capture Stocks to Watch in 2023 (Ranked by Carbon Offset Expert)
18 Meat Carbon Footprint Facts: The Emissions of Every Meat Type
2023 Plastic Carbon Footprint: Official Emissions Numbers + Calculator
2023 Prius Carbon Footprint: Shocking Fact About Toyota Emissions
25 Disadvantages of Renewable Energy (Pros and Cons Renewable Resources)
3 Research Groups Working on Reducing and Converting CO2 into Renewable Energy (REC)
3 Steps to Sell Carbon Credits: Make Money Saving the Planet!
3 Things Missing in EPA’s Carbon Footprint Calculator
37 Climate Change Volunteering Choices To Pick From
5 Organizations that Plant Trees: How to Choose in 5 Steps
6 Carbon Credit Exchanges (and Why Number 4 is the Best)
70 Environmental Facts in 2023 (Vegan, Science, Scary Facts, Positive Facts)
734 Trees: How Many You’d Have to Plant to Offset Your Carbon Footprint
8 Best GHG Registries Approved For Offsetting Carbon Emissions
Agricultural Carbon Offsets: Farmers Joining the Voluntary Carbon Marketplace in 2023
Agroforestry Facts Quiz: How Much Do You Know About These Systems?
Air Freight vs Sea Freight Carbon Footprint (The Real Numbers in 2023)
American Airlines Carbon Offsets but Delays Commitment to Carbon Neutrality
Are McDonald’s Fries Vegan? It Depends (Simple Trick to Know for Sure)
Audi CO2 Emissions Calculator: Carbon Footprint of All Models
References
1McKee, R., Reitman, F., Schreiner, C., White, R., Charlap, J., O’Neill, T., & Olavsky Goyak, K. (2013). The toxicological effects of heavy fuel oil category substances. [Print]. International Journal of Toxicology.
2Carnival Corporation. (2023). Alternative Fuels. Carnival Sustainability. Retrieved July 16, 2023, from <https://carnivalsustainability.com/alternative-fuels>
3Dijkstra, C., & Simon, V. (2023, June 6). The Return of the Cruise: How Luxury Cruises Are Polluting Europe’s Cities. Transport & Environment. Retrieved July 19, 2023, from <https://www.transportenvironment.org/wp-content/uploads/2023/06/The-return-of-the-cruise-June-2023.pdf>
4Carnival Corporation. (2023). Our Brands. Carnival Corporation. Retrieved July 18, 2023, from <https://www.carnivalcorp.com/corporate-information/our-brands>
5Royal Caribbean Group. (2023, June 30). About Royal Caribbean Group. Royal Caribbean Cruises Ltd. Retrieved July 18, 2023, from <https://www.rclinvestor.com/about-us/>
6Griffith Institute for Tourism. (2023). Cruise ship Emissions – Global Sustainable Tourism Dashboard. Global Sustainable Tourism Dashboard. Retrieved July 15, 2023, from <https://www.tourismdashboard.org/explore-the-data/cruise-ship/>
7Morgan, S. (2017, July 10). Daily emissions of cruise ships same as one million cars. EURACTIV.com. Retrieved July 19, 2023, from <https://www.euractiv.com/section/air-pollution/news/daily-emissions-of-cruise-ships-same-as-one-million-cars/>
8Cruise Industry News. (2019, December 20). Carnival Corp. Reports Q4 and Full Year 2019 Earnings. Cruise Industry News. Retrieved July 18, 2023, from <https://cruiseindustrynews.com/cruise-news/2019/12/carnival-corp-reports-q4-and-full-year-2019-earnings/>
9Lanz, L., Feltault, M., & Fauci, A. (2020, July 8). The Case of the Diamond Princess: Stranded at Sea in a Pandemic (Part 1) | Boston Hospitality Review. Boston University. Retrieved July 27, 2023, from <https://www.bu.edu/bhr/2020/07/08/the-case-of-the-diamond-princess-stranded-at-sea-in-a-pandemic/>
10Wikipedia. (2023, July). Cruise ship. Wikipedia. Retrieved July 27, 2023, from <https://en.wikipedia.org/wiki/Cruise_ship#Environmental_impact>
11Regents of the University of Michigan. (2023). Carbon Footprint Factsheet | Center for Sustainable Systems. Center for Sustainable Systems. Retrieved July 27, 2023, from <https://css.umich.edu/publications/factsheets/sustainability-indicators/carbon-footprint-factsheet>
12Georgetown University. (2023). Simple Tips to Reduce Your Carbon Footprint. Sustainability at Georgetown University. Retrieved July 27, 2023, from <https://sustainability.georgetown.edu/community-engagement/things-you-can-do/>
13National Park Service. (2020, December 4). Cruise Ship Standards of Care (U.S. National Park Service. Retrieved July 27, 2023, from <https://www.nps.gov/articles/000/cruise-ship-standards-of-care.htm>
14U.S. Energy Information Administration. (2022, April 13). Biofuels and the environment – U.S. Energy Information Administration. EIA. Retrieved July 27, 2023, from <https://www.eia.gov/energyexplained/biofuels/biofuels-and-the-environment.php>
15Bureau of Transportation Statistics. (2017, May 20). Table 1 Summary of Cruise Ship Waste Streams. Bureau of Transportation Statistics. Retrieved July 27, 2023, from <https://www.bts.dot.gov/bts/bts/archive/publications/maritime_trade_and_transportation/2002/environmental_issues_table_01>
16California Air Resources Board. (2020, August 27). California approves updated “At-Berth” regulation, expanding efforts to cut pollution from ships in California ports. California Air Resources Board. Retrieved July 27, 2023, from <https://ww2.arb.ca.gov/news/california-approves-updated-berth-regulation-expanding-efforts-cut-pollution-ships-california>
17Bulkley, J. W., Nadel, R., Commoy, J., & Polityka, C. A. (2005, May 15). The Environmental Impact of Cruise Ships. Center for Sustainable Systems. Retrieved July 27, 2023, from <https://css.umich.edu/publications/research-publications/environmental-impact-cruise-ships>
18Meek, K. (2018, November 27). Loyalty to “green” brands pushes the cruise industry towards better seas. Yale Environment Review. Retrieved July 27, 2023, from <https://environment-review.yale.edu/loyalty-green-brands-pushes-cruise-industry-towards-better-seas>
19Photo by Sabrap59. Pixabay. Retrieved from <https://pixabay.com/photos/cruise-ship-travel-vacation-827773/>
20Photo by Filip Filipović. Pixabay. Retrieved from <https://pixabay.com/photos/msc-cruises-venezia-port-boat-2940643/>
21Photo by MustangJoe. Pixabay. Retrieved from <https://pixabay.com/photos/cruise-ship-ocean-sea-travel-1236642/>
22Photo by Jürgen Sieber. Pixabay. Retrieved from <https://pixabay.com/photos/fine-dust-cruise-ship-3672343/>