I've been there, sailing the ocean for days while enjoying an endless buffet and swimming pools at sea. It's tempting, but... is it worth it?

The numbers are stark. According to an analysis by the International Council on Clean Transportation, cruise ships emit approximately 250 g of CO₂ per passenger-kilometer.

A study cited by Friends of the Earth reveals that the average tourist increases their carbon footprint eightfold simply by embarking on a cruise, compared with a land-based vacation of equivalent duration.

It's not just about carbon. A single cruise ship generates approximately one ton of solid waste per day and emits greenhouse gases equivalent to those of 12,000 cars, according to figures published by Sphera.

The U.S. Environmental Protection Agency estimates that a ship with a capacity of 3,000 passengers produces more than 176,000 gallons of wastewater per week; wastewater that, even after partial treatment, contains heavy metals, nutrients, and chemicals that are not biodegradable and are released into marine ecosystems.

The cruise industry is also responsible for discharging approximately 1.5 gigatons (a quantity difficult to quantify) of toxic wastewater annually from scrubbers.

It's important to note that scrubbers are systems designed to reduce air pollution from ship exhaust, but they do so by removing pollutants from the air and releasing them into the ocean.

Net-zero emissions goals are not new, and the cruise industry is no exception.

The Cruise Lines International Association (CLIA) has committed to achieving net-zero emissions by 2050. To this end, it regularly publishes reports highlighting investments in transition fuels, advanced wastewater treatment systems, and shore power.

Some companies, such as Hurtigruten and Ponant, have genuinely invested in cleaner technologies: wind-assisted propulsion, hybrid engines, and certified sustainability frameworks.

Although these may seem like real efforts, independent assessments tell a more complex story.

Friends of the Earth’s 2024 Cruise Ship Assessment Report evaluated 21 major cruise lines, with a total of 243 ships, against four criteria:

The result: only eight lines achieved a rating higher than D+.

Five cruise lines owned by Carnival Corporation received failing grades, and Carnival has been among the industry’s biggest polluters for years.

One of the most heavily promoted "green" solutions in the industry—liquefied natural gas (LNG)—has faced serious criticism.

The Dutch Advertising Board ruled that MSC Cruises' claims about LNG as a sustainable fuel were false and misleading.

Meanwhile, Friends of the Earth describes LNG as a "greenwashing fuel source" that increases the industry's climate footprint rather than reducing it.

Thus, transparency remains a critical issue. Some cruise lines refused to disclose data on their environmental performance to Friends of the Earth, resulting in automatic failing grades in that category.

This is the result of a revealing decision by companies that promote themselves as responsible stewards of the marine environment.

Some do — in isolation. Shore power connections allow docked ships to shut off diesel engines and draw from local electricity grids, reducing port-side air pollution.

Advanced waste treatment systems can meaningfully reduce the toxicity of wastewater discharge.

A handful of smaller expedition lines have made genuine structural commitments: Ponant offsets 100% of its emissions and conducts environmental impact studies before designing any itinerary, while Star Clippers operates on wind power up to 80% of the time.

These examples matter.

But they represent a tiny fraction of global cruise capacity. The majority of the industry — hundreds of ships carrying tens of millions of passengers — continues to run primarily on heavy fuel oil and LNG, discharge pollutants into some of the world's most ecologically sensitive waters, and oppose the regulatory changes that would force real reform.

A study published in August 2025 in the Journal of Sustainable Tourism found that emissions from onboard hotel services in Antarctica were higher than anywhere else in the world, precisely in the region where the ecological stakes are highest. The ships are literally dirtiest where the environment is most fragile.

My most honest recommendation and the shortest answer is: yes.

For me, it's hard to ignore the bigger picture. For the vast majority of travelers who book conventional cruises, the environmental impact is not positive.

These aren't marginal concerns. They're systemic problems.

But to be fair, not all cruises are created equal. Small expedition lines with genuine sustainability certifications, sailing propulsion, and complete environmental transparency are in a different league than a 7,600-passenger floating resort burning fossil fuels in the Caribbean.

If you're set on taking a cruise, opt for smaller, certified operators. Steer clear of the major cruise lines.

Sustainable tourism invites us to consider not only our own experiences as travelers, but also the negative impacts on the places and people we visit.

In this sense, the cruise industry, as it currently operates on a large scale, falls far short of actions that benefit us all as humanity.

The decision to embark on a cruise or not is yours, but keep in mind that it should ALWAYS be an informed one.