Cruise ships are generally worse for the environment than planes, emitting significantly more CO2 per passenger-kilometer, plus vast amounts of sewage, hazardous waste, and air pollutants, causing more damage to marine ecosystems and human health, although flying also has a high impact, especially from high-altitude non-CO2 effects.
In fact, taking a cruise is worse than flying – with the average cruise ship trip resulting in anywhere from 700 to 1,000 pounds of carbon dioxide emissions per day.
Water Pollution
The US Environmental Protection Agency estimates that a 3,000-person cruise ship generates 176,400 gallons of sewage per week. This adds up to over one billion gallons of sewage a year for the industry – the equivalent of 1,515 Olympic-sized swimming pools.
Fossil fuels – coal, oil and gas – are by far the largest contributor to global climate change, accounting for around 68 per cent of global greenhouse gas emissions and nearly 90 per cent of all carbon dioxide emissions. As greenhouse gas emissions blanket the Earth, they trap the sun's heat.
Admittedly, air transport is extremely polluting – but so are cars. Air traffic represents less than 2-3% of the global CO2 emissions whereas road traffic accounts for around 10% of these direct emissions. Still, planes remain among the most polluting means of transport, together with cars.
Fuel & Energy is the top polluter, contributing to around 75% of global greenhouse gas emissions, mainly through fossil fuels like coal, gas, and oil.
However, all of our jet-setting and road-tripping comes with a hefty carbon footprint. Today, transportation is tourism's main source of greenhouse gas emissions. On average, planes and cars generate the most CO2 per passenger mile, with tour buses, ferries, and trains coming well behind.
More than 90 percent of the warming that has happened on Earth over the past 50 years has occurred in the ocean.
Fossil fuels—including coal, oil, and natural gas—have been powering economies for over 150 years, and currently supply about 80 percent of the world's energy.
Poop on a cruise ship goes into an onboard sewage treatment system (black water), not directly into the ocean; it's treated using bacteria and filtration to break down solids, then sterilized (often with UV light), and the resulting clean water is either discharged far from shore (following strict international rules) or stored until the ship reaches port for disposal on land, while solids are often incinerated or landfilled.
Greener energy
Historically, cruise ships have been powered by high-polluting heavy fuel oil. In recent years, biofuels have been tested by cruise lines to serve as viable alternatives. When a ship is docked, power cables connect to greener energy sources instead of using fuel-guzzling engines.
This waste not only carries bacteria and viruses that are harmful to human health, but can also sicken and kill marine life, including corals. U.S. law allows cruise ships to dump raw sewage in the ocean once a ship is more than three miles off U.S. shores.
Depending on the statistics you cite, long-haul air freight can generate 47 times as much greenhouse gas emissions as ocean freight, per ton-mile.
Hurtigruten is also a pioneer in waste reduction. The company does not use any single-use plastic at all, and suppliers are also selected on the basis of sustainability. Some of the crew's uniforms are made from recycled fishing nets, and the food served on board is sustainably and locally sourced.
Cruise ships are known to be heavy carbon emitters. A medium-sized cruise ship emits greenhouse gases equivalent to those of 12,000 cars, and it could dump over 1 billion gallons of untreated sewage into the ocean.
Is Taylor Swift's carbon footprint really that high? Yes, with her 2022 flight emissions totaling in at a whopping 8,293 tonnes – Taylor Swift is known to have one of the highest celebrity carbon footprints of all time.
Bangladesh is frequently cited as the world's most polluted country based on average annual PM2.5 (fine particulate matter) levels, followed closely by Pakistan and India, with high concentrations driven by vehicle emissions, industrial output, and construction, though Chad sometimes tops the list in specific reports, highlighting ongoing severe air quality challenges in South Asia and parts of Africa.
Carbon footprints of superyachts owned by five of the wealthiest exceed those of the private jets owned by 10 of the 12 billionaires. Mexican businessman Carlos Slim, the 12th richest man in the world and former part owner of the New York Times, emits 7 million tonnes of CO2, more than any other billionaire.
The Northeast offers better prospects, particularly Vermont and New Hampshire, which rank as the two safest states from climate change. Vermont stands out as a haven – free from wildfires, extreme heat, and hurricanes.
Tuvalu is widely considered one of the first countries likely to be significantly impacted by rising sea levels due to global climate change. According to some estimates, the highest tides could regularly flood 50% of the land area of national capital Funafuti by the mid-21st century, and 95% by 2100.
Earth's global temperature in 2024 was 2.3 degrees Fahrenheit (or about 1.28 degrees Celsius) warmer than the 20th century baseline 1951 - 1980. NASA records show global temperature was 2.65 degrees Fahrenheit (1.47 degrees Celsius) warmer than the late-19th century (1850 - 1900) preindustrial average.
In fact, unless you're looking to venture from Los Altos to LA off-road through state parks the whole way—in a Hummer with Tonka-truck mud tires—driving is generally greener than flying.
Antarctic Cruise (14 days) - 8.4 tonnes of CO2e per person. This trip tops the list of the highest emitting holidays. Included in our assumptions are flights to Ushaia on the southern tip of Argentina via Buenos Aires, a short taxi transfer and accommodation on the ship.
Bhutan is the world's first carbon-negative country; its vast forests absorb more carbon dioxide (CO2) than the country emits from all activities.