Can you have a clean cruise vacation and which ships are the biggest emitters? | Cruises

How environmentally friendly is my cruise vacation?

While the cruise sector represents only a tiny portion – just 2% – of the shipping industry, ships are increasing in size and number. Therefore, they need to do more than before towards sustainability, says Inesa Ulichina, sustainable shipping officer at campaign group Transport & Environment (T&E).

“One of the reasons we focus on cruise ships is because they are close to people,” she says. “Cruise ships spend proportionately more time in port than other ships, particularly in pristine and natural places where the impact of pollution is greater.”

Critics say the cruise boom — the number of ships has risen from 21 in the 1970s to 515 today and the world’s largest have doubled since 2000 — is dwarfing the decarbonization efforts of individual shipping companies and ships. A study commissioned by the High-Level Panel on a Sustainable Ocean Economy concluded that the 2% annual improvements in carbon intensity reported by two leading cruise lines in recent years were “many times wiped out” by an expected increase of 6 to 7% “will be passenger traffic.

“If we look at Europe, the most emitting ships are cruise ships or large ferries,” says Ulichina.

A list of Europe’s 20 biggest carbon emitters, compiled by T&E using data required by EU laws for ships to report carbon dioxide emissions, includes nine of the largest cruise ships, 10 ferries and just one cargo ship.

According to Sintef, a European research organization, up to 40% of a cruise ship’s total energy consumption comes from onboard “hotel operations” – swimming pools, spas, lounges and restaurants.

Not surprisingly, according to a T&E study, cruise ships emitted 17% more carbon dioxide in 2022 than in 2019, while methane emissions rose 500% over the same period.

So should I choose a ship that runs on a different fuel?

Earlier this year, the Icon of the Seas, a 20-deck, 7,600-passenger party ship rich in theme parks and longer than the Eiffel Tower, drew crowds when it was launched in Miami. It runs on liquefied natural gas (LNG), which its owner, Royal Caribbean, calls the “cleanest-burning marine fuel on the market.” Another similarly sized ship, Star of the Seas, will follow in 2025 and a third in 2027 – all powered by LNG.

According to the Cruise Lines International Association (Clia), which represents 90% of operators in the sector, only 19 ships or 6.7% of the fleet are powered by LNG. By 2028 it will rise to 10%. More than 15% will be equipped with battery storage in the next five years and 15% can run on methanol, the first in 2025.

But environmentalists warn that while LNG, a fossil fuel, burns cleaner than marine oil, ships running on LNG risk releasing methane, a powerful greenhouse gas, into the air. Bryan Comer, director of the International Council on Clean Transportation, a U.S. think tank, estimates that using LNG as a marine fuel emits 120% more greenhouse gases than marine oil throughout its life cycle.

Marcie Keever of Friends of the Earth US says the industry has a history of adopting the “wrong” technology. When many cruise lines were asked to reduce airborne sulfur emissions in 2020, they introduced “scrubbers” instead. These are exhaust gas purification systems built into ships – instead, they discharge the chemicals removed from the exhaust gases directly into the sea.

“They (cruise companies) talk about switching to other types of fuel, but if they decide to use LNG, they are relying on climate-damaging technologies,” Keever says. “Our opinion is just a pause at the moment. Don’t adopt the next failing climate technology.”

Which cruise companies do best when it comes to sustainability?

While the larger ships (more than 10,000 gross tons) are the largest contributors, accounting for 90% of the sector’s total greenhouse gas emissions, companies with smaller ships tend to be leaders in decarbonization.

Hurtigruten, a Norway-based company that operates three small ships using hybrid technology, plans to launch SeaZero, the first zero-carbon electric cruise ship, in 2030.

“For expedition cruise ships, some companies like Hurtigruten are investing in batteries and ships that could be sustainable,” says Ulichina.

Gerry Larsson-Fedde, the company’s chief operating officer, admits that Hurtigruten’s goal of being a carbon-neutral ship by 2030 has “many dependencies,” such as whether or not the technology will be sufficiently mature. “We chose batteries because technology is evolving rapidly, meaning you can store more and more energy in less space and with less weight.”

One of the biggest challenges is land-based infrastructure, he says. “In charging areas you need a lot of power and you have to charge quite quickly.”

Sönke DIESENER from the Germany-based NGO Nature And Biodiversity Conservation Union says battery capacity depends heavily on the places a ship visits. “When they (Hurtigruten) sail on the Norwegian coast, they have infrastructure to recharge batteries. But the batteries would be too heavy for ships going to the Galapagos Islands or the Arctic.”

This is one of the reasons why cruise companies are turning to alternative fuels for larger ships.

There are companies that want to go even further – but only for smaller, high-quality ships. French polar company Selar aims to power the futuristic Captain Arctic, a 36-passenger polar expedition ship that uses sun, water and wind, by 2026. The “almost emissions-free” ship design features 35-meter sails that retract like a Swiss Army knife when at rest.

How does the industry plan to mitigate its impact on the climate?

Clia says its member cruise lines are investing in new ships and engines that “enable fuel flexibility.” This means they have integrated renewable biodiesel, green methanol where available and LNG capacity. Data released by the International Maritime Organization shows that cruise ships have reduced their use of heavy fuel oil from 74% in 2019 to 57% today.

According to Clia, ships powered by LNG can switch to renewable “zero and near-zero fuels” such as bio or synthetic LNG once these are available on a large scale and require little or no engine modifications.

Half of all ships can be connected to shore power, an increase of 23% compared to 2023. This share will increase to 76.5% by 2028. However, only 35 of the world’s ports (3% of the total) have a cruise berth with shore power supply.

The EU will impose significant penalties for driving with dirty fuel from next year and has set targets to reduce greenhouse gas emissions. It is hoped that this type of legislation, coupled with pressure from environmentalists and the public, could bring about further positive changes for cruise travel in the future.