Climate Change

Icon of the Seas: Is the world’s largest cruise ship environment friendly?

It runs on LNG and can leak some of it directly into the atmosphere as methane, a greenhouse gas worse for the climate in the short term when compared to conventional fuels

By DTE Staff
Published: Friday 02 February 2024

On January 27, 2024, the world’s largest cruise ship named ‘Icon of the Seas’, set sail from Miami, Florida. Estimated to be five times larger than the Titanic, it is 365 metres long from bow to stern, has 20 decks and can house a maximum of 7,600 passengers.

Publicised as the “most sustainable ship to date”, the ship runs on dual-fuel engines to cut emissions and increase fuel efficiency by 24 per cent. But among such tall claims, there are growing concerns over the enormous methane emissions of the ship.

The launch of the ‘Icon of the Seas’ comes as many European countries crack down on cruise ships with new regulations aimed at targeting pollution in ports.

Traditional marine fuels have been a major cause of emissions in ships. Data shows that Europe’s 218 cruise ships emitted more sulphur oxides (SOX) than 1 billion cars in 2022. The most efficient cruise ships emit around 250g of carbon dioxide (CO2) per passenger kilometre which is 2.25 times the carbon intensity of a short-haul flight (111.1g).

The ‘Icon of the Seas’ is built to run on liquefied natural gas (LNG), which burns more cleanly than traditional marine fuel. Burning LNG releases less nitrous oxide, sulphur dioxide and particulate pollution than traditional fuels. LNG ships also cut CO2 emissions by 25 per cent in port.

Even though the idea of LNG ships looks good on paper, several experts have pointed out the flaws in this system. A 2023 investigation by environmental activists found that cruise ships running on LNG often leak some of it directly into the atmosphere as methane, a greenhouse gas that is 80 times more potent than carbon dioxide and is worse for the climate in the short term when compared to conventional fuels.

“It’s a step in the wrong direction. We would estimate that using LNG as a marine fuel emits over 120 per cent more life-cycle greenhouse gas emissions than marine gas oil,” Bryan Comer, director, Marine Programme, International Council on Clean Transportation, told news agency Reuters.

According to a 2020 greenhouse gas study by the International Maritime Organization (IMO is the United Nations body that regulates global shipping), the use of LNG as a marine fuel grew 30 per cent between 2012 and 2018, resulting in a 150 per cent increase in methane emissions from ships.

Though newer ships with more sustainable engines and forward-thinking solutions are on the way, environmental groups argue that many that are being built today will likely still be in service by 2050 when the IMO aims to reach its net-zero target.

But the question remains: Are we taking enough measures to attain this goal in the given period of time?

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