Miami - The world's largest cruise ship embarked on its inaugural journey from Miami, Florida, raising concerns about its methane emissions. The Icon of the Seas, stretching 365 meters (1,197 feet) with 20 decks accommodating up to 7,600 passengers, is owned by the Royal Caribbean Group. This massive vessel is set for a seven-day tropical island-hopping voyage.

Despite being powered by liquefied natural gas (LNG), known for cleaner combustion than conventional marine fuels, environmentalists worry about potential methane leakage. Methane, a highly potent greenhouse gas, poses a greater threat to the atmosphere than carbon dioxide.

Bryan Comer, director of the Marine Programme at the International Council on Clean Transportation (ICCT), expressed concern, stating that using LNG as a marine fuel could emit over 120% more life-cycle greenhouse gas emissions than marine gas oil.

A recent ICCT report argues that methane emissions from LNG-fueled ships exceed current regulatory assumptions. The ship features seven swimming pools, numerous bars, restaurants, and even a funfair on its top deck.

Royal Caribbean claims that the Icon of the Seas is 24% more energy-efficient than the International Maritime Organization's requirements for modern ships. Despite environmental concerns, the company aims to introduce a net-zero emissions ship by 2035.

The $2 billion (£1.6 billion) Icon of the Seas boasts an array of amenities, including seven swimming pools, six waterslides, and over 40 restaurants, bars, and lounges. During the ship's naming ceremony, Argentine football legend Lionel Messi, currently playing for Inter Miami, participated in the traditional "good luck" breaking of a champagne bottle against the vessel's bow.