• Wastewater Treatment Standards: Royal Caribbean utilizes Advanced Wastewater Purification (AWP) systems that clean sewage to levels cleaner than many land-based municipal treatment facilities
• LNG Propulsion Strategy: The Icon of the Seas runs on Liquefied Natural Gas to reduce carbon emissions, though this choice remains controversial due to concerns over methane leakage
• Shore Power Connectivity: To reduce port pollution, newer ships are designed to plug into local electrical grids while docked, eliminating the need to run engines in port
• Long-Term Climate Goals: The company has reaffirmed its “Destination Net Zero” target, aiming to introduce a net-zero emissions vessel by 2035 and achieve total carbon neutrality by 2050

In response to growing environmental scrutiny regarding mega-ships like the Icon of the Seas, Royal Caribbean Group has highlighted the data within their “Destination Net Zero” sustainability strategy. Addressing the specific criticisms regarding sewage and emissions, the company points to their Advanced Wastewater Purification (AWP) systems.

According to their reports, these systems treat wastewater to standards twice as stringent as US federal regulations for land-based municipal water treatment, using bioreactors and UV disinfection to clean water before discharge. They also emphasize that 90% of all freshwater used on board is produced directly from seawater via reverse osmosis and steam evaporation, reducing the strain on local port supplies.

Regarding the “emissions” complaints, Royal Caribbean acknowledges the challenge but defends the Icon of the Seas as their most energy-efficient vessel to date. The ship is powered by Liquefied Natural Gas (LNG), which the company states reduces overall carbon dioxide emissions by approximately 30% compared to traditional marine fuel oils. However, they also face continued criticism regarding “methane slip”—the potential for unburned methane to escape from LNG engines—which some environmental groups argue could offset carbon savings. To mitigate fuel use, the ship utilizes air lubrication technology to reduce hull friction and is fully equipped for shore power. This allows the vessel to turn off its engines and plug into the local electric grid while docked, a capability that was successfully launched at PortMiami in 2024. The company maintains its commitment to achieving a net-zero cruise ship by 2035 and net-zero emissions for the entire fleet by 2050.