CLIA Releases Annual Report on Environmental Technologies and Practices

International

Cruise industry shows measurable progress in energy efficiency, alternative fuels, and emissions reduction

Data from 2018–2024 highlights advances in fuel-flexible engines, onshore power supply, wastewater treatment, and waste management across the global cruise fleet.

The Cruise Lines International Association (CLIA) has published its annual Environmental Technologies and Practices Report, profiling more than 90% of the world’s oceangoing cruise capacity. The report details measurable progress in environmental innovation — from piloting biofuels and deploying dual-fuel engines to expanding onshore power connectivity and advanced wastewater treatment.

“Cruise lines are early adopters of maritime technology, from advanced wastewater systems to dual-fuel engines. These innovations not only reduce emissions but also benefit the wider shipping sector,” said Bud Darr, CLIA president and CEO. “With more than 80 new ships on order worldwide, our members are investing tens of billions of dollars to build a more efficient, sustainable fleet.”

Key findings from the 2025 report

· Fleet profile: As of August 2025, CLIA’s 45 member cruise lines operate 310 ships with nearly 638,000 berths. Most ships (73%) are small to mid-size vessels with fewer than 3,000 berths.

· Fuel flexibility: Ships with multi-fuel engines have grown from one in 2018 to 19 today, all dual-fuel. By year-end 2025, 23 ships will be in service, including the first with tri-fuel capability. By 2036, 32 dual-fuel ships are expected, with seven able to use methanol and 25 LNG.

· Onshore power supply (OPS): 166 ships — 58% of the fleet — can now connect to shore power, up from 55 ships in 2018. By 2036, 273 ships are forecast to be OPS-capable. Currently, 41 ports worldwide provide at least one OPS berth, with Europe leading the expansion.

· Selective Catalytic Reduction (SCR): Ships with SCR technology have increased tenfold since 2018, from 7 to 81 vessels, cutting nitrogen oxide emissions to IMO Tier III standards.

· Freshwater production: 279 ships (over 98% of the fleet) can produce most of their own freshwater, reducing pressure on port resources.

· Wastewater treatment: 234 ships (82% of the fleet) now operate advanced wastewater treatment systems (AWTS), a 72% increase since 2018. More than a third already meet the stricter Baltic Sea Special Area standards.

· Waste management: Innovative onboard systems include waste-to-energy gasification (on 8 ships) and microbial food waste digesters (on 128 ships, 45% of the fleet), reducing landfill impact and energy demand.

Toward net-zero

The report emphasizes CLIA members’ pursuit of net-zero emissions through greater fuel flexibility, energy efficiency, and investment in new ship designs. Conversions and retrofits are expected to accelerate sustainability gains over the next decade, supported by stricter global and regional regulations.

For more information and to access the full report, visit cruising.org.