CLIA updates on cruising's environmental progress

This includes investments in ships and technologies for the uptake of transitional and alternative fuels.

'Cruise lines are continuing to reduce their emissions at sea and at berth in pursuit of net zero emissions by 2050,' CLIA President/CEO Kelly Craighead said. Investment in engine technologies with conversion capabilities will allow ships to use more renewable energy sources as they become available, and lines are making important incremental steps, she added, to employ a range of other environmental technologies and practices to advance the industry’s wider sustainability initiatives.

Fleet profile

The CLIA member ocean fleet includes 303 ships with a total of 635,000 lower berths operated by 45 cruise lines representing 90% of cruise industry capacity. Thirty-five percent of those ships are small (fewer than 1,000 lower berths), 38% mid-sized (1,000 to fewer than 3,000 lower berths) and 26% large (more than 3,000 lower berths).

Fuel flexibility

New ships and engines allow for fuel flexibility including the capability to use renewable biodiesel, the capability to use green methanol when available and LNG. Ships designed with engines and fuel supply systems able to operate on LNG will be able to switch to zero and near-zero fuels such as bio or synthetic LNG in the future, with no engine modifications.

19 LNG ships in service

Nineteen ships (representing 7% of the fleet and 13% of CLIA's global capacity) are using LNG for primary propulsion.

Reducing methane slip

LNG has virtually zero sulfur emissions and particulate emissions, reduces NOx emissions by approximately 85% and achieves up to a 20% reduction in greenhouse gas emissions. According to multiple reports, methane slip —an acknowledged issue with LNG engines — is on a path to be nearly eradicated, CLIA said, with some industry stakeholders claiming that slip values of less than 1% are achievable within the next few years.

Selective catalytic reduction technology

Some 71 ships (25% of the fleet and more than 20% of global capacity) have selective catalytic reduction (SCR) systems, an increase of 34% from 2023.

SCR reduces particulate matter and NOx emissions, thus helping ships to meet IMO Tier III classification standards NOx emissions.

Shore power-capable cruise ships

Plugging into shore power allows ships’ engines to be switched off, achieving significant overall pollutant emissions reductions of up to 98%, depending on the mix of energy sources, according to studies conducted by a number of ports and the US Environmental Protection Agency.

Across the CLIA member fleet, 147 ships are shore power-capable (52% of all the CLIA fleet and 61% of capacity). This is 23% more than the prior year and 167% more since 2018.

By 2028, 239 ships that are able to connect to shore power are expected to be in service, based on ships scheduled for refitting and newbuilds on order. This includes 64 ships currently in service and each of the 28 CLIA member cruise ships in the 2024- 2028 orderbook, all of which are specified for shore power connectivity.

CLIA considers shore power an important component in the drive to reduce emissions and supports continued development of cost-effective infrastructure for clean shoreside electricity at ports when the net impact delivers an overall emission reduction.

Ports offering shore power

Currently 35 of the worldwide ports visited by cruise ships (fewer than 3%) have a cruise berth with shore power.  

Some 22 additional cruise ports are funded for this infrastructure and 16 are planning to install it, so 38 more ports.

Commitment by 2035

In 2022, CLIA announced its ocean cruise line members committed that all ships calling at ports capable of providing shore power will be equipped to either use shore power by 2035 or be able to use alternative low-carbon technologies, as available, to reduce emissions in port.

As part of the EU’s Fit for 55 decarbonization regulations, by 2030 major ports in Europe will be required to offer shore power, which will further accelerate port infrastructure investment in that region.

Advanced wastewater treatment systems

CLIA said the majority of its member line ships use advanced wastewater treatment systems that are capable of exceeding MARPOL Annex IV requirements and perform better than shoreside treatment plants in some coastal cities. In addition, cruise lines have committed to not release untreated sewage anywhere in the world during normal operations.

Across the CLIA member line fleet, 225 ships (80%, representing 84% of global passenger capacity) are equipped with advanced wastewater treatment systems, an 11% increase from 2023 and a 65% increase from 2018.

More than one-third of the ships with this technology are capable of meeting the more stringent wastewater release standards of the Baltic Sea Special Area. 

Freshwater production

The majority of CLIA member ships produce their own fresh water, with 267 (more than 94% of reporting ships and 96% of global capacity) able to do so. Of those, 172 (nearly 60% of the fleet) are capable of producing enough water to meet their total consumption.

Data tables

Data tables for the CLIA report are available at cruising.org under Environmental Technologies and Practices CLIA Global Oceangoing Cruise Lines.