Global cruise operators have made continued progress towards cutting carbon emissions and adopting key sustainability measures by investing in new ships and technologies.

These are some of the key findings claimed by Cruise Lines International Association (CLIA), a leading association of the global cruise industry, that has released its annual Global Cruise Industry Environmental Technologies and Practices Report. 

It says that its members have showed continued progress in advancing its environmental and sustainability agenda, including investments in ships and technologies for the uptake of transitional and alternative fuels.

Kelly Craighead

“Cruise lines are continuing to reduce their emissions at sea and at berth in pursuit of net zero emissions by 2050. This year’s environmental technologies report demonstrates their progress, with the industry investing in engine technologies with conversion capabilities that will allow ships to use more renewable energy sources as they become available and making important incremental steps to employ a range of other environmental technologies and practices to advance the industry’s wider sustainability initiatives,” says Kelly Craighead, President and CEO of Cruise Lines International Association.

The report says that the CLIA member ocean fleet includes 303 ships and a total capacity of 635,000 lower berths operated by 45 cruise line brands representing 90 pc of capacity, an increase of 3.6 pc and 3.34 pc respectively, compared to the prior year.

It says that analysis of the current CLIA member cruise line fleet indicates that the majority of ocean-going ships operated by CLIA member cruise lines are small to mid-size ships, as 35 pc of ships are small ships with fewer than 1,000 lower berths, about 38 pc of ships are mid-size ships with 1,000-2,999 lower berths and 26 pc of ships are large ships, with 3,000 and more lower berths.

CLIA says that its member cruise lines are investing in new ships and engines that allow for fuel flexibility. This includes capability to use renewable biodiesel, investments in the capability to use green methanol when available, and liquified natural gas (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.

It says that 19 ships, representing 7 pc of the fleet and 13 pc of the fleet’s global capacity, are using LNG for primary propulsion.

LNG has virtually zero sulfur emissions and particulate emissions, reduces NOx emissions by approximately 85 pc and achieves up to a 20 pc reduction in GHG emissions. 

Multiple reports confirm that methane slip, the amount of methane that is released in the atmosphere, an acknowledged issue with LNG engines, is on a path to be nearly eradicated, with some industry stakeholders claiming that slip values of less than 1 pc is achievable within the next few years.

CLIA adds that 71 ships, representing 25 pc of the fleet and more than 20 pc of global capacity, have Selective Catalytic Reduction technology (SCR) that reduces particulate matter and nitrogen oxide emissions, thus helping ships to meet International Maritime Organisation (IMO) Tier III classification standards for nitrogen oxide emissions. It says that the number of ships using SCR has risen by 34 pc from 2023.

CLIA also claims progress in Onshore Power Supply (OPS) or Shoreside Electricity (SSE) capability as plugging in to OPS when ships are in port allows ships’ engines to be switched off, achieving significant overall pollutant emissions reductions of up to 98 pc, depending on the mix of energy sources, according to studies conducted by a number of the world’s ports and the US Environmental Protection Agency.

Across the CLIA cruise line member fleet, 147 ships are able to connect to OPS, 52 pc of the total number of ships and 61 pc of capacity,  23 pc more than the prior year and 167 pc more since 2018.

By 2028, 239 ships that are able to connect to OPS are expected to be in service, based on the number of ships scheduled to be retrofitted and new ships on the order book specified for OPS connectivity. This includes 64 ships currently in service and each of the 28 CLIA member cruise ships on the 2024-2028 order book, all of which are specified for OPS connectivity.

CLIA says it champions the advancement of onshore power infrastructure as an important component in the industry’s work to reduce emissions and supports continued development of cost-effective infrastructure for clean shoreside electricity in cruise ports when the net impact delivers an overall emission reduction.

Currently only 3 pc or 35 of the ports worldwide where cruise ships call have a cruise berth with OPS, while 22 additional cruise ports are funded for OPS infrastructure and 16 cruise ports are planning to install OPS, making a total of 38 ports.

In 2022, CLIA announced that its ocean cruise line members made a commitment that all ships calling at ports capable of providing OPS 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.

CLIA says that as part of the ‘EU’s Fit for 55’ decarbonisation regulations, by 2030 major ports in Europe will be required to have shoreside power, which will further accelerate port infrastructure investment in that region.

Advanced Wastewater Treatment Systems (AWTS)

CLIA says that a majority of CLIA member cruise ships sailing today utilise advanced wastewater treatment systems (AWTS), which are capable of exceeding MARPOL Annex IV requirements and perform better than shoreside treatment plants in some coastal cities. In addition, as part of their overarching sustainability focus, cruise lines have committed to not release untreated sewage anywhere in the world during normal operations.

Across the CLIA cruise line member fleet, 225 ships or 80 pc of the total, representing 84 pc of global passenger capacity, are equipped with AWTS, an increase of 11 pc from 2023 and a rise of 65 pc from 2018.

It adds that over one-third of the ships equipped with AWTS are capable of meeting the more stringent wastewater release standards of the Baltic Sea Special Area.

It says that a majority of CLIA members produce their own fresh water onboard their ships, with 267 ships, representing more than 94 pc of reporting ships and 96 pc of global capacity, able to do so, of which 172, nearly 60 pc of the fleet, are capable of producing enough water to match their total consumption.