Blog: Sailing Toward Sustainable Cruising

Blog: Sailing Toward Sustainable Cruising

As the popularity of cruising as a way to travel the world grows, so do the sizes of the passenger ships and the commitment by the industry to be stewards of the seas and oceans.
Seeing the world as a passenger aboard a cruise ship currently represents only 2 percent of the global tourism industry. But cruising is growing in popularity, and to meet demand and compete for patrons, cruise ship lines are building larger, more luxurious ships that offer endless prepared food, air-conditioned cabins; huge swimming pools, and other amenities that require a lot of energy to produce. 

Today, more than 300 ships transverse the globe every day, and the number of passengers is forecast to reach almost 40 million by 2027. With so many people traveling through the oceans and seas, disembarking to crowded shorelines, and tripling their personal carbon footprint while on the trip, it’s no wonder that environmentalists are worried.

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According to Popular Science, each floating hotel can burn up to 250 tons of fuel a day. Because of the nature of the ship—providing fuel-intense passenger “comforts”—they are the worst in an industry that already accounts for 2.9 percent of global carbon dioxide emissions. The largest cruise ship to date personifies the situation. The Royal Caribbean’s Icon of the Seas, launched in January, features 20 decks, six water slides, and the largest swimming pool at sea. With a length of nearly 2,000 feet, it weighs 250,800 GTs and can accommodate up to 7,600 passengers. 

But while the mainstream may be moving to bigger as better, some investors are looking to bring a totally green perspective to cruising. The Hurtigruten Group, for example, is working with its partners on a net-zero ship called SeaZero. This 443-foot-long ship for 600 guests and crew uses solar, AI, and 60 MWh batteries that display their charge levels on the external sides of the ship.

Still, many within the cruising industry are responding to increased criticism and are embracing sustainability tactics. Almost every cruise line is investing in some green initiatives, Colleen McDaniel, editor-in-chief of Cruise Critic, told CNN. And the industry’s trade group, Cruise Lines International Association (CLIA), has members committed to netzero carbon emissions by 2050. 

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More cruise lines are expanding their energy strategy and are incorporating multi-fuel engines, testing new fuel cell technology, adding wind (including solid sail) and photovoltaic solutions, and including power-shaving battery storage, CLIA reported in a press release. Moreover, 171 CLIA member ships are tracking and measuring energy efficiency. Fuel flexibility is part of the mix. Lines are testing new propulsion technologies via 32 pilot projects and collaborative initiatives underway with fuel and engine companies.

In its latest report, “Environmental Technologies and Practice, CLIA Global Oceangoing Cruise Lines,” CLIA reported that of the 44 new ships that members have been investing in since 2019, 25 will be liquified natural gas (LNG)-powered and seven will be either methanol-ready on delivery or methanol capable. “LNG has virtually zero sulfur emissions and particulate emissions, reduces NOx emissions by approximately 85 percent, and achieves up to a 20 percent reduction in greenhouse gas emissions,” CLIA reported.

Cruise lines are also studying alternative fuel sources looking to run on renewable fuels, including biofuels and synthetic carbon fuels. Currently, four ships use renewable biofuel as an energy source. And an additional four new builds are expected to be configured for renewable biofuels, CLIA reported. Finally, 24 ships are trialing biofuel and two looking at synthetic carbon fuel. 

Seven new-build ships are anticipated to run on zero carbon fuels, including five set to use green methanol and two to use green hydrogen, CLIA reported. “15 percent of new-build cruise ships entering service in the next five years are anticipated to be equipped with battery storage and/or fuel cells to allow for hybrid power generation,” it reported. CLIA highlights of progress include plugging into shoreside electricity, which allows cruise ships to plug into cleaner, landside electrical power and turn off diesel engines while at berth. “As a result, each cruise ship that plugs in can reduce diesel emissions by 80 percent and CO2 emissions by 66 percent on average,” reported the Port of Seattle. Currently, 120 ships have the ability to connect to shoreside electricity. By 2028, more than 210 ships will have shoreside power capabilities.

CLIA cruise lines has published its commitment to not discharge untreated sewage anywhere in the world during normal operations. Currently, 202 are equipped with advanced wastewater treatment systems. These systems, CLIA reported, operate to a higher standard than shoreside treatment plants in many coastal cities. Finally, more than 79 percent of cruise lines’ global capacity uses exhaust gas cleaning systems to meet or exceed air emissions requirements, Sea Cruise News reported.

Cathy Cecere is membership content program manager.

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