Seattle consistently ranks among the greenest cities in the nation. As early as 2009 the city mandated recycling. It has since embraced renewable energy production, banned environmentally harmful items like plastic straws and encouraged electric vehicles by increasing the number of public EV charging stations.

The city’s green initiatives extend to its port, including its two main cruise terminals, as well. In 2009 Seattle introduced shore power at Pier 91, allowing ships to turn off their diesel-powered engines while at their berth and plug into the city’s power grid instead. Construction challenges delayed adding shore power at Pier 66 until October 2024, but now all berths for cruise ships in Seattle can use the city’s energy.

Already, shore power use has had a significant impact. During the 2025 cruise season, the first season where shore power was an option at all berths, 68 percent of cruise ships plugged in, avoiding 6,444 tonnes of CO2e and 1.74 tonnes of diesel particulate matter, according to Stephanie Jones Stebbins, managing director for Maritime, Port of Seattle.

For perspective, cruise ships usually spend between eight and 10 hours at berth offloading guests, restocking provisions and welcoming new guests for the next departure. During that time ships have traditionally used their engines — which emit greenhouse gases, air pollutants and noise into the city — to power onboard essentials such as lights and elevators. Now they can rely on renewable energy available from the city’s grid.

Carnival Luminosa docked at Pier 91 © Iandewarphotography | Dreamstime.com

Last year Seattle passed legislation requiring all homeported cruise ships to plug into shore power while berthed at city piers beginning with the 2027 season. According to Seattle City Light, the city’s public electric utility, the mandate will result in an 80 percent reduction in diesel emissions and a 66 percent decrease in greenhouse gases.

The Port of Seattle’s green efforts don’t end there. Through a partnership with major cruise lines, home ports and ports of call, it’s currently studying ways to decarbonize cruising to Alaska. The goal is to have four sustainably powered cruise ships sailing in the corridor by 2032 and to eventually create the world’s first green corridor for cruising, The Pacific Northwest to Alaska Green Corridor. Ideally, the corridor will have zero emissions by 2050.

To that end, Stebbins said the Port of Seattle is exploring sustainable fuel options, including working with Carnival Corp. on a biofuel demonstration project. The port aims to identify the challenges — and possible opportunities — of using nonfossil fuels at the port on a large-scale basis, an essential step in its move toward zero emissions.

Like Carnival, most cruise lines operating in Seattle are working toward more sustainable cruising. Stebbins said operators have reduced emissions during their voyages by traveling more efficiently, and most ships now have advanced wastewater treatment systems that exceed international standards. This ensures cleaner discharges in ocean waters, which protects marine ecosystems.

Additionally, most cruise ships have nearly eliminated single-use plastics, and most prioritize responsible food sourcing by purchasing from suppliers that connect them to local growers and small businesses whenever possible. These efforts complement those of the Port of Seattle as it moves toward its goal of becoming the greenest port in North America, Stebbins said.

Sustainability in cruising should matter to passengers embarking and disembarking in Seattle, according to Stebbins, since almost all of them are traveling to one of the most beautiful natural environments on the planet, Alaska. Passengers should want to lessen their impact and preserve what they experience there for future generations.

“How we care for our environment within a cruise context matters,” she said.

“Norwegian Bliss” docked at Pier 66 © David Johnson | Dreamstime.com

Because many passengers spend time in Seattle before or after their cruise, even if only for a few hours, the city’s tourism industry also considers sustainability. One of the most recent examples is Waterfront Park, opened in September 2025. The 20-acre park features nearly 1,000 trees and treats 7.5 million gallons of stormwater — the equivalent of 15 Olympic-sized swimming pools — annually.

Similarly, Seattle Aquarium near Pier 66 also takes steps to eliminate its impact on the environment. Its new $170 million expansion will help reduce its freshwater and saltwater consumption and become a zero-waste operating facility.

Tim Kuniholm, senior director of Public Relations and Strategic Partnerships for the aquarium, said the expansion will also allow it to better share the message that every effort made to minimize the impact of cruising and port activity matters.

“The ocean is responsible for every breath we take,” he explained. “Without the ocean, there is no us.”

SEATTLE SAILS
Nearly 300 cruises sail out of Seattle during its cruise season, which runs from April through October. Ships depart from one of two main cruise terminals: Pier 91 and Pier 66. The larger of the two, Pier 91, offers two berths and is the home port for Carnival Cruise Line, Celebrity Cruises, Holland America Line, Princess Cruises, Cunard and Royal Caribbean. Virgin Voyages and MSC Cruises will join these at Pier 91 in 2026.

Nearby, Pier 66’s one berth serves Norwegian Cruise Line and Oceania Cruises. Most Seattle cruises typically last seven to 10 days and travel to Alaska, with popular ports of call including Ketchikan, Juneau and Skagway. While it is not uncommon to add stops at Victoria and Vancouver in British Columbia, some longer cruises visit Alaskan ports before continuing to other destinations.

For example, after visiting Alaska, the September 2026, 40-night cruise aboard Cunard’s Queen Elizabeth continues along the California coast to Mexican ports, sails through the Panama Canal and visits Caribbean destinations such as St. Maarten before ending in Miami. A few cruises skip Alaska entirely, heading to Hawai‘i, Japan, Australia or New Zealand instead. With the exception of the Hawaiian itineraries, these cruises are one-way and stop at ports in multiple countries.