Cruise lines are making these changes to go green. Critics say more needs to be done

As cruise ships sail the seas, many are charting a new course on the environmental front.

"Cruise lines have had this label as polluters for a long time and many, many years ago they weren’t as stringent about the way they treated our oceans," Cruise Critic Editor in Chief Colleen McDaniel said.

With the push to reduce their carbon footprint, cruise companies are implementing new measures in effort to go green.

“These ships that are rolling out now are some of the most technologically advanced in terms of environmental sustainability, so what’s so fascinating is the foresight that goes into the building of the ships and the decisions that are made around the engines," explained Kelly Craighead, the President and CEO.

Experts say many ships are even equipped with waste and water treatment plants right onboard.

"It’s pretty incredible. If you actually see what goes on, on a cruise line," McDaniel said. "They treat water to the point that it could actually be potable. They don’t use it for that but they could."

Cruise lines are also teaming up with cities and local utility companies to cut their emissions when they’re docked in port. It’s called shore power, which is similar to plugging in your electric vehicle.

"The cruise lines will turn off their primary engines, and they'll plug into the local grid through FPL. This is huge," Port Miami Director and CEO Hydi Webb explained. "You're basically powering an entire city through our local grid, reducing the emissions and it's much cleaner."

Mayor Daniella Levine Cava also said Miami-Dade County is doing its part to improve conditions on the environmental front, as well.

"We're reducing our carbon output, and it's cleaner," Levine Cava said. "It's better for the environment. And it's modern."

Port Miami plans to launch shore power in spring 2024 and Port Everglades says it will have shore power up and running by 2027.

And while out at sea, some cruise lines are also shifting toward alternatives to traditional marine fuel. Liquified natural gas, also referred to as LNG, is currently a common alternative.

“You’ll hear a lot about clean burning fuel, LNG right now, but a lot of people are talking about," McDaniel said. "This is a much cleaner alternative to a lot of the fossil fuels that cruise lines would typically use.”

Port Miami's Director says it's becoming more widely used within the industry.

"Carnival Cruise Line celebration just arrived here this last year. They are LNG," Hydi Webb said. "Icon of the Seas arrival...they are being fueled by LNG. MSC’S new ship once the terminal is open, the world class will be LNG is ready."

There are concerns from some groups that LNG could emit methane, which studies show is 80 times more potent than carbon dioxide over a 20-year span. Critics worry about the affects it could have on our climate.

Climate group Nature and Biodiversity Conservation Union reports that some of the top cruise companies are currently more than 50 percent behind in their progress to reducing emissions.

The ranking is based off a company’s efficiency measures, climate protection measures and their timeline toward making their entire fleet climate neutral.

Craighead says that engines on newer ships are built to take different types of fuel, and as new sustainable marine fuels are developed, the ship will be able to use them.

She says the industry-wide goal is to achieve zero net emissions.

“The public and private sector needs to really start to understand those challenges to work together to do what each of us can uniquely do which, in the case of cruise lines, is build the ships that will be the future," Craighead said.