New cruise ships today are twice as big as they were in 2000. If they continue to grow at this rate, the biggest ships by 2050 could be almost eight times bigger than the Titanic, says a new report by Transport & Environment (T&E).

At this size, cruise ships could amount to an eye watering 345,000 gross tonnes and carry nearly 11,000 passengers. In comparison, the RMS Titanic had 2,240 passengers and crew on board.

With bigger ships, come bigger environmental concerns and calls for green technologies to reduce their impact on the planet and local air pollution.

Majorca is already bowing under the pressure of the cruise industry. In May, it was reported that the island was considering banning large ships from visiting the island and imposing a tourist tax on passengers. Such limits have already been introduced in other popular European destinations including Santorini, Dubrovnik and Amsterdam.

Under Majorca’s current cruise rules, only three ships are allowed to visit the island each day, with only one of those permitted to carry more than 5,000 passengers. However, if Palma is going to allow ships of increasing size and capacity to enter its port, either there must be a major overhaul of its maritime infrastructure, or more extensive limits are required.

In June, the giant cruise ship, the Queen Anne, headed for Majorca on its maiden voyage. The luxury line is able to carry up to 3,000 guests, with a crew of 1,225 people. It boasts a 835-seat theatre, casino, library and art gallery, as well as a room for ballroom dancing.

Mayor Jaime Martinez proposed a ban on large ships and to only allow ships that use Majorca as their home port to visit the island. Only small medium-sized cruise ships would be allowed to dock. He also proposed a tourist tax when tourists arrive in port, with another serving as a fee to enter Palma. In April, Venice introduced a day-tripper fee of five euros, £4.30, in the hopes to discourage visitors from arriving on peak days and making the city more liveable for its dwindling number of residents.

Over the last 50 years, the global cruise industry has grown at a rapid rate, with the number of ships increasing more than twenty-fold from 21 ships in 1970 to 515 vessels today. They have also become much more of a budget-friendly holiday option, with nearly 36 million holidaymakers projected to take a cruise in 2024.

Between 2019 and 2022, the CO2 emissions from cruise ships in Europe grew by 17 percent, despite the Covid-19 pandemic, with methane emissions in particular surging by 500 percent. The world’s biggest ships - around 38 percent of global ship orders today - now run on liquefied natural gas (LNG), which, while burning more cleanly than traditional marine fuel, poses greater risks for methane emissions, said Reuters.

“Today’s cruisezillas make the Titanic look like a small fishing boat. How much bigger can these giants get? The cruise business is the fastest growing tourism sector and its emissions are quickly getting out of control,” Inesa Ulichina, sustainable shipping officer at T&E.

In January 2024, the world’s largest cruise ship so far, the Icon of the Seas, was launched. This “floating city” contains 40 restaurants, seven swimming pools and can carry 7,600 passengers. Already, it is longer than 15 blue whales and its five times bigger than the Titanic.

"The only green and scalable solution for decarbonising maritime activities is e-fuels. Cruising is a luxury business and operators must take responsibility for their climate impact. If they want to avoid becoming increasingly unwanted visitors, they must clean up their act."

A recent T&E study found that green e-fuels could power almost 4 percent of European shipping in 2030.