Cargo ships carry more goods per square meter around the world than any other method of transportation. The fishing and tourism industries have also taken advantage of modern advances in maritime engineering and materials to create fleets of enormous ships.

Unfortunately, these large ships also carry hazardous side-effects to sea: They guzzle fuel oil and create massive amounts of air pollution, including greenhouse gas emissions. A 2008 Organization for Economic Cooperation and Development meta-analysis of studies on maritime industry emissions found that large ocean-going vessels account for roughly a tenth of the world’s human-caused nitrogen oxides, which like carbon dioxide contribute to climate change.

Transoceanic ship traffic, particularly commercial shipping, is also creating an awful lot of sound pollution underwater. Scientific studies have shown that this growing din has disrupted communications among whales and other marine mammals. The extreme noise created by sonar and seismic testing can injure marine mammals and other marine species, sometimes leading to mass stranding events. Evidence is growing that undersea noise pollution is affecting the abilities of some fish species to evade predators, as well.

The shipbuilding industry has begun to take notice of these and other sustainability problems. A partnership between the European Investment Bank and the French government raised $160 million for sustainable shipbuilding in the past year. Norway, which has a prominent position in the European shipbuilding industry, has taken a leading role in sustainability research and development.

Here are three exciting examples of maritime design that may send shock waves through the shipbuilding industry in the next few years. One is already sailing the seas, one is about to launch, and another is aiming to set sail by 2020:

The Viking Grace
The cruise ferry Viking Grace, constructed for and operated by the Finnish company Viking Line, launched in 2013, and is among the latest examples of sustainable large ships. Unlike conventional cruise ships, which run primarily on heavy fuel oil (also called bunker fuel) for power, the Viking Grace can also burn liquefied natural gas (LNG), which significantly reduces greenhouse gas emissions as well as particle pollution, and cuts sulfur oxide emissions nearly completely.

In January, Viking Line recently announced plans to fit the Viking Grace with an advanced form of sail, making it the world’s first hybrid-powered cruise ship. The sail will reportedly cut the cruise ship’s annual carbon emissions by 900 tons.

The Viking Grace also recycles excess heat from its engines into electricity, and its hull is designed in such a way that it minimises wave creation, which lessens the impacts of the ship’s operations on the small islands and docked vessels along its route between Stockholm, Sweden and Turku, Finland.  The soundproofing built into the ship makes it very quiet compared to older vessels.

Energy Observer
The France-based Energy Observer, a recycled racing catamaran, intends to set off this summer on a 6-year, 50-country voyage to raise awareness for climate change, and contribute to scientific knowledge.

Energy Observer is making an even bigger break from shipbuilding traditions than the Viking Grace when it comes to fuel, however: It is apparently the world’s first hydrogen-powered vessel. The project’s research goal is to find a way to energy-efficiently convert seawater to hydrogen fuel while at sea, creating an “autonomous” power source that could theoretically transform maritime shipping, tourism, and fishing.

Peace Boat – The Ecoship Project
The Japanese NGO Peace Boat announced plans to build the world’s most ecofriendly cruise ship during the 2015 Paris climate conference. To significantly lower air pollution compared to conventional cruise ships, the design calls for using ten wind turbines, ten sails with solar panels, and a huge field of on-board solar panels to power the ship.

Plans for the Ecoship, which would have a capacity of about 6,000 passengers a year, also include closed-loop systems that would re-utilize waste products created by the ship’s operations, from oil sludge to organic wastes. Gray water would be used in a garden where food is grown for passengers, for example, while kitchen compost would become feedstock for biofuel.

In addition to pioneering clean energy and closed loop systems at sea, Peace Boat also intend for the Ecoship to “create awareness and encourage active engagement with the challenges embodied in the Sustainable Development Goals (SDGs),” as an example for other shipbuilders as well as a research centre focused on the ocean and climate change.

Peace Boat hopes to launch the Ecoship in 2020.