When the Wind Hunter, a new cargo ship in development in Japan, begins to sail, more than a dozen massive sails will help it run on wind power. Under the water, large turbines will generate electricity that can be used to make hydrogen on board, so whenever the wind stops blowing, the ship can run on zero-emissions hydrogen fuel.
The ship is one of multiple new vessels aiming to transform the carbon footprint of shipping. The cargo ships that carry sneakers and cars and bananas across the ocean—sometimes making absurdly long journeys, taking fish caught in Scotland to China to be filleted, and then back to Scotland to be sold “locally”—are responsible for around 3% of global emissions. (If shipping was a country, it would be the sixth most polluting nation in the world, ahead of Germany.)
The industry has made fast transitions in the past; in the early 1900s, the report says, ships shifted from coal to diesel in a decade or two. Now, it’s likely that multiple technologies will be used at once. Some ships are likely to run on green hydrogen, which is made from splitting water with renewable electricity. Some will run on hydrogen fuel cells. Some smaller ships are beginning to test green ammonia, made from air, water, and renewable energy, which is easier to make and store than hydrogen. Electric batteries can’t store enough power for huge ships, but can provide auxiliary power. On some windy routes, smaller ships are returning to more traditional sails.
If companies are willing to accept slightly slower shipments, that will also make it easier to use wind power and save fuel. Already, it’s common for shipments to speed to their destinations and then wait. A ship “could sit there for three weeks and not be unloaded,” says Allwright. “So you’ve rushed across the ocean, burned hundreds of tons of fuel per day, to sit there for a week waiting for a slot to come up to unload.” More customers now are trying to cut their own emissions, and accept different delivery times as they understand the climate benefits. Other tweaks to ship design and operation can also help reduce the amount of energy needed, including coatings and air bubbles that help the hull glide through water more smoothly.
Advocates want the U.S. to set a clean ship standard for every ship coming to American ports, with a 50% required cut in emissions by 2025, followed by 80% in 2030, and zero-emissions in 2035. The changes wouldn’t just have a climate benefit; air pollution in communities near ports is a major health problem. “This is also, among other things, an environmental justice issue,” says Hubbell. “Things like bunker fuel produce an inordinate amount of particulates, sulfur, and Nitrogen Oxide (NOx) pollution, all of which disproportionately, at least here in the United States, affect low-income communities and communities of color.”