Chances are, almost everything you own and much of what you ate today spent some time on a ship. 90% of all goods travel on ships. Roughly 100,000 ships are loading up or crossing the ocean at any given time, providing a lifeline for islands and coastal communities and making the global economy possible.
But every year, ships generate about a billion tons of CO2, kill an estimated 20,000 whales and make so much noise that sea creatures can’t use their sonar to find each other to migrate, mate or hunt. Sustainable shipping is an effort to make shipping less toxic for the ocean.
The Biggest Challenge: Sustainable Shipping Fuels
The biggest sustainability problem for ships is the emissions they create with fossil fuels. Most of the maritime industry’s greenhouse gas (GHG) emissions come from dry bulk ships, which carry unpackaged items like iron ore, coal and grain, and from container ships that bring furniture, clothing, and electrical appliances or parts.
Some companies are trying to replace these ships with new, high-tech sailing ships or electric ships. But more commonly, shippers are trying to transition from fossil fuels to more sustainable fuels like biomethanol, biodiesel and hydrogen—made using renewable energy–that could reduce shipping emissions by up to 90%. Many companies are in the process of transitioning, since regulations from the International Maritime Organization and countries and regions like the European Union make it imperative for shippers to reduce their emissions.
Starting in 2025, the EU mandated that the maritime industry join the aviation industry in the EU’s Emissions Trading System (ETS). This requires some shipping companies to purchase and use EU ETS emission allowances for each ton of reported CO2 or equivalent. So it becomes costly to emit CO2. In 2025, ships must cover 40% of their emissions through the ETS system, with the amount gradually increasing to 100% in 2027. This only applies to tank-to-wake emissions, however: the emissions that occur from the time they take fuel on board. A new regulation that came online in 2025 was FuelEU which covers well-to-wake emissions–all the greenhouse gas emissions attributable to the ship including fuel production. That’s why it matters what sustainable fuel shippers choose.
FuelEU requires a 2% reduction in lifecycle GHG emissions in 2025, increasing to 80% in 2050.
Transitioning to sustainable fuels also helps the industry’s customers who have to meet their own emissions reduction targets. One group of retailers, including Amazon and Patagonia, announced in November that they were looking for a shipping partner for several years starting 2025. But they only wanted to work with companies that could offer zero-emission shipping. If consumer goods companies and retailers can show regulators that they reduced their companies’ Scope 3 emissions–emissions that come from their supply chains–by paying extra for zero-emission shipping, it helps them meet CO2 reduction targets. Scope 3 are considered the toughest targets to hit.
But transitioning from fossil fuels to sustainable fuels is a huge undertaking. First, shipping companies have to decide which fuel they’re going to go with. This is difficult, because no fuel has emerged as the leader, although a lot of experts predict that hydrogen and biofuels will probably be the most successful.
Then shipping companies have to spend billions to either retrofit old ships or build new ships to be able to carry (bunker in shipping terminology) and use these new fuels. Many companies are making those investments, but they’re building ships that can burn both conventional fuels and sustainable fuels, because they can’t always get their hands on sustainable fuels.
Part of the challenge is incentivizing fuel companies to pivot to creating these fuels. Many fuel companies lack a supply chain for the feedstock, which may include hydrogen, captured CO2, agriculture waste and other products. They don’t always have access to renewable energy. And these sustainable fuels currently cost about four times more than conventional fuels. So If fuel companies are going to make them, they want to know that shippers have committed to buying them in large volume.
Plus a lot of ports have no way of distributing the fuels. If a ship pulls into a port that can’t provide its hydrogen or biofuel, the ship will wind up refueling on heavy fuel oil or another conventional fuel.
Finally, the fuels need to be certified as sustainable. The International Sustainability and Carbon Certification (ISCC) has issued a framework to provide ‘Proof of Compliance’ (PoC) for the use of low-emission fuels in the maritime sectors, which will help validate the sustainability of fuels. Other companies are running tests to determine exact emissions numbers.
Efforts to Support the Sustainable Shipping Fuel Market
Fortunately, in 2024 many organizations stepped forward with solutions to help promote the sustainable shipping fuel market. The Mærsk Mc-Kinney Møller Center for Zero Carbon Shipping (MMMCZCS) and RMI introduced a book-and-claim system. This system has been instrumental in increasing the use of sustainable fuels in the aviation industry.
With book-and-claim, one shipping company can buy fuel for another and then claim the carbon credits. So if Acme Shipping Company can’t get hold of sustainable shipping fuel, it can buy the fuel for a different company that does have access to the fuel. Then it can claim the carbon credits. This system helps build the market for sustainable shipping fuels and lets Acme become part of the solution.
Another major effort to promote the sustainable maritime industry is the proliferation of “green corridors” (though blue corridors might be more appropriate). Some ports, like the Yokohama Port in Japan, the Port of Rotterdam and the Port of Los Angeles, are committed to making more sustainable fuels available. And special shipping lanes are being designated between such ports to ensure ships can travel those routes using sustainable fuels. Some 50 green corridors are planned and the number keeps growing.
Shipping That Protects Sea Life
But sustainability isn’t just about the fuel. Experiments have shown that sea animals can’t function normally in a noisy ocean. They can’t find food to hunt, can’t breed, can’t socialize normally. And tens of thousands of whales and cetaceans are killed every year by ships. The mass killing of animals for shipping is bad enough on its face. But it’s also bad for the environment. The ocean is the world’s largest carbon sink. And according to the International Monetary Fund, each great whale sequesters 33 tons of CO2 on average. When they die, that carbon is removed from the atmosphere for centuries. But if they are killed prematurely, that significantly reduces the amount of carbon they can sequester.
The International Fund for Animal Welfare demonstrates that if ships slow down to 75% of their normal speed, it could dramatically reduce the noise level and the numbers of whales killed. The group’s Blue Speeds website shows the difference in the decibel levels at slower speeds. Ships can also use emerging technologies to route shipping around predictable migration patterns and hotspots for cetaceans like Blue Whales and endangered North Atlantic Right Whales.
But for ships to be willing to take longer routes, slow down, and make other changes, the companies and the final customers have to be willing to accept slower deliveries.
Surveys show customers would wait one day for sustainable shipping but not three days.
However, most consumers probably don’t understand how waiting a couple of days could make a difference. Waiting a couple more days might mean the company can wait for delivery of a sustainable fuel. Or it might mean the ship will slow down, which will burn less fuel and make significantly less noise, restoring some of the ocean’s quiet. Or it might mean the ship will be able to take a longer route where it’s less likely to kill a whale.
Other Efforts for Sustainable Shipping
There are several other efforts to make shipping more sustainable.
- More companies are trying to recycle ships and reuse component parts rather than just scrapping them.
- More ports are trying to provide electricity to fuel ships while they’re in port, so they don’t have to burn fossil fuels.
- More companies are providing technologies to increase efficiency and map the best routes to reduce fuel consumption of any kind.
There is still a long way to go. BlueEconomyNews.Earth will cover developments in sustainable shipping as they develop.
