Large container ships in operation at Yangshan Port in Shanghai, which saw record high capacity in January 2022 Credit - Lu Hongjie—Costfoto/Future Publishing/Getty Images
Container ships transport just about everything. The world wants more of all of it. So the ships are getting bigger, as are the shipping channels, port complexes, and loading cranes. “All over the world they’re expanding and expanding, and building more and more terminals to accommodate more and more vessels,” says Captain Erduan Murtaza, speaking on the bridge of his nearly 10 million cu. ft. container ship, the Gerda Maersk. Outside the windscreens, thousands of containers, painted in dull primary colors, are stacked nine levels high on the deck. Onshore, in an Elizabeth, N.J., container terminal, many more of these steel boxes spread into the distance like disassembled pieces of a giant’s play set.
When it was built in 2009, the Gerda Maersk was one of the largest container ships in the world. It’s nearly a quarter-mile long, with a hold seven stories deep. But even this monster has been dwarfed by the industry’s expansion—it’s able to carry only half the cargo of some recently launched ships. Murtaza says the growth is only accelerating. “During this pandemic, people went crazy because they were closed inside their homes. So what do you do? You go online and start shopping,” he says. “[All that stuff] has to come through these boxes.”
Proponents of maritime shipping are fond of referring to growth in the sector as a gauge of global economic well-being. They also trumpet shipping’s environmental bona fides, citing statistics showing that oceangoing vessels are one of the most energy-efficient ways to move goods around the world. But though those ships may be less carbon-intensive than, say, cargo airplanes, they still account for almost 3% of global CO2 emissions. And it’s unclear how that might change. Where sectors like automobiles and electricity grids are relatively straightforward to convert to renewable power, the constraints of physics mean there’s currently no simple way to move millions of tons of cargo across the oceans without fossil fuels. And despite ships getting more energy-efficient in recent decades, overall emissions continue to rise as the industry expands. Last year alone, the industry’s CO2 emissions jumped nearly 5%.
Murtaza’s employer, the Danish shipping giant Maersk, says it’s investing in a solution: replacing conventional fuels with so-called green methanol, as part of a plan to reach net-zero emissions by 2040, and hopefully begin turning the global shipping industry’s emissions trajectory in the right direction.
Today, facilities around the world produce about 100 million tons of methanol annually, almost all of which is derived from fossil fuels, and much of which is used as industrial feedstock for things like plastic production. Using fossil-fuel-based methanol to power ships, as some pilot projects have done, is not much different climate-wise from simply burning the natural gas or coal it’s made from. So instead, Maersk is trying to power its ships with green methanol.
There are two versions Maersk and others in the industry are working with. The first is biomethanol, which entails extracting the molecule from biomass like crop waste. The second is electro-methanol, or e-methanol, created by combining CO2 with hydrogen produced from water using renewable electricity. These “green” forms of methanol still release CO2 when they’re burned—but in both cases, it’s the same CO2 that had already been sucked out of the atmosphere, either by plants or machines, when the methanol was produced. That means their overall contribution to a ship’s carbon footprint is far lower than using new fossil fuels pulled up out of the ground.
Between mid-2021 and early 2022, Maersk ordered 12 new cargo vessels able to run on methanol to be delivered from Hyundai Heavy Industries in Korea in 2024 and 2025. (In a pinch, they can also run on conventional fuels.) Soon after, Maersk signed deals to secure enough green methanol to start sailing them. The new vessels account for only about 2% of Maersk’s global fleet, but it’s a first step toward decarbonizing the world’s second biggest shipping company, says Morten Bo Christiansen, who leads Maersk’s climate efforts. This will mean continually replacing ships that age out of service with ones able to sail on methanol or other fossil-fuel alternatives. “It was really a chicken-and-egg type situation,” Christiansen says. “No one was building green vessels because there was no green fuel, but no one produced green fuel because there were no vessels to burn it. This for us has been an attempt to break that.”
Danish wind and solar company European Energy is one of the players slated to produce that fuel. It is constructing what’s billed as the world’s first large-scale e-methanol plant in Kasso, Denmark; Maersk will be buying half its output when production starts in the second half of 2023. The plan was the brainchild of Soren Knudsen Kær, a former engineering professor at Aalborg University, who is working with European Energy on the new facility. The goal is to help solve a crucial challenge in decarbonizing shipping: how to store large amounts of energy, transport it, and have it ready when you need it most—like in the middle of the Pacific Ocean—without using fossil fuels, which are very energy-dense, meaning they take up relatively little space and weight compared with other possible sources of power.
When it comes to storing green energy, batteries are often the most efficient approach, but they’re too bulky for use in airplanes and ships. Hydrogen is another option: producers use giant electrolyzers and renewable power to separate hydrogen from water, and then ships either burn that hydrogen directly or use fuel cells to release its stored energy. But, says Kær, hydrogen gas is hard to store and transport, because it takes a lot of energy to compress it to a manageable volume. Around 2018, Kær started developing a pilot facility that would combine large amounts of hydrogen with carbon dioxide to form e-methanol, which can store energy in liquid instead of gaseous form, meaning it doesn’t need to be transported in high-pressure tanks. A few years later, European Energy came on board to back a much larger version of the project.
Maersk isn’t the only company that’s eyeing methanol. CMA CGM, the world’s third largest container shipper, ordered six new methanol-powered container ships in June, and Swedish shipper Stena Bulk is building methanol-powered tankers with Swiss chemical company Proman. “Go back even a year and a half ago, we’d go to a shipping conference and we’d get an opportunity to present on the last panel of the final day,” says Greg Dolan, CEO of the Methanol Institute, an industry trade association. “Now there’s so much more interest in methanol. We’re getting keynote slots.”
Despite the current craze, green methanol has a long-term handicap: methanol is a carbon-based fuel, so to make it, we need a lot of carbon. Fossil fuels are a great place to find the stuff, but we’re slowly cooking the earth as we keep pulling it up from underground and adding it to the climate system in the form of new carbon dioxide. The challenge is to find carbon that’s already in circulation and won’t tip the overall carbon balance any further. That would seem simple—too much CO2 is our problem, after all—but pulling that CO2 from coal power-plant smokestacks doesn’t create a truly green process, since it would only delay that extra fossil-fuel-sourced CO2 going into the air when ships burn the methanol that was made from the pollutant. “You’re going to use the carbon one more time, but it’s still gonna end up in the atmosphere,” says Alain Goeppert, a research scientist studying methanol systems at the University of Southern California. Taking CO2 directly from the atmosphere might seem like a good idea, but such technology (usually referred to as “direct air capture”) is expensive and energy-intensive, and some experts don’t think it’ll ever be cost-effective.
Instead, the best current option is to find sources of biogenic carbon that comes from plants or animals—either biomass that can be transformed into biomethanol through chemical processes, or CO2 released from burning or fermenting plants or other organic material that can be combined with hydrogen to make e-methanol. European Energy’s e-methanol project, for instance, relies on agricultural waste like cow manure for its supply of CO2. The problem is that there aren’t enough sustainable sources of biogenic CO2 to make more than a fraction of the methanol needed to decarbonize shipping. For example, even if Europe maxed out the use of its projected biomethane—one of the best sources of biogenic CO2—it would still account for only about a fifth of its estimated 2050 shipping needs, according to Faig Abbasov, shipping program director at environmental think tank Transport & Environment. “There’s not enough cow sh-t, basically,” he says.
There are options beyond methanol that could be better for decarbonizing shipping in the long run. In some sense, hydrogen is a simpler solution, since you need it to make methanol anyway, but as Kær mentioned, it’s hard to store it. Nevertheless, some experts believe the best approach would be to try to solve that storage problem, rather than seek alternatives.
Others believe ammonia could be a good option. Like methanol, ammonia is already produced in large quantities for many industrial uses, like making fertilizer. Today most of it is derived from fossil fuels in a process that releases large amounts of CO2. But it can also be produced from renewably generated hydrogen, and solve the same energy-storage problems as methanol, but without the e-fuel’s carbon-supply limitations. Ammonia, though, can be life-threatening to humans and marine life if it leaks (methanol is toxic too, but leaks would be far less hazardous). Maersk’s Christiansen, for one, fears some ports could ban ammonia because of its toxicity. The technology for ammonia engines is also further off than for methanol. “Even if we solve all the safety and environmental challenges, it will be toward the end of the decade before we can get any ammonia out sailing,” he says. “For us that’s just too late.”
Some experts say e-methanol’s limitations mean that it is a dead end for shipping, and will only ever be useful for small corners of the industry, like in countries planning to make biofuel power plants a big part of their larger green transition, thus creating a source of biogenerated CO2 readily usable for e-methanol production. And if shippers invest in what seems like an easy fix now, instead of going all in on the more ambitious ammonia or hydrogen options, they could waste time and resources in the long run, and end up dropping an economic anchor in the form of ships reliant on methanol fuel that will get increasingly expensive as biogenic carbon gets harder to find.
For now, Christiansen thinks there’s plenty of biomass to start hauling cargo across the world’s oceans on methanol-powered ships. And though he agrees that finding biogenic CO2 in the future will be a struggle—perhaps requiring direct air capture, if the technology comes to fruition—he believes methanol is the best current option.
Despite Maersk’s moves, the truth is that international shipping writ large hasn’t really made much climate progress. Some companies have hardly done anything. Regulation is urgently needed to force an industry-wide shift, but the power to do that rests mostly in the hands of the International Maritime Organization (IMO), an insular U.N. agency known as something of an old sailors’ club. International shipping is not covered under the Paris agreement, and in the lead-up to those pivotal negotiations in 2015, the IMO’s then Secretary General Koji Sekimizu actually said shippers should not be asked to cap their emissions at all.
That said, ahead of this year’s annual climate negotiations in Egypt, some countries are making a renewed push to green shipping. On June 17, the Biden Administration announced that the U.S. and Norway will be launching a green shipping challenge at COP27. The goal, says the White House, is to encourage the industry “to come forward with concrete steps that will help put the international shipping sector on a credible pathway this decade toward full decarbonization no later than 2050.”
Scientists warn humanity must entirely zero out its emissions by 2050 to avoid the worst effects of climate change. The IMO’s current climate strategy only mandates cutting emissions in half by 2050. Environmentalists are hoping the organization will finally tighten its goals to that higher standard when the climate strategy is up for review in 2023. Observers, however, say the shipping industry and other corporate interests have a disproportionate influence over IMO policy, with some countries even appointing private-sector representatives to their delegations. “The name of the game,” says Bryan Comer, who leads the International Council on Clean Transportation’s marine program, “is delay as long as possible.” Maersk isn’t blameless in that regard; it has fought back against proposals to limit ship speeds, which would have immediate emissions benefits. (Maersk representatives say the company supported a different proposal that would reward more efficient ships; the IMO ultimately adopted a hodgepodge of measures that included aspects of both proposals.)
There may also be a deeper problem in shipping decarbonization: an implicit assumption that everything about shipping can keep getting bigger forever. Analysts have predicted international shipping will nearly triple by 2050, a possibility that some environmentalists say is simply incompatible with a livable planet. For one thing, it makes the task of cutting the industry’s environmental footprint that much harder. For another, even if you could completely decarbonize shipping fuel, it still wouldn’t account for the emissions generated by the huge amount of new materials needed to keep growing the industry: concrete for ports, steel for hulls and containers, and plastics for the endless tides of disposable consumer items that fill them. “We’ve got this huge carbon bubble: ever bigger ships, moving more [goods] around,” says Lucy Gilliam, a policy officer at Seas at Risk, a Brussels-based NGO. “Where does this stop?”
For Gilliam, the answer is clear: to cut shipping emissions, we need to cut demand for shipping overall, which means people need to stop buying things they will quickly throw away. But most people aren’t disposed to think about what their habits have to do with the growing armadas of super-size ships chugging through the world’s oceans.
“Those plug-in electric cars, they’re peanuts compared to this big boy,” says Captain Murtaza, before the Gerda steams out of New Jersey on an 11-day journey to the Suez Canal. “Of course, I’m carrying 11,000 containers at once. But still, when I’m burning, I’m burning.” He gestures toward a window and Newark Bay beyond, where more than a dozen massive ships lie anchored on any given day. “It’s not just me. Look how many we are.”
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