The decarbonization of shipping is an ongoing goal to reduce

greenhouse gas emissions from shipping A greenhouse is a structure that is designed to regulate the temperature and humidity of the environment inside. There are different types of greenhouses, but they all have large areas covered with transparent materials that let sunlight pass an ...

to net-zero by or around 2050, championed by the

International Maritime Organization The International Maritime Organization (IMO; ; ) is a List of specialized agencies of the United Nations, specialized agency of the United Nations responsible for regulating maritime transport. The IMO was established following agreement at a ...

(IMO). The IMO has an initial strategy that includes lowering, or limiting, the combustion of

fossil fuels A fossil fuel is a flammable carbon compound- or hydrocarbon-containing material formed naturally in the Earth's crust from the buried remains of prehistoric organisms (animals, plants or microplanktons), a process that occurs within geologica ...

for power and propulsion to limit emission of

carbon dioxide Carbon dioxide is a chemical compound with the chemical formula . It is made up of molecules that each have one carbon atom covalent bond, covalently double bonded to two oxygen atoms. It is found in a gas state at room temperature and at norma ...

(); development of alternative fuels such as

green ammonia Ammonia is an inorganic chemical compound of nitrogen and hydrogen with the formula . A stable binary hydride and the simplest pnictogen hydride, ammonia is a colourless gas with a distinctive pungent smell. It is widely used in fertilizers, ...

hydrogen Hydrogen is a chemical element; it has chemical symbol, symbol H and atomic number 1. It is the lightest and abundance of the chemical elements, most abundant chemical element in the universe, constituting about 75% of all baryon, normal matter ...

, and

biofuels Biofuel is a fuel that is produced over a short time span from biomass, rather than by the very slow natural processes involved in the formation of fossil fuels such as oil. Biofuel can be produced from plants or from agricultural, domestic ...

to reduce reliance on fossil fuels, and adopting digital technologies to increase vessel efficiency; and reducing emissions by 40% by 2030. In July 2023, the IMO set a series of non-binding targets for cutting emissions, marking a significant step forward from the earlier 2018 plan. These targets, however, still fall short of complete alignment with the 2015

Paris Agreement The Paris Agreement (also called the Paris Accords or Paris Climate Accords) is an international treaty on climate change that was signed in 2016. The treaty covers climate change mitigation, adaptation, and finance. The Paris Agreement was ...

goal of limiting global warming to 1.5 degrees Celsius above pre-industrial levels. The IMO is also developing new regulations aiming to reduce the

greenhouse gas Greenhouse gases (GHGs) are the gases in the atmosphere that raise the surface temperature of planets such as the Earth. Unlike other gases, greenhouse gases absorb the radiations that a planet emits, resulting in the greenhouse effect. T ...

(GHG) intensity of ship fuel and is planning to implement the world’s first global, mandatory charge on GHG emissions by 2027. This charge is intended to incentivize the reduction of emissions across the global fleet.

Background

International trade of goods is primarily sea-based, followed by

pipeline A pipeline is a system of Pipe (fluid conveyance), pipes for long-distance transportation of a liquid or gas, typically to a market area for consumption. The latest data from 2014 gives a total of slightly less than of pipeline in 120 countries ...

air An atmosphere () is a layer of gases that envelop an astronomical object, held in place by the gravity of the object. A planet retains an atmosphere when the gravity is great and the temperature of the atmosphere is low. A stellar atmosph ...

, and then

rail Rail or rails may refer to: Rail transport *Rail transport and related matters *Railway track or railway lines, the running surface of a railway Arts and media Film * ''Rails'' (film), a 1929 Italian film by Mario Camerini * ''Rail'' (1967 fil ...

truck A truck or lorry is a motor vehicle designed to transport freight, carry specialized payloads, or perform other utilitarian work. Trucks vary greatly in size, power, and configuration, but the vast majority feature body-on-frame construct ...

. Most sea vessels that transport goods use

diesel Diesel may refer to: * Diesel engine, an internal combustion engine where ignition is caused by compression * Diesel fuel, a liquid fuel used in diesel engines * Diesel locomotive, a railway locomotive in which the prime mover is a diesel engine ...

fuel oil Fuel oil is any of various fractions obtained from the distillation of petroleum (crude oil). Such oils include distillates (the lighter fractions) and residues (the heavier fractions). Fuel oils include heavy fuel oil (bunker fuel), marine f ...

, generating carbon dioxide. The maritime shipping industry transported almost 11 billion metric tonnes of cargo in 2022, which accounts for nearly 3% of global

carbon dioxide emissions Greenhouse gas (GHG) emissions from human activities intensify the greenhouse effect. This contributes to climate change. Carbon dioxide (), from burning fossil fuels such as coal, oil, and natural gas, is the main cause of climate change. The ...

. These emissions and potential oil spills can pose chronic risks to coastal regions, marine life, and ultimately ocean health in terms of pH and ecological diversity. A decrease in pH would make the oceans more acidic, lower free

carbonates A carbonate is a salt of carbonic acid, (), characterized by the presence of the carbonate ion, a polyatomic ion with the formula . The word "carbonate" may also refer to a carbonate ester, an organic compound containing the carbonate group . ...

(which are a component of shellfish and corals exoskeletons/scaffolds), and decrease conversion to carbonates. These are some of the

environmental effects of shipping Environment most often refers to: __NOTOC__ * Natural environment, referring respectively to all living and non-living things occurring naturally and the physical and biological factors along with their chemical interactions that affect an organism ...

Issue

Since marine shipping moves nearly 80% of goods by tonnage and the trend of shipping is expected to double and may triple by 2050, decarbonization strategies are critical in tackling

global warming Present-day climate change includes both global warming—the ongoing increase in global average temperature—and its wider effects on Earth's climate system. Climate change in a broader sense also includes previous long-term changes ...

and marine health. Many major shipping entities have pledged to cut carbon emissions with the goal of carbon neutrality by 2050. An industry forum called the "Getting to Zero Coalition" has set a goal of carbon neutrality by 2030, which cannot be met by a single approach. In 2021 the

Center for Strategic and International Studies The Center for Strategic and International Studies (CSIS) is an American think tank based in Washington, D.C. From its founding in 1962 until 1987, it was an affiliate of Georgetown University, initially named the Center for Strategic and Inte ...

stated that governments and shipping industry leaders, such as

Maersk (), usually known simply as Maersk ( ), is a Danish Freight transport, shipping and logistics company founded in 1904 by Arnold Peter Møller and his father Peter Mærsk Møller. Maersk's business activities include Port operator, port operat ...

Mediterranean Shipping Company Mediterranean Shipping Company S.A., branded as MSC, is an international shipping line founded by Gianluigi Aponte in Italy in 1970. The company is owned by the Aponte family with its headquarters in Geneva, Switzerland, since 1978. It is the ...

, and France’s

CMA CGM The Compagnie maritime d'affrètement - Compagnie générale maritime or CMA CGM is a French shipping and logistics company founded in 1978 by Jacques Saadé. The name is an acronym of two predecessor companies, Compagnie Maritime d'Affrètemen ...

"have shown interest in decarbonization projects." In 2021 the

European Union The European Union (EU) is a supranational union, supranational political union, political and economic union of Member state of the European Union, member states that are Geography of the European Union, located primarily in Europe. The u ...

(EU) signaled "strong policy support for maritime decarbonization through their ‘Fit For 55’ (FF55) proposal, a package of 14 legislative proposals." Groups that represent more than 90% of the global shipping industry have called for a globally applicable

carbon tax A carbon tax is a tax levied on the carbon emissions from producing goods and services. Carbon taxes are intended to make visible the hidden Social cost of carbon, social costs of carbon emissions. They are designed to reduce greenhouse gas emis ...

on the shipping industry's emissions, in order to provide financial incentives for implementation of new technologies, and provide necessary funding for research and development. A 2021 article states that extensive research and development is needed, as well as retrofitting and operational changes. The rapidly changing industry response to decarbonization can be monitored in a weekly newsletter, several conferences, and a two day overview online course. "Delay beyond 2023 would mean the future transition for international shipping is too rapid to be feasible," says

Alice Larkin Alice Larkin (previous married name Bows) is a British climate scientist. She serves as Professor of Climate Science and Energy Policy in the School of Engineering at the University of Manchester. She works on carbon budgets, international trans ...

. "It has to be all hands on deck for international shipping now.”

Proposed solutions

Various approaches have been proposed or implemented, such as the use of low carbon feedstocks (

methanol Methanol (also called methyl alcohol and wood spirit, amongst other names) is an organic chemical compound and the simplest aliphatic Alcohol (chemistry), alcohol, with the chemical formula (a methyl group linked to a hydroxyl group, often ab ...

ammonia Ammonia is an inorganic chemical compound of nitrogen and hydrogen with the chemical formula, formula . A Binary compounds of hydrogen, stable binary hydride and the simplest pnictogen hydride, ammonia is a colourless gas with a distinctive pu ...

) or

and

electrification Electrification is the process of powering by electricity and, in many contexts, the introduction of such power by changing over from an earlier power source. In the context of history of technology and economic development, electrification refe ...

with energy storage, construction of ships with lighter materials with high

tensile strength Ultimate tensile strength (also called UTS, tensile strength, TS, ultimate strength or F_\text in notation) is the maximum stress that a material can withstand while being stretched or pulled before breaking. In brittle materials, the ultimate ...

, and digital operations for enhanced transport efficiency and

container ship A container ship (also called boxship or spelled containership) is a cargo ship that carries all of its load in truck-size intermodal containers, in a technique called containerization. Container ships are a common means of commercial intermodal ...

packing. Some ships are partially automated with a skeleton crew to reduce the potential for human error, using

telemetry Telemetry is the in situ collection of measurements or other data at remote points and their automatic transmission to receiving equipment (telecommunication) for monitoring. The word is derived from the Greek roots ''tele'', 'far off', an ...

based on ship onboard sensors,

cloud computing Cloud computing is "a paradigm for enabling network access to a scalable and elastic pool of shareable physical or virtual resources with self-service provisioning and administration on-demand," according to International Organization for ...

, and

machine learning Machine learning (ML) is a field of study in artificial intelligence concerned with the development and study of Computational statistics, statistical algorithms that can learn from data and generalise to unseen data, and thus perform Task ( ...

or neural network-based decision-making. In larger shipping operations, a

digital twin A digital twin is a digital model of an intended or actual real-world physical product, system, or process (a ''physical twin'') that serves as a digital counterpart of it for purposes such as simulation, integration, testing, monitoring, and m ...

is created to simulate the trajectory based on real data from the actual ship, allowing operational managers to predict future scenarios and make decisions. These tools must be transparent yet safe to avoid hijacking and interference with other ships or transport, while also being low-cost for most operators to deploy and maintain. Electric ships are useful for short trips. ''Sparky'', an "all-electric 70 tonne bollard pull harbor

tugboat A tugboat or tug is a marine vessel that manoeuvres other vessels by pushing or pulling them, with direct contact or a tow line. These boats typically tug ships in circumstances where they cannot or should not move under their own power, suc ...

", is "the first e-tug of its type in the world." ''Sparky'' was christened in

Auckland Auckland ( ; ) is a large metropolitan city in the North Island of New Zealand. It has an urban population of about It is located in the greater Auckland Region, the area governed by Auckland Council, which includes outlying rural areas and ...

in August 2022. The world's first hybrid tugboat, the

Foss Free and open-source software (FOSS) is software available under a license that grants users the right to use, modify, and distribute the software modified or not to everyone free of charge. FOSS is an inclusive umbrella term encompassing free ...

tug ''Carolyn Dorothy,'' began operation in 2009 in the

Port of Los Angeles The Port of Los Angeles is a seaport managed by the Los Angeles Harbor Department, a unit of the Los Angeles, City of Los Angeles. It occupies of land and water with of waterfront and adjoins the separate Port of Long Beach. Promoted as "Amer ...

and the

Port of Long Beach The Port of Long Beach, administered as the Harbor Department of the City of Long Beach, is a container port in the United States, which adjoins Port of Los Angeles. Acting as a major gateway for US–Asian trade, the port occupies of land wi ...

. The tour boat ''Kvitbjørn'', ("polar bear"), operates in

Svalbard Svalbard ( , ), previously known as Spitsbergen or Spitzbergen, is a Norway, Norwegian archipelago that lies at the convergence of the Arctic Ocean with the Atlantic Ocean. North of continental Europe, mainland Europe, it lies about midway be ...

, just a few hundred miles from the North Pole, piloting a newly developed

Volvo Penta Volvo Penta is a Sweden, Swedish marine and industrial engine manufacturer, a joint stock company within the Volvo, Volvo Group. Volvo Penta evolved from a foundry in Skövde 1907, when the first marine automobile engine, marine engine, the B ...

hybrid-electric propulsion system. In June 2022, the Danish electric

ferry A ferry is a boat or ship that transports passengers, and occasionally vehicles and cargo, across a body of water. A small passenger ferry with multiple stops, like those in Venice, Italy, is sometimes referred to as a water taxi or water bus ...

''Ellen'' made a record 90 km voyage on a single charge.

Net zero Global net-zero emissions is reached when greenhouse gas emissions and removals due to human activities are in balance. It is often called simply net zero. ''Emissions'' can refer to all greenhouse gases or only carbon dioxide (). Reaching net ze ...

fuels could be used, for example in

or hydrogen-powered ships.

Green hydrogen Green hydrogen (GH2 or GH2) is hydrogen produced by the electrolysis of water, using renewable electricity. Production of green hydrogen causes significantly lower greenhouse gas emissions than production of grey hydrogen, which is derived fr ...

and ammonia produced from zero-carbon electricity (solar or wind power), are "the most promising options ... to decarbonize shipping" in 2022, according to the World Bank.

Biofuel Biofuel is a fuel that is produced over a short time span from Biomass (energy), biomass, rather than by the very slow natural processes involved in the formation of fossil fuels such as oil. Biofuel can be produced from plants or from agricu ...

s can be net-zero fuels if "the production of fuel removes a quantity of carbon dioxide from the atmosphere that is equivalent to the amount of carbon dioxide emitted during combustion." On July 21, 2022, Carnival's AIDAprima "became the first larger scale cruise ship to be bunkered with a blend of marine biofuel ... made from 100% sustainable raw materials such as waste

cooking oil Cooking oil (also known as edible oil) is a plant or animal liquid fat used in frying, baking, and other types of cooking. Oil allows higher cooking temperatures than water, making cooking faster and more flavorful, while likewise distributing h ...

, and marine gas oil (MGO)." As of April 2022, "ammonia,

and

methane Methane ( , ) is a chemical compound with the chemical formula (one carbon atom bonded to four hydrogen atoms). It is a group-14 hydride, the simplest alkane, and the main constituent of natural gas. The abundance of methane on Earth makes ...

are viable deep sea shipping fuels, while compressed and liquid hydrogen are not", according to a

World Economic Forum The World Economic Forum (WEF) is an international non-governmental organization, international advocacy non-governmental organization and think tank, based in Cologny, Canton of Geneva, Switzerland. It was founded on 24 January 1971 by German ...

article. The world's first hydrogen-powered

was launched in May 2022, at the Astilleros Armon shipyard in Navia, Spain, and is scheduled to enter service in the Port of Antwerp-Bruges in December 2022. Dual fuels engines, fuel storage options, and retrofit readiness are important to ensure adaptability. Stena was the first shipowner in the world to retrofit a large vessel for methanol, converting its

ro-pax Roll-on/roll-off (RORO or ro-ro) ships are cargo ships designed to carry wheeled cargo, such as cars, motorcycles, trucks, semi-trailer trucks, buses, Trailer (vehicle), trailers, and railroad cars, that are driven on and off the ship on their ...

'' Stena Germanica'' in 2015. Stena is partnering with methanol producer Proman and with MAN Energy Solutions to retrofit engines for dual-fuel operation on diesel and methanol.

Wind power Wind power is the use of wind energy to generate useful work. Historically, wind power was used by sails, windmills and windpumps, but today it is mostly used to generate electricity. This article deals only with wind power for electricity ge ...

is a traditional choice for shipping.

Wallenius Marine Wallenius Marine is a ship design and ship management company in Sweden. Headquartered in Stockholm, the company has additional offices in Singapore and employs some 800 people. The company was spun off from Wallenius Lines in 2003 to focus on sh ...

is developing the

Oceanbird Oceanbird is a concept for wind-powered cargo vessels under development by Wallenius Marine. The concept aims to lower emissions by up to 90 percent and the design was developed in collaboration with KTH Royal Institute of Technology and Swed ...

, a

cargo ship A cargo ship or freighter is a merchant ship that carries cargo, goods, and materials from one port to another. Thousands of cargo carriers ply the world's List of seas, seas and Ocean, oceans each year, handling the bulk of international trade. ...

K Line is a Japanese transportation company. It owns a fleet that includes dry cargo ships (bulk carriers), container ships, liquefied natural gas carriers, Ro-Ro ships, tankers, and container terminals. It used to be the fourteenth largest contai ...

is installing Seawing wind propulsion systems on five of its bulk carriers. The

kite A kite is a tethered heavier than air flight, heavier-than-air craft with wing surfaces that react against the air to create Lift (force), lift and Drag (physics), drag forces. A kite consists of wings, tethers and anchors. Kites often have ...

parafoil A parafoil is a nonrigid (textile) airfoil with an aerodynamic cell structure which is inflated by the wind. Ram-air inflation forces the parafoil into a classic wing cross-section. Parafoils are most commonly constructed out of ripstop nylon. T ...

s, which fly about 300 meters above the sea level, are estimated to reduce emissions by about 20%.

Nuclear marine propulsion Nuclear marine propulsion is Marine propulsion, propulsion of a ship or submarine with heat provided by a nuclear reactor. The power plant heats water to produce steam for a turbine used to turn the ship's propeller through a Transmission (mechani ...

has been suggested to be the only long-proven and scalable propulsion technology that produces practically zero greenhouse gas emissions.

Small modular reactor The small modular reactor (SMR) is a class of small nuclear fission reactor, designed to be built in a factory, shipped to operational sites for installation, and then used to power buildings or other commercial operations. The term SMR refers t ...

s for shipping are being investigated in South Korea. The

European Investment Bank The European Investment Bank (EIB) is the European Union's investment bank and is owned by the 27 member states. It is the largest multilateral financial institution in the world. The EIB finances and invests both through equity and debt sol ...

invests in port infrastructure to improve sustainability and reduce global transport chain emissions, including efforts that mitigate pollution from moored ships, such as shoreside electricity and ship garbage receiving facilities. Between 2018 and 2022, the Bank funded €1.3 billion on ports.{{Cite web , last=Kwasniok , first=Ronja , date=1921-09-29 , title=European Investment Bank (EIB) , url=https://changing-transport.org/european-investment-bank-eib/ , access-date=2023-08-24 , website=Changing Transport , language=en-US

References

External links

Maersk Mc-Kinney Møller Center for Zero Carbon Shipping

Zero Carbon in Shipping with OCC
International water transport Greenhouse gas emissions Fossil fuel phase-out Climate change mitigation