Freight Shipping's Pollution Problem: What's The True Cost?

The global freight shipping industry is facing increasing pressure to reduce its environmental impact. The industry contributes to up to 3% of global emissions and 10% of transport emissions, with demand for shipping expected to increase by 50-250% by 2050. The largest ships emit as much pollution as 50 million cars, and freight trucks are responsible for 7% of corporate greenhouse gas emissions. In addition to air pollution, freight shipping also causes water pollution through ballast water discharge, oil spills, and waste disposal. While some companies are investing in new technologies to reduce emissions, such as green fuels and wind energy, the shipping industry as a whole is facing challenges in its efforts to decarbonize.

Oil spills and ballast water discharge

The marine transportation of oil is particularly risky, and oil spills are a significant negative externality of the economy. Oil is toxic to marine species, and even minor spills can have significant impacts. Regular maintenance of ships and improved ship design can reduce the risk of oil spills.

Ballast water is used by cruise ships, large tankers, and bulk cargo carriers to maintain stability, draft, and manoeuvrability. This water often contains a variety of biological materials, including plants, animals, viruses, bacteria, and non-native species. When ballast water is discharged, these species can be introduced to new environments, causing ecological, economic, and public health problems. The International Maritime Organization (IMO) has developed the "International Convention for the Control and Management of Ships' Ballast Water and Sediments" to address this issue, and treatment systems can help mitigate the impact by removing or inactivating these species before discharge.

The shipping industry is facing increasing pressure to reduce pollution, with some companies committing to decarbonization and the use of green fuels. While this has been challenging due to the lack of available green fuel and the expense of new ships, some progress is being made, with major companies investing in sustainable solutions and committing to zero-emission shipping.

Greenhouse gas emissions

The shipping industry is a major contributor to global emissions, accounting for up to 3% of global emissions and 10% of transport emissions. The largest ships emit as much pollution as 50 million cars, and the demand for shipping is expected to increase by 50-250% by 2050. The industry's reliance on bunker fuel, a highly polluting and low-quality diesel, exacerbates the problem.

Freight truck movement alone is responsible for 7% of all corporate greenhouse gas emissions. Air pollution from shipping activities has severe health impacts, causing an estimated 250,000 deaths annually and contributing to 6.4 million cases of childhood asthma each year.

To address these issues, the shipping industry is facing increasing pressure to reduce emissions and transition to greener alternatives. The International Chamber of Shipping, representing 80% of the global fleet, has expressed commitment to total decarbonization by 2050. Maersk, the world's largest shipping company, is leading the way by investing in container ships powered by sustainably-produced methanol.

While some companies are taking initiative, the development of green fuel and ships has been challenging due to the chicken-and-egg situation. Additionally, resistance from shipbuilders, oil companies, and states heavily invested in the industry has hindered progress.

To reduce emissions, some shipping companies have adopted slow steaming, which involves operating ships at reduced speeds, resulting in lower fuel consumption and decreased maintenance costs. This simple measure can lead to a significant reduction in CO2 emissions, with a 10% decrease in ship speed resulting in a 27% reduction in emissions.

Air pollution and health risks

Air pollution from freight shipping has a significant impact on human health. The commercial marine shipping industry is a major contributor to global air pollution, emitting various pollutants such as greenhouse gases, nitrogen oxides (NOx), sulphur oxides (SOx), and particulate matter. These emissions have been linked to an increased risk of cancer, respiratory diseases, and heart problems, leading to premature deaths worldwide.

One of the primary concerns regarding air pollution from freight shipping is the emission of greenhouse gases, particularly carbon dioxide (CO2). Carbon dioxide is produced by burning fossil fuels and contributes to climate change by warming the atmosphere. According to estimates, the shipping industry emits about 1 billion metric tons of carbon dioxide annually, accounting for approximately 3% of global greenhouse gas emissions. The Environmental Defense Fund reports that freight truck movement alone is responsible for 7% of all corporate greenhouse gas emissions.

Nitrogen oxides (NOx) and sulphur oxides (SOx) are other significant pollutants emitted by freight ships. These pollutants are known to have detrimental effects on both human health and the environment. NOx emissions contribute to the formation of ground-level ozone, which is harmful to breathe. Additionally, NOx emissions harm marine and aquatic life by causing toxic algal blooms and decreasing water oxygen levels. SOx emissions, on the other hand, are a leading cause of acid rain, which has widespread impacts on ecosystems and infrastructure.

Particulate matter, such as diesel soot, is another toxic air pollutant released by freight ships. Diesel exhaust has been linked to the development of asthma and an increased risk of lung cancer. It is estimated that more than 125,000 Americans may develop cancer from exposure to diesel fumes. Moreover, particulate matter can lead to respiratory issues and is associated with premature deaths. According to a study, shipping-sourced emissions were projected to cause approximately 265,000 premature deaths globally in 2020.

The health risks of air pollution from freight shipping are particularly pronounced in coastal regions and along major shipping routes. Communities in these areas are directly exposed to the pollutants emitted by ships, increasing the likelihood of adverse health effects. The impact of shipping emissions on human health has been observed in various regions, including East Asia, where the growing number of trade ships has resulted in increased pollution and health risks.

Noise pollution

Commercial shipping is the primary contributor to underwater noise pollution in the ocean. A cargo vessel emits around 190 decibels of noise, which is louder than a jet engine at takeoff. Noise travels four times faster in water than in air, meaning that noise from a ship can carry exceedingly far, impacting a broad area of the ocean as it travels. The total carrying capacity of the global fleet nearly quadrupled between 1996 and 2020, and the number of vessels tripled in number while the gross tonnage of vessels increased by more than a factor of six from 1955 to 2005. This increase in shipping has caused low-frequency noise levels to rise in many oceanic locations.

The noise emitted by ships comes from various sources, including propeller cavitation, the engine, and the flow of water past the ship's hull. Propeller cavitation occurs when the rotating blades cause the local pressure in the water to drop, resulting in the formation of bubbles. This phenomenon can be mitigated through design changes to the propeller and hull or the use of devices that smooth the water flow into the propeller. For example, in 2017, Maersk modified several of its ships, resulting in a 75% reduction in noise energy emitted.

The impact of underwater noise pollution on marine life is significant. Marine animals, such as whales, fish, and lobsters, rely on sound to communicate, find food, reproduce, and navigate. When ship noise overwhelms these natural sounds, marine life may leave their preferred habitats, change important behaviours, or experience elevated stress levels, which can lower their resilience to other challenges such as water pollution and climate change. Studies have shown that noise pollution can lead to changes in the behaviour and physiology of marine mammals and directly affect their mortality rates. Additionally, the decrease in catch rates of fish species like herring, cod, and blue whiting has been attributed to noise pollution from ships.

The issue of underwater noise pollution from ships has been recognised by organisations such as the International Maritime Organization (IMO), which has adopted routing measures to protect whales and other cetaceans from ship strikes during breeding seasons. The Marine Environment Protection Committee (MEPC) has also approved guidelines for the reduction of underwater noise from commercial shipping to mitigate adverse impacts on marine life. These guidelines provide technical knowledge, recommendations, and strategies to reduce underwater radiated noise from ships.

Decarbonization and green fuel

The global shipping industry is facing increasing pressure to reduce the pollution caused by the world's merchant fleet. In 2018, global shipping activity emitted 1.05 billion tonnes of carbon dioxide, accounting for about 2.9% of global CO2 emissions. The industry is responsible for other types of pollution, including ballast water, biocides, waste, and oil spills, which have disastrous effects on ocean ecosystems.

To address this issue, the shipping industry is committed to total decarbonization by 2050. This involves a transition to carbon-neutral or green fuel. However, as of 2021, green fuel has not been developed on a commercial scale, and new ships are still designed to run on oil. Despite this challenge, Maersk, the world's largest shipping company, has taken a significant step towards decarbonization by ordering eight large container ships worth over a billion dollars that will run on sustainably produced methanol. Maersk aims to have at least 25% of its ocean-going cargo transported with green fuel by 2030, requiring around six million tonnes of green methanol annually.

Green methanol is a sustainable alternative to traditional marine fuels, offering a 90% reduction in greenhouse gas emissions throughout its lifecycle. It can be produced by combining captured carbon dioxide with green hydrogen through electrolysis powered by renewable energy sources. This process, known as e-methanol, results in a 94% reduction in well-to-wake emissions. Additionally, burning green methanol eliminates pollutants such as sulphur dioxide and particulates, while reducing nitrous oxide emissions by approximately 80%.

While the development and adoption of green fuels in the shipping industry is still in its early stages, there is a growing sense of urgency to meet decarbonization targets. Large multinational organizations aim to reduce emissions from shipping by 50% in the coming years, and influential retail giants like Amazon, Ikea, Walmart, and Target are committed to zero-emission shipping by 2040. These efforts are crucial in reducing the environmental impact of freight shipping and contributing to global sustainability goals.

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