Shipping's Pollution Footprint: What's The Real Damage?

Shipping is a major contributor to air pollution, with ships responsible for more than 18% of nitrogen oxides pollution and 3% of greenhouse gas emissions. The environmental impact of the shipping industry is growing, and emissions are expected to increase by up to 50% by 2050 if stringent measures are not taken. Shipping vessels with engines that run on heavy fuel oil produce sulphur dioxide, nitrogen oxide, carbon monoxide, carbon dioxide, and hydrocarbons, which contribute to the formation of aerosols and secondary chemical reactions, including the formation of HCHO and ozone in the atmosphere. While shipping is the most energy-efficient way to move large volumes of cargo, the sheer size of the industry means it has a significant impact on the environment, with an annual increase in tonne-kilometers of sea shipments of 4% since the 1990s. The shipping industry is under pressure to reduce its environmental impact, with new regulations and initiatives being implemented to address air pollution from ships.

Shipping is responsible for 3% of global CO2 emissions

Shipping is a major contributor to air pollution, with exhaust gases from ships being a significant source of both conventional pollutants and greenhouse gases. While marine shipping is the most energy-efficient way to move large volumes of cargo, the sheer size of the industry means it has a notable environmental impact.

The combustion of petroleum-based fuels, such as diesel and heavy fuel oil, is the primary source of these emissions. Heavy fuel oil, commonly used in shipping vessels, has a sulphur content 2700 times higher than road fuel, leading to high levels of sulphur dioxide emissions. Diesel exhaust has been classified by the U.S. Environmental Protection Agency (EPA) as a likely human carcinogen, contributing to adverse health effects and air quality issues.

To reduce shipping's environmental impact, initiatives are being implemented to improve energy efficiency and adopt cleaner fuels. For example, Maersk, the world's largest shipping company, has ordered new container ships that will run on sustainably produced methanol. Other options include liquefied natural gas (LNG), hydrogen, and biofuels. Additionally, wind power and solar panels can be utilized to generate clean electricity for propulsion.

Regulations, such as the Prevention of Air Pollution from Ships (Annex VI), aim to control emissions and their contribution to local and global pollution. Ports are also taking action, with the Port of Vancouver offering shore power for ships, reducing air pollutants and GHG emissions.

Ships burn high-sulphur bunker oil, producing harmful sulphur dioxide

Marine shipping is the most energy-efficient way to move large volumes of cargo over long distances. However, like all other forms of transportation that burn hydrocarbon fuels, ships create air pollution that degrades air quality and adversely affects human health.

Ships burn heavy fuel oil, also known as bunker oil, which is produced through the refining of crude oil and contains high levels of sulphur. When bunker oil is burned, it releases sulphur dioxide into the air, an air pollutant that can cause respiratory problems and other health issues in humans. Sulphur dioxide is also a potent greenhouse gas that significantly contributes to global warming.

In 2005, sulphur dioxide emissions from international shipping in the seas surrounding Europe were estimated at 1.7 million tonnes per year. To address the issue of sulphur dioxide emissions, the International Maritime Organization (IMO) has implemented new regulations under MARPOL Annex VI, limiting the sulphur content of bunker fuel to 0.50% mass by mass starting from January 1, 2020. This is a significant reduction from the previous limit of 3.50% and is expected to prevent approximately 150,000 premature deaths and 7.6 million childhood asthma cases globally each year.

While the majority of ship owners are expected to switch to lower-sulphur fuels, a small percentage of ships are projected to continue burning high-sulphur bunker fuel and install scrubber systems to capture sulphur oxides and fine particulate emissions. However, there are concerns about the water pollution caused by scrubber wash-water discharges in open seas and closed-water areas.

Marine shipping produced 4.2 million tonnes of GHG emissions in Canada in 2020

Marine shipping produced 4.2 million tonnes of greenhouse gas (GHG) emissions in Canada in 2020, accounting for about 0.6% of the country's total GHG emissions. This figure highlights the significant environmental impact of the shipping industry, which is responsible for around 3% of global greenhouse gas emissions. While marine shipping is the most energy-efficient way to transport large volumes of cargo, the industry's rapid growth and substantial tax privileges have contributed to rising emissions.

The health and environmental consequences of marine shipping emissions are evident in Canada. Acidification in Canadian coastal waters damages the shells of clams and mussels, affecting a $1.3 billion aquaculture industry. It also weakens coral structures, which are important habitats for various species. Furthermore, ground-level ozone and nitrogen oxides (NOx) contribute to toxic algal blooms and decrease water oxygen levels, posing threats to marine and aquatic life.

To address these issues, regulations such as the Prevention of Air Pollution from Ships (Annex VI) aim to control emissions of SOx, NOx, ozone-depleting substances, and VOCs. The 2008 revisions to Annex VI introduced progressive reductions in global emissions of SOx and NOx, with specific emission control areas (ECAs) established in certain regions. Additionally, amendments in 2022 focused on improving operational efficiency and reporting on carbon intensity.

Some ports in Canada, such as Vancouver, have implemented shore power for ships, reducing air pollutants and GHG emissions. The Port of Vancouver's shore power connections have resulted in a significant decrease of 18,264 tonnes of GHG emissions from cruise ships and container vessels. Clear Seas, a Canadian non-profit organization, provides independent information to support informed decision-making on marine shipping issues, promoting a sustainable and inclusive marine sector.

While the COVID-19 pandemic led to a notable decrease in GHG emissions from the transport sector between 2019 and 2020, emissions increased again from 2020 to 2021 as economic activities resumed. This underscores the ongoing challenge of managing emissions and the need for further initiatives to mitigate the environmental impact of marine shipping.

Shipping is responsible for over 18% of nitrogen oxide emissions

Shipping is a major contributor to air pollution, with exhaust gases from ships being a significant source of both conventional pollutants and greenhouse gases. Shipping is responsible for more than 18% of nitrogen oxides emissions, also known as NOx emissions, which have severe environmental and health impacts.

NOx emissions from shipping activities have been estimated at 2.8 million tonnes per year in the seas surrounding Europe. These emissions contribute to an overabundance of nutrients in coastal waters and inland lakes, causing toxic algal blooms and decreasing water oxygen levels, which has detrimental effects on marine and aquatic life.

In addition, NOx emissions from ships can travel long distances inland, affecting air quality in nearby coastal communities. For example, in the Santa Barbara, California area, shipping contributes about 37% of total nitrogen oxide emissions, and this percentage is expected to increase over time. The health risks associated with exposure to NOx emissions and other pollutants from ships are significant, with diesel exhaust classified as a likely human carcinogen by the U.S. Environmental Protection Agency (EPA).

To address the issue of NOx emissions from shipping, regulations such as the Prevention of Air Pollution from Ships (Annex VI) have been implemented, which seek to control and reduce NOx emissions from ships. Additionally, the use of low-sulphur fuels, scrubbers, and alternative sources of energy such as wind power, solar power, and biofuels are being explored as potential solutions to reduce emissions and mitigate the environmental and health impacts of shipping activities.

While shipping is responsible for a significant portion of nitrogen oxide emissions, it is important to note that the industry is taking steps to reduce its environmental impact through the adoption of new technologies, fuels, and regulations. However, the cost of implementing these changes can be high, and the development of carbon-neutral or green fuels on a commercial scale is still ongoing.

Shipping industry emissions are set to increase by 50% by 2050

The shipping industry is a major contributor to air pollution, with ships responsible for more than 18% of nitrogen oxides pollution and 3% of greenhouse gas emissions. The environmental impact of the industry includes air pollution, water pollution, acoustic, and oil pollution. The sheer size of the industry means it has a significant effect on the environment.

While shipping is the most energy-efficient way to move large volumes of cargo, the annual increase in shipping overwhelms gains in efficiency. The growth in tonne-kilometers of sea shipments has averaged 4% yearly since the 1990s and has grown by a factor of 5 since the 1970s. The increasing trade between the US and China is also exacerbating environmental problems, with more vessels navigating the Pacific.

To address these issues, the International Maritime Organization (IMO), the global regulatory body for shipping, adopted the Revised Greenhouse Gas (GHG) Strategy in July 2023. This strategy sets a sectoral target of net-zero emissions by or around 2050, with indicative checkpoints for total GHG emissions reductions of 20-30% by 2030 and 70-80% by 2040. The IMO's strategy also includes mid-term measures such as a technical goal-based marine fuel standard and an economic maritime GHG emissions pricing mechanism.

The Getting to Zero Coalition, an industry-led platform, aims to make commercially viable zero-emission vessels a reality by 2030, with full decarbonization by 2050. To achieve this, the coalition estimates an investment of USD 100-150 billion is needed between 2030 and 2050 for ship engines and energy efficiency technologies. Operational and technical measures, such as speed limitation, route optimization, hull design, and engine tuning, are also being explored to reduce emissions.

While progress is being made, the shipping industry faces challenges in transitioning to zero-emission vessels. For example, new fuelling infrastructure, known as bunkering, is needed to enable the use of alternative zero-emission fuels. Additionally, regulatory attempts by the IMO may be blocked by the industry's dominant business-as-usual logic, hindering the path to decarbonization.

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