Air pollution from ships


       Illustration: Lars-Erik Håkansson

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Ship emissions

Ships pour out large quantities of pollutants into the air, principally in the form of sulphur and nitrogen oxides and particulate matter (PM).

The emissions from ships engaged in international trade in the seas surrounding Europe - the Baltic, the North Sea, the north-eastern part of the Atlantic, the Mediterranean and the Black Sea - are estimated to to amount to 1.6 million tonnes of sulphur dioxide and 3 million tonnes of nitrogen oxides a year in 2013.

In contrast to the progress in reducing emissions from land-based sources, shipping emissions of sulphur and nitrogen oxides have steadily been increasing over the last thirty years. While recently introduced sulphur standards at global and EU levels have halted this increasing trend for SO2-emissions (at least in the Sulphur Emission Control Areas - SECAs) in northern Europe and North America), NOx-emissions are expected to continue increasing. As a result, within ten years the NOx-emissions from international shipping around Europe is expected to equal or even surpass the total from all land-based sources in the 28 EU member states combined (see chart below).

Baseline scenario for emissions of NOx (in kilotonnes) up to 2020 from landbased sources in EU27 and from international shipping in European sea areas.

EU27 = Emissions from land-based sources in all EU countries (incl. domestic shipping).

Sea = Emissions from international shipping in European sea areas.

TSAP = Target in line with the EU Thematic Strategy on Air Pollution from September 2005.

IMO = Expected outcome from implementing MARRPOL Annex VI as revised in October 2008

For details see Air Pollution from Ships (pdf, 980 kB).

Control measures

There are however available means by which air pollutant emissions could be reduced by as much as 80-99 per cent, and very cost-effectively compared with what would have to be done to achieve similar results onshore.

Viking Line's Grace is the first large passenger ship in the world to use gas (LNG) as its primary fuel. As result, emissions into the air of SO2, NOx and PM are reduced by around 99, 85, and 85 per cent, respectively, and emissions of greenhouse gases by some 15 per cent, as compared to using marine heavy fuel oil Photo: Viking Line.

The freighter MS Cellus emits 90 per cent less NOx and 80 per cent less sulphur dioxide than an equivalent standard ship. It is equipped with an SCR flue gas emission control system and uses low-sulphur fuel oil. Photo: El Bingle CC BY-NC.

Significant health effects

Smokestack emissions from international shipping kill approximately 50,000 people a year in Europe, at an annual cost to society of more than €58 billion, according to a Danish study from 2011. The researchers used data and projections of ships’ emissions of SO2, NOx and PM for the years 2000-2020.

Through chemical reactions in the air, SO2 and NOx is converted into very small airborne particles, sulphate and nitrate aerosols. Tiny airborne particles are linked to premature deaths. The particles get into the lungs and are small enough to pass through tissues and enter the blood. They can then trigger inflammations which eventually cause heart and lung failures. Ship emissions may also contain carcinogenic particles.

Implementing the stricter ship fuel standards agreed by the International Maritime Organisation in 2008 is estimated to save up to 26,000 lives per year in the EU in 2020.

 

>> Further reading

Lower speed - less emissions. Article in Acid News 3/2015.

Ship scrubbers questioned. Article in Acid News 2/2015.

Enforcement of ship sulphur standards. Article in Acid News 1/2015.

New figures on global ship emissions. Article in Acid News 3/2014.

SCR can cut ship NOx emissions. Article in Acid News 2/2014.

Ships should use advanced emissions monitoring. Article in Acid News 1/2014.

Shipping air pollution costs €60 billion per year. Article in Acid News 3/2013.

Ship emissions down in the Baltic and North Sea. Article in Acid News 3/2013.

Shipping should cut greenhouse gases and air pollutants. Article in Acid News 2/2013.

Air pollution from ships (November 2011). A pamphlet published jointly by AirClim and five other environmental NGOs (pdf)

Cleaner ship fuels will dominate in 2020. Article in Acid News 4/2012.

Slow steaming saves money and the climate. Article in Acid News 3/2012.

Great benefits of NOx reductions in the North Sea. Article in Acid News 3/2012.

The arrival of a new EU sulphur law. Article in Acid News 2/2012.

New standards save lives. Article in Acid News 4/2011.

California rules give great benefits. Article in Acid News 3/2011.

Ship pollution causes 50,000 deaths per year. Article in Acid News 2/2011.

Avoided Global Premature Mortality Resulting from Reduction of Sulphur in Marine Fuel (January 2008). NGO submission to IMO (pdf)

Appropriate standards to reduce air pollution from ships (October 2006). NGO submission to the IMO (pdf)

International Maritime Organization. Full text of the convention and its annexes, as well as a ratification update.

The International Maritime
Organization is a UN body
for international shipping.

 

IMO MARPOL Convention

International shipping represents a substantial and growing source of emissions of air pollutants, including greenhouse gases. Emissions of air pollutants from international shipping are regulated by the International Maritime Organisation (IMO) through the Annex VI to the International Convention on the Prevention of Pollution from Ships (MARPOL), which was originally signed in September 1997 and came into force in May 2005. Annex VI set the first global standards for the sulphur content of marine fuel oils and the emissions of nitrogen oxides (NOx) from new ship engines.

However, the 1997 standards were so weak as to be hardly likely to have any appreciable effect, and in October 2008 the IMO's Marine Environment Protection Committee (MEPC) unanimously agreed to revise and strengthen the emission standards in Annex VI. The revised law entered into force on 1 July 2010.

New sulphur limits

The first global limit on sulphur in marine fuels was set at 4.5 per cent. Under the revised Annex this limit was lowered to 3.50 per cent in 2012, and it will be further strengthened to 0.50 per cent in 2020 (subject to a review in 2018). As an alternative to use low-sulphur fuels, ships are allowed to use exhaust gas cleaning systems (e.g. scrubbers) or use other methods to limit their sulphur emissions (e.g. use alternative fuels such as gas).

Emissions Control Areas

An application for designating a sea area as an Emission Control Area (ECA) must be approved by the Parties to Annex VI. ECAs may be designated for sulphur oxides (SOx) and particulate matter (PM), or nitrogen oxides (NOx), or all three types of emissions, subject to a proposal from an IMO member country.

Annex VI originally set a limit of 1.50 per cent sulphur for marine fuel oil used by ships sailing in designated Sulphur Emission Control Areas (SECAs). The revised Annex VI lowered the sulphur limit in SECAs to 1.00 per cent from July 2010 and to 0.10 per cent as from 2015.

The Baltic Sea was the first SECA to enter into force in 2006, followed by the North Sea (including the English Channel) in 2007.

In March 2010, the IMO officially designated waters extending 200 nautical miles (370 kilometres) from the coast of the United States and Canada as the first “full” ECA, i.e. covering SOx, PM and NOx. The decision entered into force from August 2011 and the stricter sulphur limits became effective from  August 2012.

Figure 1: Comparison of various fuel sulphur limits in parts per million (ppm). Please note that the upper figure of 45,000 ppm corresponds to 4.5% sulphur content, whereas the lower figure of 10 ppm for road transport fuels corresponds to a 0.001% sulphur content.

NOx emission standards

Emissions of NOx are controlled by emission standards for new ship engines. The Tier I standards apply to all new engines as from January 2000, but these are so weak that in practise they do not have any appreciable effect. The revised 2008 Annex sets new Tier II standards that apply from 2011 and will cut emission by 16-22 per cent (relative to Tier I). It also sets Tier III standards that will cut emissions from new engines by about 80 per cent (relative to Tier I), but the Tier III standards will apply only in the specially designated NOx emission control areas (NECAs).

Figure 2: MARPOL Annex VI NOx Emission Limits. For comparison, EU diesel truck emission standards are set at 0.4 g/kWh from 2013.
 

GHG emissions

The IMO has been considering how to reduce greenhouse gas (GHG) emissions from shipping since before 2000, when it received a report estimating those emissions and describing various potential measures to reduce them. So far, however, the IMO has failed to make any significant progress in talks on addressing GHG emissions from shipping. A first step in the right direction was taken in July 2011, when the IMO adopted an Energy Efficiency Design Index (EEDI) regulation which sets minimum efficiency standards for new ships built after 2013.

Global annual emissions of the main greenhouse gas carbon dioxide (CO2) from ships amounted to around 1,000 million tonnes in 2012, corresponding to three per cent of global manmade emissions. In the absence of mitigation policies, ship emissions are projected to double or even triple by 2050.

There is great potential to improve ships’ environmental performace through efficiency – a 2009 report to the IMO estimated that ship efficiency could be improved by up to 75 per cent. The use of alternative fuels (e.g. biofuels) and propulsion systems (e.g. wind and solar energy) could bring additional significant GHG reductions.

>> Further reading 

Lower speed - less emissions. Article in Acid News 3/2015.

Marshall Islands calls for cuts in shipping emissions. Article in Acid News 2/2015.

New figures on global ship emissions. Article in Acid News 3/2014.

SCR can cut ship NOx emissions. Article in Acid News 2/2014.

IMO weakens NOx rules for ships. Article in Acid News 2/2014.

Don't delay NECAs! Article in Acid News 1/2014.

Shipping air pollution costs €60 billion per year. Article in Acid News 3/2013.

Shipping should cut greenhouse gases and air pollutants. Article in Acid News 2/2013.

Air pollution from ships (November 2011). Pamphlet published jointly by AirClim and five other environmental NGOs (pdf).

Cleaner ship fuels will dominate in 2020. Article in Acid News 4/2012.

Slow steaming saves money and the climate. Article in Acid News 3/2012.

Great benefits of NOx reductions in the North Sea. Article in Acid News 3/2012.

California rules give great benefits. Article in Acid News 3/2011.

Cleaner ship fuel to save American lives. Article in Acid News 2/2009.

Shipping could profit by cutting CO2 emissions. Article in Acid News 2/2009.

Global ship emission standards adopted. Article in Acid News 4/2008.

Avoided Global Premature Mortality Resulting from Reduction of Sulphur in Marine Fuel (February 2008). NGO submission to IMO (pdf, 200 kB)

Appropriate standards to reduce air pollution from ships (October 2006). NGO submission to IMO (pdf, 54 kB)

International Maritime Organization. Full text of the convention and its annexes, as well as a ratification update.

 

EU ship policy


       Illustration: Lars-Erik Håkansson

Sulphur in marine fuels

As part of its 2002 strategy to reduce air pollution from sea-going ships, on November 2002 the Commission published a proposal for reducing the sulphur content of marine fuels. The resulting legislation (Directive 2005/33/EC) entered into force in August 2005, and largely confirms the then global standards agreed by the International Maritime Organisation (IMO) in 1997, and which entered into force in 2005.

The 2005  directive set a 1.5 per cent fuel sulphur limit for all ships in the so-called Sulphur Emission Control Areas (the Baltic Sea and the North Sea, including the English Channel) and for passenger ferries in all European sea areas. In addition, the directive requires all ships passing in European ports to use fuel with a sulphur content of 0.1 per cent or less while at berth

In July 2011, the Commission tabled a proposal to revise and strengthen the directive by incorporating the new sulphur standards adopted by the IMO in 2008. The revised sulphur directive (2012/33/EU) was adopted in October 2012. Incorporation of the IMO provisions into EU law will hopefully ensure their proper and harmonised enforcement by all EU member states, and placing the monitoring and enforcement under the EU regime should also improve the effectiveness of the IMO standards. The revised directive prescribes that the global sulphur limit of 0.50 per cent will apply in all EU sea areas by 2020, and confirms the IMO limit for Sulphur Emissions Control Areas (SECAs) of 0.10 per cent as from 2015. Over the years, several consultancy studies for the Commission have shown the large benefits of designating more European sea areas as SECAs, but there has still not been any action to this effect.

NOx emission abatement

In its’ responses to the 2002 shipping strategy and the 2005 thematic strategy on air pollution, the Council and the Parliament expressed support for Community action to reduce NOx emissions from ships. Despite the fact that ships’ NOx emissions will continue to increase even with full implementation of the IMO’s new (2008) emission standards, no such proposals have yet been presented by the Commission. While the coastline out to 200 nautical miles (370 kilometres) of the United States and Canada have been designated as a combined sulphur and NOx ECA, there are no NOx-ECAs in Europe.

The countries around the Baltic Sea as well as those around the North Sea have over the last few years carefully investigated the pros and cons of designating these two sea areas as NOx-ECAs, Their analyses show that the monetised health benefits exceed the estimated costs. So far, however, these countries have failed to submit proposals for NOx-ECA designation to the IMO.

Shore-side electricity

In May 2006, the Commission adopted the Recommendation on the promotion of shore-side electricity for use by ships at berth in EU ports. Shore-side electricity means providing electricity to ships at berth in ports from the national grid instead of ships producing electricity using their own diesel engines. This eliminates local air and noise emissions from ships' engines while at berth.

Greenhouse gases

In June 2013, the Commission published a proposal to monitor, report and verify (MRV) emissions to air from international shipping, and the new regulation was adopted in April 2015. It creates an EU-wide legal framework for collecting and publishing annual data on CO2-emissions from all large ships (over 5000 gross tons) that use EU-ports. It does not, however, require any reductions in the emissions.

>> Further reading

Lower speed - less emissions. Article in Acid News 3/2015.

Potential for shore-side electricity. Article in Acid News 2/2015.

Ship scrubbers questioned. Article in Acid News 2/2015.

Enforcement of ship sulphur standards. Article in Acid News 1/2015.

SCR can cut ship NOx emissions. Article in Acid News 2/2014.

Ships should use advanced emissions monitoring. Article in Acid News 1/2014.

Proposal not enough to meet ship CO2 target. Article in Acid News 4/2013.

Shipping air pollution costs €60 billion per year. Article in Acid News 3/2013.

Ship emissions down in the Baltic and North Sea. Article in Acid News 3/2013.

Shipping should cut greenhouse gases and air pollutants. Article in Acid News 2/2013.

Slow steaming saves money and the climate. Article in Acid News 3/2012.

Great benefits of NOx reductions in the North Sea, Article in Acid News 3/2012.

The arrival of a new EU sulphur law. Article in Acid News 2/2012.

EU moving towards stricter ship fuel standards. Article in Acid News 1/2012.

New standards save lives. Article in Acid News 4/2011.

Sulphur emissions from shipping to be slashed. Article in Acid News 3/2011.

Strict sulphur standards no threat to shipping. Article in Acid News 1/2011.

NOx emission control in the Baltic Sea. Article in Acid News 1/2011.

High benefits of ship fuel action. Article in Acid News 3/2010.

Market-based instruments for NOx abatement in the Baltic Sea (Nov 2009). AirClim Report 24. See also a summary in Acid News 4/2009.

Air pollution from ships (November 2011). A pamphlet published jointly by AirClim and five other environmental NGOs (pdf, 530 kB).

The directive on sulphur in marine fuel (2012/33/EC) (pdf)

European Commission DG Environment. An updated description of the legislation process and a number of background reports.