International shipping is growing, as are its pollutant emissions. However, regulation has proved tricky to introduce. Now the European Commission has agreed to tighten what rules are in place, and research has found the results are very positive thus far. Rob Bell reports.

Mitigation of emissions from shipping — both of air pollutants and carbon dioxide (CO2) — has proven tricky. As is the case with aviation, the international nature of the industry sector makes regulation by one nation, or by larger blocs such as the European Union, difficult.

In addition, when it comes to carbon and the role of greenhouse gases such as CO2, the industry would claim shipping is a much greener method of transportation than plane, trucking, or even rail.

However, the impacts of shipping are significant. As environmentally friendly (by comparison) as moving goods by ship may be, it is still a major source of pollution — and a growing one.

According to the European Commission’s Joint Research Centre (JRC), the estimated contribution of ships to global nitrogen oxides (NOx) emissions is around 15%, while 4–9% of sulphur dioxide (SO2) emissions can be attributed to ships.

Sulphur dioxide

Sulphur dioxide is an important air pollutant, one of the main chemicals responsible for both the formation of acid rain and of particulate air pollution, which is a major risk factor for cardiovascular and respiratory diseases.

In 2005, an amendment was made to Directive 1999/32/EC (relating to a reduction in the sulphur content of certain liquid fuels and amending Directive 93/12/EEC) that required, as of January 2010, that all ships at berth or at anchor in European harbours use fuels with a sulphur content of less than 0.1% by weight. Previously, outside of Sulphur Emission Control Areas (SECAs) — the main mechanism currently in use to address shipping emissions regulated under the International Convention for the Prevention of Pollution from Ships (MARPOL) — a sulphur content of up to 4.5% was allowed.

The Commission says: “Ships traditionally use heavy fuel oil, which, from 2012, can have a sulphur content of up to 3.5% for cargo vessels (before 2012 this limit was 4.5%). The average sulphur content of heavy fuel oil is about 2.4%. By comparison, the sulphur content of fuels used in road vehicles must not exceed 0.001%.”

Enforcing controls

This level of pollution can no longer be ignored, and steps are being taken internationally to introduce regulation with the aim of cutting pollution from the global shipping trade. Within SECAs, controls are enforced on emissions of sulphur oxide (SOx), NOx and particulate matter (PM).

The beginning of August saw the birth of the third SECA globally, with the North America Emission Control Area covering the coasts of Canada, the United States and the French overseas collectivity of Saint-Pierre and Miquelon, joining the SOx-only ECAs in the Baltic and North seas (and the English Channel).

The European Commission is particularly enthusiastic about reducing pollution from shipping, due to its impact on air quality far from ports themselves. It says: “Air pollutant emissions from maritime transport can be transported over long distances and thus increasingly contribute to air quality problems in the European Union.”

Commission research has forecast that sulphur emissions from shipping will exceed those from all land-based sources in the EU by 2020. The Commission says: “Further action is therefore needed to improve human health and the environment.”

The beginning of summer saw a step towards that further action, with an agreement by the European Commission that sets a sulphur limit of 0.5% by 2020 in all EU waters except ECAs, where a 0.1% limit will apply from 2015.

The current IMO limit for general waters is 3.5%, with an agreement to come down to 0.5% in either 2020 or 2025, depending on a review of the availability of cleaner fuels due to take place in 2018.

The European Commission says: “In line with the broader environmental protection objectives of the EU and strengthening a parallel agreement reached by the International Maritime Organisation, the European Parliament and the Council have come to an agreement to be submitted to formal vote after the summer on an amendment to the 1999/32/EC directive to further reduce sulphur content of fuels used outside of harbours.

“The maximum allowed sulphur content of ship fuels will go down from 3.5% to 0.5% in 2020, and in the Sulphur Emission Control Areas (the Baltic Sea, the North Sea and the English Channel) the current limit of 1.5% sulphur content for ship fuels will be reduced to 0.1% in 2015.”

Lobby group Transport and Environment (T&E) says the agreement boosts efforts to tackle air pollution from shipping and could reduce the sulphur content of fuel used by ships in EU waters by 85% by 2020.

T&E says: “The agreement signals an EU willingness to encourage cleaner shipping fuels more quickly than originally expected. We welcome the deal, but believe it should be the start of a broader process to improve air pollution from ships, and that enforcement measures must be tightened up.”

T&E Shipping Officer Antoine Kedzierski says: “This agreement shows both good progress and how little progress has been made to date. Switching to 0.5% sulphur fuels is an 85% improvement on current EU sulphur levels, so this would be a significant step towards reducing the 50,000 premature deaths caused by shipping air pollution in Europe every year.

“But compared to the USA and Canada, which have introduced a SECA along their entire coastline, the EU can still make more progress to further reduce harmful emissions from ships.”

Regulating emissions from dirty fuel

The European Environmental Bureau (EEB) also described the agreement as a “boost” to efforts to regulate shipping emissions. The EEB says: “The United States and Canada have led the way in cutting shipping air pollution on a continent-wide scale having already agreed to designate all sea within 370km of the North American coast as a SECA with a 0.1% limit from 2015.

“However, the EU has now sent a clear signal that it wants cleaner fuels earlier rather than later while still leaving eight years for the industry to adapt. Currently fuel used by ships in non-SECA EU waters contains on average 2.7% sulphur, so the new 0.5% limit is a very significant 85% cut.”

The EEB’s Policy Officer on Air Pollution, Louise Duprez, says: “Marine fuel is one of the dirtiest fuels around, blackening our skies and seas with every nautical mile sailed. We are pleased to see that the EU has recognised that marine fuel needs to be cleaned up; however, sulphur is only one of many pollutants in one of many polluting sectors. We urge the EU to look wider in 2013, the ‘Year of Air’ in order to trigger further improvements for people’s health and the environment.”

While stricter regulation of emissions of sulphur and other substances from shipping is on the way, the regulatory actions that have already been taken in the EU have had a significant impact, according to research carried out by the European Commission’s JRC. The JRC has published a report, titled Impact of a European Directive on Ship Emissions on Air Quality in Mediterranean Harbours, which sets out research, the results of which show SO2 emissions from shipping have sharply decreased in EU ports. The JRC says: “Scientists measured key air quality parameters in Mediterranean harbours before and after the entry into force of the low-sulphur requirements in January 2010.

“They found that in the EU harbours Civitavecchia, Savona, Barcelona and Palma de Mallorca, the concentration of SO2 had fallen by 66% on average.

“Sulphur dioxide is one of the main chemicals responsible for formation of acid rain and particulate air pollution, posing risks to health and the environment. Measurements taken in the port of Tunis, where the EU rules do not apply, showed that levels of this noxious substance remained the same.”

Measuring the Mediterranean

Air quality measurements were carried out using an automated monitoring station on the cruise ship Costa Pacifica, which followed a fixed weekly route in the Western Mediterranean during 2009 and 2010. The JRC says the results of the monitoring exercise show the decreases in SO2 “are a direct consequence of the application of the EU requirements”.

Sulphur, in particular, is of concern. It is a nasty pollutant, and there has been a great deal of success in cutting emissions from industrial processes and other sources on land.

The JRC says: “In Europe, where SO2 emissions have shown a decreasing trend for 25 years, the emissions from ships are particularly important: in the year 2000, emissions from maritime international shipping in the seas surrounding the EU were between 20% and 30% of the land-based emissions of the EU countries and in 2020, under business-as-usual conditions, emissions from maritime activities are projected to be about as large as those from land-based sources.

“This is, in part, explained by the relatively lenient limits on the sulphur content of marine fuel and engine exhaust limits as well as the projected strong growth in maritime activity.”

The Mediterranean as a region is prone to suffer impacts from shipping pollution. The JRC says: “Ship emissions contribute significantly to air pollution in the Mediterranean Basin. According to the study by Marmer et al (2005), based on an inventory from 1990, 54% of the total sulphate aerosol column burden over the Mediterranean in summer originates from ship emissions.

“For the Mediterranean Sea, a recent report (ENTEC, 2007) estimates for the year 2005 that SO2 emissions from ships at berth in harbours are 95 kilotonnes (kT), compared to their total amount of 883kT.”

Positive impact

According to the JRC’s research, there is no question regulation is having a significant positive impact. Its report, published in Atmospheric Environment, says: “The observations at the measurement station on Costa Pacifica in five Mediterranean harbours in 2009 and 2010 have given strong evidence of a reduction of ambient SO2 concentrations in concomitance with the impact of the EU Directive that regulates the emissions of SO2 from ships in EU harbours from January 2010.

“The concentrations of sulphur dioxide were found to decrease significantly in three out of the four Mediterranean EU harbours that were investigated: Civitavecchia, Savona and Palma de Mallorca; the daily mean concentrations in all of the harbours decreased on average by 66%.

“JRC measurements in the harbour of Barcelona were inconclusive because of large day-to-day concentration variations. However, independent measurements from monitoring stations in the harbour of Barcelona and in the vicinity of the harbour of Palma de Mallorca confirm a strong decrease in sulphur dioxide concentrations from 2009 to 2010.

“In contrast, no decrease in sulphur dioxide was observed in the Mediterranean harbour of Tunis, and there was no reduction in any of the other air pollutants that were measured in all four harbours (Civitavecchia, Savona, Palma de Mallorca and Tunis).

“This shows that the decreases in sulphur dioxide are a direct consequence of the application of the EU requirements. The study also confirms a correlation between sulphur dioxide and chemical elements typically emitted from ship stacks, which demonstrates that ships were the main source of sulphur dioxide in the harbours.”

The shipping industry is the next major target of international and European regulation aimed at cutting air pollution, which will be music to the ears of environmental health officers in all local authorities with ports within their boundaries.

It appears certain permitted emission levels will be cut further over the next decade, reducing the impact of pollutants such as SO2 on both human health and the environment. According to the JRC research, the steps already being taken are proving to have excellent results.

Last reviewed 26 September 2012