Photo: / Randy Tarampi CC BY-NC

Great benefits of cutting ship emissions in the Mediterranean Sea

Implementation of a full Emission Control Area could slash air pollutant emissions by between 77 and 95 per cent and avoid more than 6000 premature deaths every year.

A new study shows that taking additional measures to control ship emissions in the Mediterranean Sea would bring significant improvements to air quality, resulting in additional health benefits worth up to €14 billion per year.

Following the adoption of a new national air pollution reduction plan for France in 2017, which envisages the introduction of low-emission zones for shipping in the Mediterranean Sea, the French ministry of environment (MTES) commissioned the French national institute for industrial environment and risks (INERIS) to lead the work on a feasibility study.

The study includes a new inventory of air pollutant emissions from ships in the Mediterranean Sea, valid for the years 2015–2016. Based on this data, emissions for four different scenarios were calculated:

  • REF-MGO: A reference scenario that shows the situation after implementation of the already established IMO global limit of 0.5 per cent sulphur in fuel, which enters into force from 1 January 2020;
  • SECA: A Sulphur Emission Control Area scenario, where the sulphur content in ship fuels is further reduced to 0.1 per cent;
  • SN50: A combined SECA and NOx Emission Control Area (NECA) scenario, which assumes that 50 per cent of the ships fulfil the IMO’s Tier III emission standard for NOx. The Tier III standard reduces NOx emissions by approximately 75 per cent, compared to the currently applicable Tier II standard;
  • SN100: A second combined SECA and NECA scenario, which assumes that 100 per cent of the ships fulfil the IMO’s Tier III emission standard.

It should be noted that the emission estimates for the four scenarios (see Table) were applied to the shipping fleet and activity level of 2015–2016 – no projections about future changes in the shipping fleet or activity levels were done in this study.

Implementing a full Emission Control Area (ECA), which is illustrated by the SN100 scenario, in the Mediterranean Sea results in significant emission cuts – sulphur dioxide (SO2) comes down by 95 per cent, nitrogen oxides (NOx) by 77 per cent and particulate matter (PM2.5) by 80 per cent, compared to the current emission levels.

Advanced computer modelling showed that the additional emission reductions bring clear improvements to air quality, especially in the densely populated coastal areas.

Implementing the already established 2020 global sulphur limit of 0.5 per cent will in itself markedly reduce levels of SO2 and PM2.5, but the study also shows that taking the next step by introducing a full ECA provides significant further improvements. The SN100 scenario results in an additional (on top of the REF-MGO scenario) lowering of ambient levels of harmful SO2 and nitrogen dioxide (NO2) by up to nearly 80 per cent and levels of PM2.5 by up to 11 per cent.

Moreover, the deposition of nitrogen in sensitive ecosystems is reduced by up to 40 per cent, which is of importance to protect biodiversity because of the eutrophication problems caused by the current over-supply of nitrogen to terrestrial and marine ecosystems.

The report provides detailed maps showing the location of the biggest improvements in air quality, and it includes detailed analyses of the air quality in a number of Mediterranean port cities.

By using established concentration-response functions, the study calculated that the REF-MGO scenario would result in about 4500 annually avoided premature deaths due to PM2.5, and that the SN100 scenario would increase this figure to about 6200. On a country-by-country basis, the main beneficiaries are Italy, Algeria, Egypt, Turkey and Greece.

The cost-benefit analysis (see Figure) accounts for the inherent uncertainties in estimating the costs of the emission abatement measures by including both low and high cost estimates. The REF-MGO scenario, which is already a legal commitment, is estimated to cost €1.25–1.83 billion per year. Moving to implement the SECA scenario would cost an additional €0.10–1.25 bn/yr, and going for a full ECA by also introducing NOx emission controls would add €1.27–1.41 bn/yr, i.e. the total costs for the SN100 scenario would be €1.37–2.66 bn/yr.

Similarly as for the cost estimates, the study includes both lower and higher valuations of the health benefits. Implementing the new global sulphur limit (REF-MGO) is calculated to bring health benefits valued at €8.9–14.5 bn/yr, i.e. between 5 and 12 times the cost.

The monetised additional health benefits of moving from REF-MGO to a full ECA (the SN100 scenario) are estimated to amount to €8.1–14 bn/yr, which means that the benefits are between 3 and 10 times higher than the costs.

Commenting on the study, Charlotte Lepitre, at France Nature Environnement (FNE), said: “The study shows the need for a Mediterranean Emission Control Area. The French Environment Ministry must now take its role as a leader and search for support in as many Mediterranean countries as possible.”  

Christer Ågren

The French study “ECAMED: A technical feasibility study for the implementation of an Emission Control Area (ECA) in the Mediterranean Sea”:

NGO factsheet: “Emission Control Area (ECA) for the Mediterranean Sea – Effective measure to tackle air pollution from ships”:

Table: Annual air pollutant emissions from ships in the Mediterranean Sea, under current situation and under four different emission reduction scenarios (thousand tonnes).

      NOx SO2  PM2.5
Current 1,332 759 79
REF-MGO 1,264 153 22
SECA 1,264 35 16
SN50  823 35 16
SN100 303 35 16

Current: Emissions from ships in 2015
REF: Max 0.5% sulphur in fuels
SECA: Max 0.1% sulphur in fuels
SN50: Max 0.1% sulphur in fuels + 50% of ships complying with the Tier III NOx standard
SN100: Max 0.1% sulphur in fuels + 100% of ships complying with the Tier III NOx standard

Figure: Comparison of the estimated annual costs and monetised health benefits of implementing additional emission abatement measures for ships in the Mediterranean Sea (€billion/year).

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