Future shipping and air quality in the Baltic

Martin Ramacher,
Researcher,
Helmholtz-Zentrum hereon, Coastal Environmental Chemistry,
Geesthacht, Germany

Markus Quante,
Professor,
Helmholtz-Zentrum hereon, Coastal Environmental Chemistry,
Geesthacht, Germany

Matthias Karl,
Researcher,
Helmholtz-Zentrum hereon, Coastal Environmental Chemistry,
Geesthacht, Germany

Volker Matthias,
Researcher,
Helmholtz-Zentrum hereon, Coastal Environmental Chemistry,
Geesthacht, Germany

Jana Moldanova,
Researcher,
IVL Swedish Environmental Research Institute,
Gothenburg, Sweden

Shipping and air quality in the Baltic Sea

In the Baltic Sea region, shipping played a major role in trade for centuries and is expected to grow in the future. However, ships emit a variety of gases and particles into the atmosphere, among them carbon dioxide (CO₂), nitrogen oxides (NO_x), sulphur oxides (SO_x) and soot particles, which are known to negatively impact human health and the environment. It is estimated that shipping contributes a substantial share of air pollution in the Baltic Sea areas. Especially, close to the coastlines in the Southern Baltic Sea, air pollution from shipping can be substantial, leading to health problems and connected costs. In order to prevent and reduce such negative effects, the International Maritime Organization (IMO) applied regulations globally to all ships and more rigid local rules to certain emission control areas, such as parts of the North and Baltic oceans, the US/Canadian coast as well as the Chinese coast. Targeting different pollutants, such areas are called nitrogen emission control area (NECA) or sulphur emission control areas (SECA), respectively.

The BONUS SHEBA project

In the European BONUS project SHEBA (www.sheba-project.eu) lead experts from different fields of environmental, technical and societal sciences were brought together to tackle different negative aspects arising from shipping activities and emissions in the Baltic Sea e.g., air, noise and water pollution and the associated effects on people, the environment and costs. Besides an in-depth analysis of current impacts from shipping, a set of scenarios to describe the emissions from shipping to water, the atmosphere and underwater noise in the years 2012, 2030 and 2040 under assumptions of different policy measures and regulations were defined.

Scenarios for atmospheric emissions from shipping

First, a busines as usual (BAU) scenario was developed, which takes into account technological (size, fuel, etc.) and economic (transport work, development of trade and sectors, etc.) trends in the future development of shipping in the Baltic Sea. The BAU scenario takes into account already decided and/or implemented policy, for example the emission control areas NECA and SECA. Besides the BAU scenario, other scenarios address different aspects under discussion, for example the realization of the Energy Efficiency Design Index (EEDI), which is introduced by the IMO to reduce fuel consumption of newly built ships, but does not take into account any emission control area.

Air quality modelling results

The developed scenarios were applied in air quality modelling systems to identify shipping impacts in the year 2012 and in all future scenarios. The simulations revealed that shipping emissions are the main contributor to atmospheric NO₂ concentrations over the Baltic Sea in the year 2012. In the BAU scenario, the projected NO_x emissions from shipping in the Baltic Sea can are reduced by almost 80% in 2040, which is mainly an effect of the NECA. An even higher reduction of emissions and connected high reduction of air pollution from shipping was simulated for sulphur dioxide due to an already decided strengthening of the regulations of the SECA in 2015. When it comes to particles smaller than 2.5 µm diameter (PM_2.5) the air quality simulations show a decrease by 35% – 37% between 2012 and 2040 in the Baltic Sea region, with reductions by 50% – 60% along the main shipping routes, but smaller reductions over the coastal areas.

Exposure and urban air pollution in Baltic Sea harbor cities

In addition to the identification of the regional impact of shipping, in the SHEBA project the shipping impact on air quality and population for current and future scenarios in different Baltic Sea harbor cities was simulated. Taking into account that about 70% of the ship traffic takes place close to coastlines from where air pollutants  can easily be transported (by wind) towards urban areas and that port cities are major sources of air pollution in general (industries in harbor areas, various machinery in ports, large number of trucks, etc.), it is of major importance to look at the urban population exposure to air pollution from shipping. In an urban-scale air quality and exposure modeling chain it was simulated that in the Baltic Sea harbor cities Rostock (DE), Riga (LV), Gdansk-Gdynia (PL), shipping contributes 5-15% to NO₂ exposure in the year 2012. Simulations with future scenarios for the city of Gothenburg identified reduction potentials of up to 30% for PM_2.5 and up to 60% for NO₂ for the BAU scenario in the year 2040. Moreover, the simulated impact of a wide use of shore-side electricity for ships at berth in 2040 leads to an additional local reduction potential of up to 3% for PM_2.5 and up to 30% for NO₂ in the proximity of the port area.

Acknowledgement: We gratefully acknowledge the extremely valuable contributions of our colleagues Erik Fridell (IVL), Lasse Johansson (FMI) and Jukka-Pekka Jalkanen (FMI) to the air quality research within BONUS SHEBA.

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