In coastal areas and port cities, ship exhaust gases pollute the air. Ships emit mainly trace gases such as nitrogen oxides (NOx), carbon dioxide (CO2), sulphur dioxide (SO2), but also soot and particulate matter. This has an impact on health, the environment and the climate.
At the international level, under the umbrella of the International Maritime Organization (IMO), regulations have been agreed to protect the marine environment from pollution by shipping (MARPOL). Since 2005, Annex VI of the MARPOL Convention regulates the protection against air pollution caused by ship emissions. In 2006 and 2005, the North Sea and Baltic Sea were designated as special sulphur emission control areas (SECA). Since 1 January 2015, only marine fuels with a maximum sulphur content of 0.10 % S m/m may be used within these areas. Outside the emission control areas, ship operation with heavy fuel oil, which was not allowed to exceed a sulphur content of 3.50 % S m/m, was permitted until the end of 2019. On 01.01.2020 this limit was lowered to 0.50 % S m/m. Alternatively, the use of exhaust gas cleaning systems (scrubber) is permitted if sulphur emissions are reduced in the same way as through the use of low-sulphur fuels. Both alternatives are associated with increased operational costs for shipping compared to the use of high sulphur heavy fuel oil. Depending on the extent of air pollution, infringements will be prosecuted as an misdemeanour by the BSH or as a criminal offence by the public prosecutor's office.
Measurements of the chemical composition of ship exhaust plumes and the analysis of marine fuel samples show that, fortunately, the majority of ships comply with existing regulations. This development has led to a significant reduction in sulphur dioxide pollution in coastal areas and along shipping lanes. Since 2015, a reduction of atmospheric sulphur dioxide pollution in the coastal areas by more than 50% has been observed (Source: Kattner et al., 2015; Seyler et al., 2017). From 2021, more stringent rules on nitrogen oxide emissions will also apply in the North Sea and Baltic Sea (TIER-3).
In order to efficiently monitor compliance with existing and future regulations for sulphur and nitrogen oxide emissions, the BSH is setting up an air monitoring network in the German coastal region. The BSH is cooperating with European partners and research institutions to implement European monitoring with comparable quality standards.