Sulphur dioxide SO2
Sources
Sulphur dioxide has anthropogenic sources as combustion processes of fossil fuels and natural sources as volcanic eruption. Through chemical reactions of the precursors the atmospheric secondary aerosol SO4 is formed (gas to particle conversion).
Health effects
High air pollution of the secondary particles is responsible for a great number of diseases as stroke, heart disease, lung cancer, and both chronic and acute respiratory diseases, including asthma.
Environmental impact
SO2 is a precursor to sulfate (SO4), which is associated with acidification of waterbodies and acid rain, accelerated corrosion of buildings and monuments and reduced visibility.
SO2 concentrations
The total concentrations of SO2 are neither in the summer nor in the winter months very high, expect from very few hot spots.
Relative contribution of ships to SO2 concentrations
The relative contribution of ships is higher in the summer months, which is mainly due to overall lower SO2 concentrations within the warmer season. The contribution of ships to the concentrations over the English Channel and over the main shipping routes are up to 100 % during summer.
Scenario No ECA: SO2 Concentration Change
In the scenarios for 2030 all ships follow the same rules for sulphur, which allow only 0.1% S in fuels within the ECA and 0.5% outside the borders of the ECA. Therefore, the scenarios do not differ much in terms of sulfur concentrations.
Scenario ECA SCR 21: SO2 Concentration Change
In the scenarios for 2030 all ships follow the same rules for sulphur, which allow only 0.1% S in fuels within the ECA and 0.5% outside the borders of the ECA. Therefore, the scenarios do not differ much in terms of sulfur concentrations.
Scenario ECA SCR/LNG 16: SO2 Concentration Change
In the scenarios for 2030 all ships follow the same rules for sulphur, which allow only 0.1% S in fuels within the ECA and 0.5% outside the borders of the ECA. Therefore, the scenarios do not differ much in terms of sulfur concentrations.
LNG does not contain any sulphur, which is why a difference can be seen between the ECA LNG and the ECA SCR (0.1% sulphur). The ECA LNG 16 scenario shows that SO2 is even further reduced (60- 80%) compared to the reduction of the concentration in the ECA SCR 16 scenario (40-60%).
Scenario ECA opt: SO2 Concentration Change
In the scenarios for 2030 all ships follow the same rules for sulphur, which allow only 0.1% S in fuels within the ECA and 0.5% outside the borders of the ECA. Therefore, the scenarios do not differ much in terms of sulfur concentrations.