The contribution of sulphur dioxide emissions from ships to coastal deposition and air quality in the channel and southern north sea area

Report no. 2/94: The purpose of this report is to present a detailed analysis of the impact of sulphur emissions from ships within the heavily trafficked southern North Sea and Channel as a contribution to the debate on the need to limit the sulphur content of bunker fuels.The fuel consumed by all shipping in the study area was estimated at 4 Mtl year. This compares to a bunker production in Europe of some 25 Mt/year.The study clearly identifies in-port emissions as a significant source of ship emissions in the study area with ships in port contributing some 26% of the total emissions from ships.

As a consequence, the data presented show that in the major ports of Rotterdam, Europoort, Antwerp and Le Havre, ships make a significant contribution to atmospheric concentrations of sulphur dioxide. In addition, they contribute significantly to overall deposition. Throughout the study area, the contribution of ships operating outside territorial waters was less than 5% of total deposition.In areas where ship emissions contribute most significantly to overall deposition and air quality, the study indicates that emission reduction measures in just four of the major ports (of the 80 ports in the study area) would offer a greater benefit to the environment than the control of all at-sea ship emissions within the study area.

Furthermore, the cost of achieving a unit reduction in deposition in such areas through in-port control is some 10-20%of the cost for control of ships operating outside the 12 mile territorial limit.