Air pollution from ships: Recent developments

All developments on air pollution by ships are fairly recent. Annex VI of the international Marpol-convention, regulating the emissions of CFCs, Halons, Volatile Organic Compounds (VOCs) from cargoes, emissions from incinerators and exhaust gas emissions from engines (NO_x and SO_x) entered into force in May 2005. The International Maritime Organization is currently discussing an upgrade of the air pollution issues covered by Annex VI and some that are not in Annex VI, such as greenhouse gas emissions. CO₂ is the most important greenhouse gas emitted by ship. Fuel consumption by the world merchant fleet is expected to grow to between 250–300 million tons per year with corresponding CO₂ emissions of 800–960 million tons per year. In Western Europe land based measures have reduced sulphur emissions substantially, leaving shipping as an important remaining source of these emissions. Average sulphur content of heavy fuel oils is 3%, with a limit of 4.5% imposed by Annex VI. Both the Baltic- and the North Sea have the status of SO_x emission control area, limiting sulphur content to 1.5%.