Air Emissions

Ships generate emissions of sulfur oxides  (SOx), oxides of nitrogen (NOx), particulate matter (PM) and carbon dioxide (CO2)  as a result of the fuel used to power them. Ship generated emissions can be significant in areas subject to heavy marine traffic so many actions have been undertaken in recent years to significantly reduce air emissions from ships. Most of these actions have been taken through Annex VI of MARPOL, an international treaty developed through the International Maritime Organization (IMO) that establishes legally-binding international standards to regulate specific emissions and discharges generated by ships.

The World Shipping Council and its members have been leaders in calling for the establishment of stringent international standards controlling air emissions from ships. In 2007, the WSC supported the most stringent standards ever proposed for nitrogen oxides (NOx), sulfur oxides (SOx), and particulate matter (PM) emissions from ships. These standards are now in force and are projected to result in significant air quality improvements. More recently, the WSC, together with other organizations and governments, is engaged in discussions at the IMO and with the European Commission that seek to reduce carbon emissions generated by the shipping sector.

NOx, SOx & PM

Oxides of nitrogen (NOx), sulfur oxides (SOx), and particulate matter (PM) are by-products of combustion associated with engines used on ships and other transportation modes. NOx emissions from diesel engines are a function of engine design and are generally controlled through standards established for new engines. SOx and PM emissions are heavily influenced by the fuel used and its relative sulfur content. Standards for these and other air emissions are established by the International Maritime Organization as well as national and regional authorities. Learn more

Carbon Emissions

Maritime traffic accounts for approximately 2.1% of the world’s CO2 emissions and liner shipping accounts for approximately ¼ of the total 2.1% associated with all maritime traffic, while moving roughly 52% of maritime commerce by value. Like other air emissions discussed above, CO2 is produced as ships use petroleum based fuels to power both main and auxiliary engines. The World Shipping Council and its members are engaged in numerous efforts to reduce CO2, improve efficiency, and are working to secure a global agreement addressing CO2 emissions from ships through the International Maritime Organization. Learn more