Shipping emits a variety of air pollutants: sulphur dioxide (SOx), nitrogen oxides (NOx ), carbon dioxide (CO2 ) and particulate matter PM. Air pollutant emissions from maritime transport can be transported over long distances and thus increasingly contribute to air quality problems. Key environmental regulations (international and European) coming into force in this decade address emissions of SOx , NOx , CO2 and PM to control and limit their impact in the atmosphere. In the European Union, accordingly to the legal regulations, in the sulphur emission control areas the required SOx content of fuel will be reduced from 1.5 % to 0.1 % beginning January 2015. Globally, from 2020 onwards, ships operating in all other European Sea areas will have to use fuels with sulphur content of 0.5 % or less.