Traditionally, the environmental performance of ships in terms of air emissions has never been among the primary concerns of the maritime industry. However, this situation is bound to change considering that the greening of the transportation sector is imminent and unavoidable. This tendency is manifested with activities ranging from regularly published statistics regarding the air pollution of general industrial activity up to the Energy Efficiency Design and Operation Index that are currently being considered at IMO.

The greening of shipping operations has to do with more than just the amount of NOx, SOx and CO2 gases emitted at any period of time: the fact that for every tonne of fuel burnt approximately three tonnes of CO2 are produced indicates that the environmental performance of ships is linked to their cost-effectiveness. As a result, consistent energy management onboard will become a priority for rule compliance, and robustness against unpredictable financial fluctuations.