In 1997 a new annex was added to the International Convention for the Prevention of Pollution from Ships (MARPOL). The Regulations for the Prevention of Air Pollution from Ships (Annex VI) seek to minimize airborne emissions from ships (SOx, NOx, ODS, VOC) and their contribution to local and global air pollution and environmental problems. Annex VI entered into force on 19 May 2005 and a revised Annex VI with significant tighten emissions limits was adopted in October 2008 which entered into force on 1 July 2010.
In 2007 international shipping was estimated to have contributed about 2.7% to the global emissions of carbon dioxide (CO2). IMO has adopted mandatory technical and operational energy efficiency measures which will significantly reduce the amount of CO2 emissions from international shipping. The growth of world trade in the future represents a challenge to meeting a target for emissions required to achieve stabilisation in global temperatures and so IMO continues to work on the development of market-based measures as a complimentary means of achieving the required target for emissions.