The International Maritime Organization (IMO) is updating the greenhouse gas (GHG) emissions estimate for international shipping following a recent meeting with experts and more than a hundred participants from IMO member-states.

The meeting followed the endorsement by IMO’s Marine Environment Protection Committee (MEPC), at its sixty-fourth session in October 2012 of the outline for an update of the GHG emissions estimate.

The current IMO GHG Study 2009 had estimated that international shipping emitted 870 million tonnes, or about 2.7% of the global man-made emissions of carbon dioxide (CO2) in 2007. Exhaust gases are the primary source of GHG emissions from ships, with CO2 the most important GHG, both in terms of quantity and of global warming potential.

As the current estimate contained in the Second IMO GHG Study 2009 does not take account of the economic downturn experienced globally since 2008, an updated GHG emissions estimate should provide MEPC with reliable and up-to-date information to base its decisions on when considering further possible measures to address GHG emissions from international shipping.

IMO said that an updated emissions estimate would also provide a baseline to enable the impact to be assessed of technical and operational energy efficiency measures for international shipping that entered into force on 1 January 2013. The meeting comprised of experts with expertise and experience in the field of estimating fuel consumption and GHG emissions for the international maritime sector, considered the scope of the update study, methodology and assumptions to be used in the update.