Shipping's contribution to climate change - IMO's work on reducing emissions

By Mr Efthimios E. Mitropoulos, Secretary - International Maritime Organization

Huge volumes of cargo are transported by sea globally each year, by safe, efficient and environmentallyfriendly ships. When compared, for example, with road vehicles, shipping is a small contributor to the total volume of atmospheric emissions. To lessen this contribution, a reduction in emissions from ships and an increase in fuel efficiency have been achieved in the past decade through improvements in such factors as engine efficiency and hull design.

In 1997, the International Maritime Organization (IMO), the United Nations specialized agency with responsibility for safety and security of ships and prevention of marine pollution by ships, adopted a set of regulations aimed at preventing air pollution from ships to set the standards for reducing ship emissions in order to contribute to the planned overall reduction needed in atmospheric pollution.

These regulations, contained in an Annex to the International Convention for the Prevention of Pollution from Ships, 1973, as modified by the Protocol of 1978 relating thereto (MARPOL 73/78), entered into force on 19 May 2005 and set limits on sulphur oxide (SOx) and nitrogen oxide (NOx) emissions from ship exhausts as well as prohibiting deliberate emissions of ozone depleting substances. As at 1 November 2005, the Protocol of 1997 to MARPOL 73/78 (Annex VI) has 27 Contracting States, representing 63.52 per cent of world merchant shipping tonnage.

Detailed requirements to cut NOx emissions are contained in the NOx Technical Code and, in fact, engine manufacturers have been complying with the NOx standards since January 2000, in advance of the entry-intoforce date, by producing engines in compliance with the standards adopted in 1997.

The regulations also establish a global cap of 4.5 percent by mass (% m/m) on the sulphur content of fuel oil. The sulphur content of fuel oil used onboard ships operating in a SOx Emission Control Area (SECA) must not exceed 1.5% m/m or, alternatively, ships must fit an exhaust gas cleaning system or use other methods to limit SOx emissions. In fact, information gained from monitoring the worldwide sulphur content in fuel oils for 2004 gives a three-year (2002-2004) rolling average of sulphur content in fuel oil worldwide of 2.67% m/m.

The Baltic Sea was established as a SECA in the 1997 Protocol and IMO's Marine Environment Protection Committee (MEPC) adopted the North Sea as a SECA in July 2005.

Since the adoption of the air pollution regulations, the MEPC has engaged in further discussion on climate change gases, including carbon dioxide (CO2), with the aim of developing technical measures to reduce their emissions. An IMO climate gas study has been completed.

Although Annex VI does not cover the emission of greenhouse gases (GHG) from ships, MEPC has given considerable consideration to the matter, leading to the adoption of Assembly resolution A.963(23) - IMO Policies and Practices related to the Reduction of Greenhouse Gas Emissions from Ships (GHG).

The work of MEPC related to the reduction of GHG emissions from ships is now focused on the development of a GHG Indexing Scheme for ships and Interim Guidelines for Voluntary Ship CO2 Emission Indexing for Use in Trials have been approved. This should enable trials on using the guidelines to be carried out and the results analysed at future MEPC sessions. The guidelines present the concept of an index for the energy efficiency of a ship in operation, limited to an expression of efficiency expressed as CO2 emitted per unit of transport work.

Meanwhile, IMO is to review Annex VI and the NOx Technical Code with a view to revising the regulations to take account of current technology and the need to further reduce emissions from ships. The review, with a target completion date of 2007, will focus on:

	examining available and developing techniques for the reduction of emissions of air pollutants; reviewing relevant technologies and the potential for a reduction of NOx emissions and recommending future limits;
	reviewing technology and the need for a reduction of SOx emissions and justifying and recommending future limits;
	considering the need, justification and possibility of controlling volatile organic compounds emissions from cargoes;
	studying current emission levels of particulate matter (PM) from marine engines, including their size distribution and quantity, and, with a view to controlling emissions of particulate matter (PM), recommending actions to be taken for their reduction. Since reduction of NOx and SOx emission is expected to also reduce PM emissions, estimating levels of PM emission reduction through this route;
	considering reducing NOx and PM emission limits for existing engines;
	considering whether emission reductions or limitations should be extended to include diesel engines that use alternative fuels and engine systems/power plants other than diesel engines; and
	reviewing the texts of Annex VI, NOx Technical Code and related guidelines and recommending necessary amendments. IMO continues to work on reducing harmful emissions from shipping, a transport industry which is vital to world trade and development.

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