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Low carbon shipping and air pollution control


Emissions from ships exhausts into the atmosphere can potentially be harmful to human health and cause acid rain and may also contribute to global warming.

To ensure that shipping is cleaner and greener, IMO is engaging in a two-pronged approach towards addressing GHG emissions from international shipping: through regulatory work, supported by capacity-building initiatives.

Firstly, IMO has adopted regulations to address the emission of air pollutants from ships and has adopted mandatory energy-efficiency measures to reduce emissions of greenhouse gases from international shipping, under Annex VI of IMO’s pollution prevention treaty (MARPOL).

And secondly, IMO is engaging in global capacity-building projects to support the implementation of those regulations and encourage innovation and technology transfer.

In April 2018, IMO adopted an  Initial IMO Strategy on reduction of GHG emissions from ships.

 Initial IMO Strategy on reduction of GHG emissions from ships

In April 2018, IMO's Marine Environment Protection Committee (MEPC) adopted an initial strategy on the reduction of greenhouse gas emissions from ships, setting out a vision to reduce GHG emissions from international shipping and phase them out, as soon as possible in this century. The vision confirms IMO’s commitment to reducing GHG emissions from international shipping and, as a matter of urgency, to phasing them out as soon as possible.

More specifically, under the identified “levels of ambition”, the initial strategy envisages for the first time a reduction in total GHG emissions from international shipping which, it says, should peak as soon as possible and to reduce the total annual GHG emissions by at least 50% by 2050 compared to 2008, while, at the same time, pursuing efforts towards phasing them out entirely.

The strategy includes a specific reference to “a pathway of CO2 emissions reduction consistent with the Paris Agreement temperature goals”.

The full text of the Initial IMO Strategy on reduction of GHG emissions from ships can be downloaded here, in IMO's submission to the Talanoa Dialogue. The Talanoa Dialogue portal has been established by the UN Climate Change secretariat for countries and stakeholders to contribute information that can assist the world in taking climate action to the next level in order to meet the objectives of the Paris Agreement and support the Sustainable Development Goals (SDGs).

 Shipping and Climate Change videos

​These three short videos explain IMO's energy-efficiency requirements and highlight capacity-building as a way to promote uptake of the measures.

 Combatting air pollution from shipping

​IMO regulations to address air pollutants from international shipping, particularly sulphur oxide (SOx) and nitrogen oxide (NOx), have been successful in lowering the amount of those pollutants being emitted from ships.  Further strengthening of the requirements are set to continue. 

There are global caps, with more stringent requirements in Emission Control Areas or ECAS.  Currently, there are four ECAS designated by IMO:

  1. Baltic Sea area (SOx only);

  2. North Sea area (SOx only);

  3. North American area (SOx, NOx and PM); and

  4. United States Caribbean Sea area  (SOx, NOx and PM).

In SECAS, the sulphur cap is 0.10% m/m (mass/mass).

Outside SECAS, the global sulphur cap will be cut to 0.50% from 1 January 2020 (from 3.5% m/m currently).

Limiting SOemissions from ships will improve air quality and protects the environment. Read more here

MARPOL Annex VI regulations to restrict air pollution from ships were first adopted in 1997. ​​​​​​A revised  Annex VI was adopted in 2005 and it entered into force in 2010, phasing in a progressive reduction in sulphur oxide (SOx) from ships and further reductions in nitrogen oxide (NOx) emissions from marine engines.

Further information about prevention of air pollution from ships here.

 Energy-efficiency requirements

​IMO is the only organization to have adopted energy-efficiency measures that are legally binding across an entire global industry, applying to all countries.

IMO has established a series of baselines for the amount of fuel each type of ship burns for a certain cargo capacity. Ships built in the future will have to beat that baseline by a set amount, which will get progressively tougher over time. By 2025, all new ships will be a massive 30% more energy efficient than those built in 2014.

Under the energy-efficiency regulations, existing ships now have to have an energy efficiency management plan in place, looking at things like improved voyage planning, cleaning the underwater parts of the ship and the propeller more often, introducing technical measures such as waste heat recovery systems, or even fitting a new propeller.

The energy-efficiency requirements were adopted as amendments to MARPOL Annex VI  in 2011 and they entered into force on 1 January 2013​​. The regulations make mandatory the Energy Efficiency Design Index (EEDI)  mandatory for new ships, and the Ship Energy Efficiency Management Plan (SEEMP) is made a requirement for all ships.

In 2016, IMO adopted mandatory requirements for ships of 5,000 gross tonnage and above will have to collect consumption data for each type of fuel oil they use, as well as other, additional, specified data including proxies for transport work. These ships account for approximately 85% of CO2 emissions from international shipping. The data collected will provide a firm basis on which future decisions on additional measures, over and above those already adopted by IMO, can be made.

The Marine Environment Protection Committee (MEPC) has also approved a roadmap (2017 through to 2023) for developing a “Comprehensive IMO strategy on reduction of GHG emissions from ships”. An initial GHG strategy was adopted in 2018.

Read more on energy efficiency requirements here.

IMO continues to work on refining guidance and on the implementation of the regulations, through the MEPC.

 Global Maritime Energy Efficiency Partnership (GloMEEP) Project


The GEF-UNDP-IMO Global Maritime Energy Efficiency Partnership (GloMEEP) Project, which aims to build understanding and knowledge of technical and operational energy-efficiency measures to lead maritime transport into a low-carbon future. The two-year project involves 10 lead pilot countries (Argentina, China, Georgia, India, Jamaica, Malaysia, Morocco, Panama, Philippines and South Africa) and aims to create global, regional and national partnerships to build the capacity to address maritime energy efficiency and for countries to bring this issue into the mainstream within their own development policies, programmes and dialogues. The first national workshop under the Project was held in December 2015.

As well as developing training materials and delivering workshops, the GloMEEP project has developed an information portal which provides users with information on the wide spectrum of technologies to reduce ship fuel consumption, including new and novel technologies.


 Global MTTC Network (GMN) Project

Funded by the European Union and implemented by the International Maritime Organization, the Global MTTC Network (GMN) – formally titled “Capacity Building for Climate Mitigation in the Maritime Shipping Industry ” – initiative unites technology centres – Maritime Technologies Cooperation Centres (MTCCs) – in targeted regions into a global network. Together, they are promoting technologies and operations to improve energy efficiency in the maritime sector and help navigate shipping into a low-carbon future.

Watch the IMO video:


Developing countries and, in particular, Least Developed Countries and Small Islands Developing States, will be the main beneficiaries of this ambitious initiative

The aim of the Global MTTC Network (GMN) project is to help beneficiary countries limit and reduce GHG emissions from their shipping sectors through technical assistance and capacity building. It will encourage the uptake of innovative energy-efficiency technologies among a large number of users through the widespread dissemination of technical information and know-how. This will heighten the impact of technology transfer.

The four-year project will target five regions – Africa, Asia, the Caribbean, Latin America and the Pacific. These have been targeted for their significant number of Least Developed Countries (LDCs) and Small Island Developing States (SIDS).

Carefully selected to become centres of excellence for their regions, the MTCCs will focus on technical co-operation, capacity building and technology transfer. Supported by IMO and EU, the MTCCs act as regional focal points for a wide range of activities to:

  • improve compliance with existing and future international energy-efficiency regulations
  • help participating countries develop national energy-efficiency policies and measures for their maritime sectors
  • promote uptake of low-carbon technologies and operations in maritime transport
  • establish voluntary pilot data-collection and reporting systems to feed back into the global regulatory process.

The five host institutions are:

MTCC-Africa: Jomo Kenyatta University of Agriculture and Technology (JKUAT), Kenya

MTCC-Asia: Shanghai Maritime University, China

MTCC-Caribbean: University of Trinidad and Tobago

MTCC-Latin America: International Maritime University of Panama (UMIP)

MTCC-Pacific:  Pacific Community (SPC) in collaboration with the Secretariat of the Pacific Regional Environment Programme (SPREP)

Participants and stakeholders can keep up to date with the project's progress via the GMN 6-month summary report. Click here for issue 1, 2017


 Studies and reports

​(The views and conclusions expressed in the studies are those of the authors)
  • Third IMO GHG Study (2014)

  • Investigation of appropriate control measures (abatement technologies) to reduce Black Carbon emissions from
    international shipping (2015)

  • Study of Emission Control and Energy Efficiency Measures for Ships in the Port Area (2015)

  • Studies on the feasibility and use of LNG as a fuel for shipping (2016)

See also publications and resources on the following websites:


​IMO participates in the UN Climate Change Conferences, providing updates to the Subsidiary Body for Scientific and Technological Advice (SBSTA) under agenda item 10 on Emissions from fuel used for international aviation and maritime transport

Download the IMO submission to the Talanoa Dialogue here. This includes the full text of the Initial IMO Strategy on reduction of GHG emissions from ships.

Although shipping was not included in the final text of the Paris Agreement, adopted in 2015, IMO has set itself a long-standing mandate to contribute to the fight against climate change by addressing greenhouse gas emissions from ships.