Reducing greenhouse gas emissions from ships
IMO continues to contribute to the global fight against climate change, in support of the UN Sustainable Development Goal 13, to take urgent action to combat climate change and its impacts.
IMO has adopted mandatory measures to reduce emissions of greenhouse gases from international shipping, under IMO’s pollution prevention treaty (MARPOL) - the Energy Efficiency Design Index (EEDI) mandatory for new ships, and the Ship Energy Efficiency Management Plan (SEEMP)..
In 2018, IMO adopted an initial IMO strategy on reduction of GHG emissions from ships, setting out a vision which confirms IMO’s commitment to reducing GHG emissions from international shipping and to phasing them out as soon as possible.
IMO is also executing global technical cooperation projects to support the capacity of States, particularly developing States to implement and support energy efficiency in the shipping sector.
Click on the image on the right to view and download a PDF leaflet on IMO Action to reduce greenhouse gas emissions from international shipping, including a timeline.
Below you will find some frequently asked questions about IMO's work to reduce GHG emissions from shipping.
A detailed historical overview of IMO's work can be found here.
What are the next steps in implementing the GHG strategy?
In October 2018 (MEPC 73), IMO approved a follow-up programme, intended to be used as a planning tool in meeting the timelines identified in the initial IMO strategy. The streams of activity identified in the programme of follow-up actions include:
- candidate short-term measures (Group A) that can be considered and addressed under existing IMO instruments;
- candidate short-term measures (Group B) that are not work in progress and are subject to data analysis;
- candidate short-term measures (Group C) that are not work in progress and are not subject to data analysis;
- candidate mid-/long-term measures and action to address the identified barriers;
- impacts on States;
- Fourth IMO GHG Study;
- capacity-building, technical cooperation, research and development; and
- follow-up actions towards the development of the revised Strategy – set to be adopted in 2023.
Member States have been invited to submit concrete proposals on candidate short-term and mid-term measures to the Marine Environment Protection Committee (MEPC). The MEPC is the decision-making body. The MEPC usually establishes a Working Group on Reduction of GHG Emissions from Ships, which meets during each MEPC session and reports to the plenary of the Committee.
To help move forward with the implementation of the initial GHG strategy, intersessional meetings of the working group are also held.
The sixth meeting of the Intersessional Working Group on Reduction of GHG Emissions from Ships met 11-15 November 2019. (Read outcome here.)
The seventh meeting of the Intersessional Working Group on Reduction of GHG Emissions from Ships is scheduled to be held ahead next Committee session, MEPC 75.
The intersessional working group will:
- further consider concrete proposals to improve the operational energy efficiency of existing ships, with a view to developing draft amendments to Chapter 4 of MARPOL Annex VI and associated guidelines, as appropriate;
- further consider concrete proposals to reduce methane slip and emissions of Volatile Organic Compounds (VOCs);
- consider a draft MEPC resolution urging Member States to develop and update a voluntary National Action Plan (NAP) with a view to contributing to reducing GHG emissions from international shipping, and develop associated guidelines, as appropriate;
- further consider concrete proposals to encourage the uptake of alternative low-carbon and zero-carbon fuels, including the development of lifecycle GHG/carbon intensity guidelines for all relevant types of fuels and incentive schemes, as appropriate;
- consider the development of further actions on capacity-building, technical cooperation, research and development, including support for assessment of impacts and support for implementation of measures; and
- consider other concrete proposals for candidate measures.
The Intersessional Working Group on Reduction of GHG Emissions from Ships reports to the MEPC. So any recommendations can be put forward to the Committee. Member States can submit their proposals to the working group for discussion. The working group is also open to NGOs in consultative status with IMO as well as intergovernmental organizations.
What does the initial IMO GHG strategy say?
The initial GHG strategy envisages, in particular, a reduction in carbon intensity of international shipping (to reduce CO2 emissions per transport work, as an average across international shipping, by at least 40% by 2030, pursuing efforts towards 70% by 2050, compared to 2008); and that total annual GHG emissions from international shipping should be reduced by at least 50% by 2050 compared to 2008.
The strategy includes a specific reference to “a pathway of CO2 emissions reduction consistent with the Paris Agreement temperature goals”.
The initial strategy represents a framework for Member States, setting out the future vision for international shipping, the levels of ambition to reduce GHG emissions and guiding principles; and includes candidate short-, mid- and long-term further measures with possible timelines and their impacts on States. The strategy also identifies barriers and supportive measures including capacity building, technical cooperation and research and development (R&D).
The strategy envisages that a revised strategy will be adopted in 2023. Feeding in to the process towards the adoption of the revised Strategy in 2023 will be the data collection system on fuel oil consumption of ships over 5,000 gross tons, which began on 1 January 2019.
What is the vision and what are the levels of ambition in the strategy?
The initial strategy includes the following:
IMO remains committed to reducing GHG emissions from international shipping and, as a matter of urgency, aims to phase them out as soon as possible in this century.
Levels of ambition
The Initial Strategy identifies levels of ambition for the international shipping sector noting that technological innovation and the global introduction of alternative fuels and/or energy sources for international shipping will be integral to achieve the overall ambition. Reviews should take into account updated emission estimates, emissions reduction options for international shipping, and the reports of the Intergovernmental Panel on Climate Change (IPCC ). Levels of ambition directing the Initial Strategy are as follows:
.1 carbon intensity of the ship to decline through implementation of further phases of the energy efficiency design index (EEDI) for new ships
to review with the aim to strengthen the energy efficiency design requirements for ships with the percentage improvement for each phase to be determined for each ship type, as appropriate;
.2 carbon intensity of international shipping to decline
to reduce CO2 emissions per transport work, as an average across international shipping, by at least 40% by 2030, pursuing efforts towards 70% by 2050, compared to 2008; and
.3 GHG emissions from international shipping to peak and decline
to peak GHG emissions from international shipping as soon as possible and to reduce the total annual GHG emissions by at least 50% by 2050 compared to 2008 whilst pursuing efforts towards phasing them out as called for in the Vision as a point on a pathway of CO2 emissions reduction consistent with the Paris Agreement temperature goals.
Note: The Paris Agreement on climate change was agreed in 2015 by Parties to the United Nations Framework Convention on Climate Change (UNFCCC) and entered into force in 2016. The Paris Agreement central aim is to strengthen the global response to the threat of climate change by keeping a global temperature rise this century well below 2 degrees Celsius above pre-industrial levels and to pursue efforts to limit the temperature increase even further to 1.5 degrees Celsius. The Paris Agreement does not include international shipping, but IMO, as the regulatory body for the industry, is committed to reducing greenhouse gas emissions from international shipping.
Which energy efficiency requirements has IMO already adopted?
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. The "phase 3" requirements have already been reviewed and will be strengthened - this comes under the candidate measures in the IMO initial strategy on reduction of GHG emissions from ships.
The MEPC 74th session in May 2019 approved, for adoption at the next session, amendments to MARPOL Annex VI to significantly strengthen the Energy Efficiency Design Index (EEDI) "phase 3" requirements.
The draft amendments bring forward the entry into effect date of phase 3 to 2022, from 2025, for several ship types, including gas carriers, general cargo ships and LNG carriers. This means that new ships built from that date must be significantly more energy efficient than the baseline.
- For container ships, the EEDI reduction rate is enhanced, significantly for larger ship sizes, as follows:
- For a containership of 200,000 DWT and above, the EEDI reduction rate is set at 50% from 2022
- For a containership of 120,000 DWT and above but less than 200,000 DWT, 45% from 2022
- For a containership of 80,000 DWT and above but less than 120,000 DWT, 40% from 2022
- For a containership of 40,000 DWT and above but less than 80,000 DWT, 35% from 2022
- For a containership of 15,000 DWT and above but less than 40,000 DWT, 30% from 2022
The MEPC also agreed terms of reference for a correspondence group to look into the introduction of a possible "phase 4" of EEDI requirements.
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.
Read more on energy efficiency requirements here.
IMO continues to work on refining guidance and on the implementation of the regulations, through the MEPC.
Procedure for assessing impacts on States of candidate measures
The initial strategy recognizes that the impacts on States of a measure should be assessed and taken into account as appropriate before adoption of the measure. Particular attention should be paid to the needs of developing countries, especially small island developing States (SIDS) and least developed countries (LDCs). When assessing impacts on States the impact of a measure should be considered, as appropriate, inter alia, in the following terms:
- geographic remoteness of and connectivity to main markets;
- cargo value and type;
- transport dependency;
- transport costs;
- food security;
- disaster response;
- cost-effectiveness; and
- socio-economic progress and development.
Disproportionately negative impacts should be assessed and addressed, as appropriate.
MEPC 74 (May 2019) approved the Procedure for assessing impacts on States of candidate measures for reduction of GHG emissions from ships. The procedure identifies four steps:
- Step 1: initial impact assessment, to be submitted as part of the initial proposal to the Committee for candidate measures;
- Step 2: submission of commenting document(s), if any;
- Step 3: comprehensive response, if requested by commenting document(s); and
- Step 4: comprehensive impact assessment, if required by the MEPC.
Impact assessments should be evidence-based and should take into account, as appropriate, analysis tools and models, such as, cost-effectiveness analysis tools, e.g. maritime transport cost models, trade flows models, impact on Gross Domestic Product (GDP); updated Marginal Abatement Cost Curves (MACCs); and economic trade models, transport models and combined trade-transport models.
Cooperation with ports to reduce emissions from shipping
MEPC 74 (May 2019) adopted resolution MEPC.323(74) on Invitation to Member States to encourage voluntary cooperation between the port and shipping sectors to contribute to reducing GHG emissions from ships.
This could include regulatory, technical, operational and economic actions, such as the provision of: Onshore Power Supply (preferably from renewable sources); safe and efficient bunkering of alternative low-carbon and zero-carbon fuels; incentives promoting sustainable low-carbon and zero-carbon shipping; and support for the optimization of port calls including facilitation of just-in-time arrival of ships.
The Global Industry Alliance to support low carbon shipping (GIA), operating under the auspices of IMO’s GloMEEP project, has recognized the key role of ports in the decarbonization of shipping. In particular, just-in-time (JIT) operation of ships has a potential to reduce emissions. The GIA has been gathering experience from ports that have successfully (or unsuccessfully) implemented JIT; has been analysing barriers; and has been studying concrete measures for removal of these barriers to large-scale uptake of JIT. Read more here and watch the Just-in-Time video animation.
What about speed as a measure?
The initial GHG strategy adopted by IMO includes a range of candidate short-term measures – including: “consider and analyse the use of speed optimization and speed reduction as a measure, taking into account safety issues, distance travelled, distortion of the market or to trade and that such measure does not impact on shipping's capability to serve remote geographic areas”.
So this is certainly something that Member States are discussing.
The guidelines for the mandatory Ship Energy Efficiency Management Plan (SEEMP) already refer to "speed optimization" as a potential approach to improve the energy efficiency of the ship, recognizing that speed optimization can produce significant savings.
The 2016 Guidelines for the development of a ship energy efficiency management plan (SEEMP) can be downloaded here.
What about biofuels?
Biofuels could be one of the options. If we are to achieve the goals set out in the initial strategy it will be important to develop and implement measures suitable for the existing fleet.
The advantage of such biofuels is their ‘drop-in’ capability to be used in the existing fleet meaning that they can readily replace hydrocarbon liquid fuels. However, it is an imperative that such biofuels are produced from sustainable feedstocks and using sustainable energy supplies. There are also wider considerations, such as availability, and sustainability of the production of biofuel and so on.
Which new fuels will be needed?
It is clear that the global introduction of alternative fuels and/or energy sources for international shipping will be integral to achieve the overall ambitions set out in IMO’s initial strategy for reducing GHG emissions from international shipping.
There is room for all options to be considered, including electric and hybrid power, hydrogen and other fuel types.
There is also a lot that can be done to improve energy efficiency of ships through operational measures. The IMO-industry alliance (GIA) is looking at how the barriers to just-in-time ship operation can be mitigated. Currently, many ships expend hours or days waiting outside ports and running their diesel engines – just-in-time operations could significantly cut emissions.
Is zero-carbon shipping going to become a reality?
In the initial IMO strategy, there is a clear ambition to pursue efforts towards phasing out GHG emissions from international shipping entirely, by the end of this century. This has to become a reality.
As United Nations Secretary-General Antonio Guterres has said, “We need to put the brake on deadly greenhouse gas emissions and drive climate action…. The world is counting on all of us to rise to the challenge before it’s too late”
Research and development will be crucial, as the targets agreed in the IMO initial strategy will not be met using fossil fuels. There is a need to make zero-carbon ships more attractive and to direct investments towards innovative sustainable technologies and alternative fuels.
What needs to happen over the next two or three decades?
Some of the things that have been identified in the GHG strategy include looking at the provision of ship and shore-side/on-shore power supply from renewable sources and developing infrastructure to support supply of alternative low-carbon and zero-carbon fuels.
The need to further optimize the logistic chain and its planning, including ports is also identified as a candidate short-term measure, along with the initiation of research and development activities addressing marine propulsion, alternative low-carbon and zero-carbon fuels, and innovative technologies to further enhance the energy efficiency of ships.
In the mid-term, the strategy identifies candidate measures, including an implementation programme for the effective uptake of alternative low-carbon and zero-carbon fuels, including update of national actions plans to specifically consider such fuels. In this regard, there may need to be further consideration given as to how to incentivise the uptake of alternative fuels and innovative technologies.
Also identified as a candidate short-term measure is the need to undertake additional GHG emission studies and consider other studies to inform policy decisions, including the updating of Marginal Abatement Cost Curves and alternative low-carbon and zero-carbon fuels.
Which global projects support the GHG strategy?
Support for implementation of IMO’s energy-efficiency measures is provided, in particular, through major global projects executed by IMO. These include:
The Global Maritime Energy Efficiency Partnerships Project (GloMEEP Project), aimed at supporting the uptake and implementation of energy efficiency measures for shipping, thereby reducing greenhouse gas emissions from shipping. The GloMEEP project was launched in 2015 in collaboration with the Global Environment Facility and the United Nations Development Programme. Website: http://glomeep.imo.org/
The "Global Industry Alliance to Support Low Carbon Shipping" (or GIA), launched in 2017 under the auspices of the GloMEEP Project, is identifying and developing solutions that can support overcoming barriers to the uptake of energy efficiency technologies and operational measures in the shipping sector. Website: https://glomeep.imo.org/global-industry-alliance/global-industry-alliance-gia/
The global maritime technology network (GMN) project, funded by the European Union, has established a network of five Maritime Technology Cooperation Centres (MTCCs) in Africa, Asia, the Caribbean, Latin America and the Pacific. Through collaboration and outreach activities at regional level, the MTCCs will focus their efforts during 2018 and beyond to help countries develop national maritime energy-efficiency policies and measures, promote the uptake of low-carbon technologies and operations in maritime transport and establish voluntary pilot data-collection and reporting systems. Website: http://gmn.imo.org/
GreenVoyage-2050 project, a collaboration between IMO and the Government of Norway. The project, launched in 2019, will initiate and promote global efforts to demonstrate and test technical solutions for reducing such emissions, as well as enhancing knowledge and information sharing to support the IMO GHG reduction strategy. Read more here.
Multi-donor trust fund for GHG - MEPC 74 (May 2019) agreed to establish a voluntary multi-donor trust fund ("GHG TC-Trust Fund"), to provide a dedicated source of financial support for technical cooperation and capacity-building activities to support the implementation of the Initial IMO Strategy on reduction of GHG emissions from ships.
Where can I download the strategy?
The full text of the Initial IMO Strategy on reduction of GHG emissions from ships can be found in the submission to the Talanoa Dialogue here.
The initial strategy includes candidate measures (see details further down this page), with the following timelines:
- possible short-term measures could be measures finalized and agreed by the Committee between 2018 and 2023. Dates of entry into force and when the measure can effectively start to reduce GHG emissions would be defined for each measure individually;
- possible mid-term measures could be measures finalized and agreed by the Committee between 2023 and 2030. Dates of entry into force and when the measure can effectively start to reduce GHG emissions would be defined for each measure individually; and
- possible long-term measures could be measures finalized and agreed by the Committee beyond 2030. Dates of entry into force and when the measure can effectively start to reduce GHG emissions would be defined for each measure individually.
Does IMO participate in the UN COP climate change conferences?
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. Read more here on the UNFCCC website here.
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.
IMO at the UN Climate Summit
IMO was in attendance at the UN High Level Week of Action
for People and Planet. This included the Climate Action Summit; (23 September 2019). The UN Secretary-General has convened the Climate Action Summit to increase ambition and accelerate action by countries and other stakeholders, including the private sector.
Which candidate short-term measures are included in the initital strategy?
Candidate short-term measures are measures which can be categorized as those the effect of which is to directly reduce GHG emissions from ships and those which support action to reduce GHG emissions from ships.
All the following candidate measures represent possible short-term further action of IMO on matters related to the reduction of GHG emissions from ships:
- further improvement of the existing energy efficiency framework with a focus on EEDI and SEEMP, taking into account the outcome of the review of EEDI regulations;
- develop technical and operational energy efficiency measures for both new and existing ships, including consideration of indicators in line with the three-step approach that can be utilized to indicate and enhance the energy efficiency performance of shipping, e.g. Annual Efficiency Ratio (AER), Energy Efficiency per Service Hour (EESH), Individual Ship Performance Indicator (ISPI), Fuel Oil Reduction Strategy (FORS);
- establishment of an Existing Fleet Improvement Programme;
- consider and analyse the use of speed optimization and speed reduction as a measure, taking into account safety issues, distance travelled, distortion of the market or to trade and that such measure does not impact on shipping's capability to serve remote geographic areas;
- consider and analyse measures to address emissions of methane and further enhance measures to address emissions of Volatile Organic Compounds;
- encourage the development and update of national action plans to develop policies and strategies to address GHG emissions from international shipping in accordance with guidelines to be developed by the Organization, taking into account the need to avoid regional or unilateral measures;
- continue and enhance technical cooperation and capacity-building activities under the ITCP;
- consider and analyse measures to encourage port developments and activities globally to facilitate reduction of GHG emissions from shipping, including provision of ship and shore-side/on-shore power supply from renewable sources, infrastructure to support supply of alternative low carbon and zero-carbon fuels, and to further optimize the logistic chain and its planning, including ports;
- initiate research and development activities addressing marine propulsion, alternative low-carbon and zero-carbon fuels, and innovative technologies to further enhance the energy efficiency of ships and establish an International Maritime Research Board to coordinate and oversee these R&D efforts;
- incentives for first movers to develop and take up new technologies;
- develop robust lifecycle GHG/carbon intensity guidelines for all types of fuels, in order to prepare for an implementation programme for effective uptake of alternative low-carbon and zero-carbon fuels;
- actively promote the work of the Organization to the international community, in particular, to highlight that the Organization, since the 1990's,has developed and adopted technical and operational measures that have consistently provided a reduction of air emissions from ships, and that measures could support the Sustainable Development Goals, including SDG 13 on Climate Change; and
- undertake additional GHG emission studies and consider other studies to inform policy decisions, including the updating of Marginal Abatement Cost Curves and alternative low-carbon and zero-carbon fuels.
Which candidate mid-term measures are included in the initial strategy?
Candidate mid-term measures are measures which can be categorized as those the effect of which is to directly reduce GHG emissions from ships and those which support action to reduce GHG emissions from ships. All the following candidate measures represent possible mid-term further action of IMO on matters related to the reduction of GHG emissions from ships:
- implementation programme for the effective uptake of alternative low carbon and zero-carbon fuels, including update of national actions plans to specifically consider such fuels;
- operational energy efficiency measures for both new and existing ships including indicators in line with three-step approach that can be utilized to indicate and enhance the energy efficiency performance of ships;
- new/innovative emission reduction mechanism(s), possibly including Market-based Measures (MBMs), to incentivize GHG emission reduction;
- further continue and enhance technical cooperation and capacity-building activities such as under the ITCP; and
- development of a feedback mechanism to enable lessons learned on implementation of measures to be collated and shared through a possible information exchange on best practice.
Which candidate long-term measures are included in the initial strategy?
Candidate long-term measures - the following candidate measures represent possible long-term further action of the Organization on matters related to the reduction of GHG emissions from ships:
- pursue the development and provision of zero-carbon or fossil-free fuels to enable the shipping sector to assess and consider decarbonization in the second half of the century; and
- encourage and facilitate the general adoption of other possible new/innovative emission reduction mechanism(s).
Studies and reports
Fourth IMO GHG Study
The Fourth IMO GHG Study was submitted to the Marine Environment Protection Committee (MEPC) in July 2020, as document MEPC 75/7/15 - the study can be downloaded via the IMODOCS website (registration required).
The terms of reference for the Fourth IMO GHG Study were agreed by MEPC 74 (May 2019).
The study includes:
- Inventory of current global emissions of GHGs and relevant substances emitted from ships of 100 GT and above engaged in international voyages. The inventory should include total annual GHG emission series from 2012 to 2018, or as far as statistical data are available.
- GHGs are defined as the six gases initially considered under the UNFCCC process: carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O), hydrofluorocarbons (HFCs), perfluorocarbons (PFCs) and sulphur hexafluoride (SF6). The inventory should also include other relevant substances that may contribute to climate change, including Black Carbon (BC).
- Estimates of carbon intensity (estimates of world fleet's CO2 emissions per transport work, from 2012 to 2018, or as far as statistical data are available).
- Possible estimates of carbon intensity of international shipping for the year 2008 (the baseline year for the levels of ambition identified in the Initial Strategy).
- Scenarios for future international shipping emissions 2018-2050
The IMO fourth GHG study was contracted to a CE Delft-led consortium.
The Steering Committee established to act as a focal point for MEPC, to review and monitor progress and confirm that the Study meets the terms of reference, was composed of the
following 13 Member States: Belgium, Brazil, Canada, China, Denmark, Japan,
the Netherlands, Norway, Panama, the Republic of Korea, Singapore, Turkey and the United
States. Mr. Harry Conway (Liberia), in his capacity as Vice-Chair of the Marine Environment
Protection Committee, acts as the Coordinator of the Steering Committee.
Completed reports and studies:
(The views and conclusions expressed in the studies are those of the authors)
Studies and reports can be found here. They include: