Decarbonising Global Shipping: Is The IMO Net-Zero Framework Enough?

The International Maritime Organization has agreed on the world’s first legally binding Net-Zero Framework for shipping, which introduces a global fuel standard and a pricing mechanism for greenhouse gas emissions. The framework marks progress, but critics say it falls short in ambition.

by Tran Bui

The Marine Environment Protection Committee (MEPC) of the International Maritime Organization (IMO) met in London from 7 to 11 April 2025 for its 83rd session (MEPC 83), marking a significant step towards creating a legally binding framework to reduce global greenhouse gas (GHG) emissions in the shipping industry [1]. 

The IMO Net-zero Framework is the first in the world to include measures on a global fuel standard to reduce GHG intensity and a global pricing mechanism for emissions [1]. 

A result years in the making

As the backbone of international trade, the shipping industry plays a vital role in global economies  [2]. However, it is a major contributor to climate change, responsible for almost 3% of global GHG emissions – equivalent to that of the aviation industry [3]. Despite this, the industry’s environmental impact has long been overlooked [4]. As most shipping emissions occur in international waters, coordinated efforts are required to clean up the industry [2].

Against this backdrop, the IMO has been developing regulation over the past decade which has finally culminated in the IMO Net-zero Framework [4].

• In 2011, the IMO rolled out the Energy Efficiency Design Index (EEDI) and the Ship Energy Efficiency Management Plan (SEEMP) as mandatory energy efficiency measures for ships [4, 5].
• In 2018, Member States agreed on the Initial IMO Strategy on Reduction of GHG Emissions from Ships [4, 6].
• In 2023, building on progress from 2018, the IMO Strategy ramped up and set clear goals: reduce emissions by at least 20% by 2030 and by 70% by 2040 (2008 baseline), and phase in zero or near-zero (ZNZ) emission fuels [4, 7].
• In 2025, the IMO Net-zero Framework was approved at MEPC 83 in London [1].

Under the framework, which is set to be adopted in October 2025, large ocean-going ships above 5,000 gross tonnes will be required to comply with:

1. Global fuel standard: Ships must reduce, over time, their annual greenhouse gas fuel intensity (GFI) – that is, how much GHG is emitted for each unit of energy used [1]. The measure covers the full lifecycle of fuel-related GHG emissions to prevent emissions “spilling over” into calculations for other sectors, and to encourage sustainable investments in the shipping industry [8].
2. Global pricing mechanism: Ships emitting above GFI thresholds will be required to offset their emissions by transferring surplus compliance units from other ships, by using surplus units banked from previous reporting periods, or by acquiring remedial units through investments in the IMO Net-Zero Fund [1]. The revenues from the fund will support low-carbon fuel development, capacity building, technology transfer, and assist developing countries, in particular SIDs and LDCs,  in mitigating climate risks [1]. 

Too little, too late – is the IMO Net-Zero Framework enough?

Although the agreement passed with support from 63 countries, including most of the European Union, Canada, China, and India, it has not been without controversy [9]. 16 countries opposed it, including Saudi Arabia, Russia, and Venezuela [9]. Another 25 countries abstained, including some small island nations that said the deal was too weak to meet the IMO green targets of reducing emissions by at least 20% by 2030 and by 70% by 2040 [7, 9].

The World Shipping Council called this an “unprecedented global agreement” that marked “a critical next step toward shipping decarbonization”, and European Shipowners stated that “it is a framework which we can build upon to ensure the necessary investment in the production of clean fuels” [10, 11]. Meanwhile, leaders from the Pacific expressed their “deep disappointment in the outcome” of the MEPC 83, “refusing to support an agreement that would do too little, too late to cut shipping emissions and protect their islands” [12]. 

Elissama Menezes, Director of Equal Routes, argued that “even with the heavy lifting done by small island developing nations, and least developed nations, the IMO continues to protect the status quo” [13]. She warned that “by refusing to take a clear stand on 1.5 alignment, the IMO is risking both climate credibility and its relevance in the global energy transition” [13]. 

Environmental campaigners and leaders from the Pacific are particularly concerned about the lack of net-zero targets in the new IMO Framework and the inclusion of biofuels, which they argue could undermine the IMO’s climate goals [9, 14]. Specifically, the framework only requires ships to account for direct GHG emissions from a biofuel’s life cycle, providing an incomplete picture of its climate impact, particularly as the production of biofuels often requires significant land-use change, which also causes emissions [9, 14]. 

Moreover, early analysis by Transport & Environment (an EU umbrella for green transport NGOs) shows the new framework will see IMO’s own GHG reduction targets for 2030, 2040 and 2050 missed by a significant margin [15]. 

A foundation to build on

Notwithstanding these controversies, the IMO Net-Zero Framework makes a clear statement: the maritime industry is committed to moving away from fossil fuels [16]. 

The IMO agreement is a rare case of effective multilateralism in today’s fragmented geopolitical landscape [17]. Imperfect as it is, the framework serves as a necessary foundation upon which more action can be built [18]. It is set to be formally adopted in October 2025 and enter into force in 2027 [1]. 

References:

[1] IMO approves net-zero regulations for global shipping, International Maritime Organization, https://www.imo.org/en/MediaCentre/PressBriefings/pages/IMO-approves-netzero-regulations.aspx, accessed on 22 May 2025. 
[2] Climate impact of shipping, Transport & Environment, https://www.transportenvironment.org/topics/ships/climate-impact-shipping, accessed on 22 May 2025.
[3] Fourth Greenhouse Gas Study 2020, International Maritime Organization, https://www.imo.org/en/OurWork/Environment/Pages/Fourth-IMO-Greenhouse-Gas-Study-2020.aspx, accessed on 22 May 2025.
[4] Laura Quinones, A historic course correction: How the world’s shipping sector is setting sail for net zero, UN News, https://news.un.org/en/story/2025/05/1163241, accessed on 22 May 2025.
[5] Improving the energy efficiency of ships, International maritime Organization, https://www.imo.org/en/OurWork/Environment/Pages/Improving%20the%20energy%20efficiency%20of%20ships.aspx, accessed on 22 May 2025.
[6] International Maritime Organization, Note by the International Maritime Organization to the UNFCCC Talanoa Dialogue: ADOPTION OF THE INITIAL IMO STRATEGY ON REDUCTION OF GHG EMISSIONS FROM SHIPS AND EXISTING IMO ACTIVITY RELATED TO REDUCING GHG EMISSIONS IN THE SHIPPING SECTOR, UNFCCC, https://unfccc.int/sites/default/files/resource/250_IMO%20submission_Talanoa%20Dialogue_April%202018.pdf, accessed on 22 May 2025.
[7] 2023 IMO Strategy on Reduction of GHG Emissions from Ships, International Maritime Organization, https://www.imo.org/en/OurWork/Environment/Pages/2023-IMO-Strategy-on-Reduction-of-GHG-Emissions-from-Ships.aspx, accessed on 22 May 2025.
[8] Landmark agreement towards achieving net-zero emissions from global shipping by 2050, Directorate-General for Mobility and Transport, https://transport.ec.europa.eu/news-events/news/landmark-agreement-towards-achieving-net-zero-emissions-global-shipping-2050-2025-04-11_en, accessed on 22 May 2025.
[9] Jennifer L, Shipping Toward Net Zero Needs $1 Trillion: What’s Inside the IMO’s New Framework, Carbon Credits, https://carboncredits.com/shipping-toward-net-zero-needs-1-trillion-whats-inside-the-imos-new-emissions-framework/, accessed on 23 May 2025.
[10] Unprecedented global agreement gives shipping clarity on critical next step to decarbonization, World Shipping Council, https://www.worldshipping.org/news/unprecedented-global-agreement-gives-shipping-clarity-on-critical-next-step-to-decarbonization, accessed on 23 May 2025.
[11] European Shipowners welcome important global agreement on shipping decarbonisation, European Community Shipowners’ Associations, https://ecsa.eu/european-shipowners-welcome-important-global-agreement-on-shipping-decarbonisation/, accessed on 22 May 2025.
[12] Island Ministers Abstain In Vote On Weak Deal On Emissions Pricing At International Maritime Organization, Micronesian Center for Sustainable Transport, https://mcstrmi.org/breaking-stories/island-ministers-abstain-in-vote-on-weak-deal-on-emissions-pricing-at-international-maritime-organization/, accessed on 22 May 2025.
[13] IMO Climate Agreement Shipwreck Misses Targets and Betrays Most Vulnerable, Clean Shipping Coalition, https://cleanshipping.org/news/imo-climate-agreement-shipwreck-misses-targets-and-betrays-most-vulnerable/, accessed on 23 May 2025.
[14] International Council on Clean Transportation, ‘Four changes would make the IMO Net-Zero Framework more effective’, <https://theicct.org/four-changes-would-make-the-imo-net-zero-framework-more-effective-apr25/>, accessed on 28 May 2025.
[15] IMO Net-Zero Framework: Assessing the impact of the IMO’s draft Net-Zero Framework, Transportation & Environment, https://www.transportenvironment.org/uploads/files/Impact-of-the-IMOs-draft-Net-Zero-Framework-April-2025.pdf, accessed on 23 May 2025.
[16] First Global Carbon Pricing Scheme Approved for Shipping, Deutsche Gesellschaft für Internationale Zusammenarbeit (GIZ) GmbH, https://changing-transport.org/first-global-carbon-pricing-scheme-approved-for-shipping/, accessed on 23 May 2025.
[17] Phase-out of fossil fuels in shipping begins in earnest: IMO measures unlikely to reach GHG reduction targets, but close the LNG business case and send clear long run signal for hydrogen-derived fuels, UCL Shipping and Oceans Research Group, https://www.shippingandoceans.com/post/phase-out-of-fossil-fuels-in-shipping-begins-in-earnest, accessed on 22 May 2025.
[18] Bastien Bonnet-Cantalloube, Watering down already weak IMO compromise will sink shipping’s climate ambition, Carbon Market Watch News, https://carbonmarketwatch.org/2025/05/15/watering-down-already-weak-imo-compromise-will-sink-shippings-climate-ambition/, accessed on 23 May 2025.