Are the IMO’s new targets for international shipping compatible with the Paris Climate Agreement?

International shipping is a major contributor to climate change. The International Maritime Organization (IMO) has jurisdiction over the sector’s efforts to reduce greenhouse gas emissions, and in July 2023 agreed a revised climate change strategy, setting tightened targets for emissions reductions by 2030, 2040 and 2050. In this perspective article, we analyse the remaining carbon budgets available to the international shipping sector, to assess whether these new targets constitute a sufficient contribution to meeting the overarching Paris Agreement goal to limit global heating to 1.5°C. The new strategy sets both ‘indicative checkpoints’ and more ambitious ‘strive’ targets. Both represent a major advance over the previous strategy, however, only the ‘strive’ targets are compatible with the 1.5°C limit. The first ‘strive’ target is for 30% reductions by 2030, just seven years away. To meet this goal, it is imperative that the IMO, nation states and the shipping industry act immediately to accelerate deployment of known technologies and operational practices that improve energy efficiency and cut CO2 emissions in the existing fleet. The new IMO strategy represents a major improvement on the targets in the previous 2018 strategy.The ‘indicative checkpoint’ targets for 2030 and 2040 are not sufficient for a fair contribution from international shipping to meeting the Paris 1.5°C limit.Under generous assumptions, the ‘strive’ targets of 30% reductions by 2030 and 80% by 2040 are compatible with the 1.5°C limit. These should be considered a minimum level of ambition for the sector.Further delay would push compatibility with 1.5°C out of reach.It is imperative that policy makers and the industry focus on accelerated deployment of known technologies and practices to meet the ‘strive’ 30% goal by 2030. The new IMO strategy represents a major improvement on the targets in the previous 2018 strategy. The ‘indicative checkpoint’ targets for 2030 and 2040 are not sufficient for a fair contribution from international shipping to meeting the Paris 1.5°C limit. Under generous assumptions, the ‘strive’ targets of 30% reductions by 2030 and 80% by 2040 are compatible with the 1.5°C limit. These should be considered a minimum level of ambition for the sector. Further delay would push compatibility with 1.5°C out of reach. It is imperative that policy makers and the industry focus on accelerated deployment of known technologies and practices to meet the ‘strive’ 30% goal by 2030.

国际航运业是气候变化的重要推手之一。国际海事组织（International Maritime Organization，IMO）负责监管该行业的温室气体减排行动，并于2023年7月通过修订后的气候变化战略，设定了2030、2040及2050年的收紧版减排目标。在本评述文章中，我们针对国际航运业可动用的剩余碳预算展开分析，以评估这些新目标是否足以助力实现《巴黎协定》（Paris Agreement）将全球温升控制在1.5°C以内的核心目标。新战略同时设定了「指示性节点目标」与更为激进的「力争目标」。二者相较此前战略均实现了重大突破，但唯有「力争目标」符合1.5°C温升限制的要求。首个「力争目标」要求到2030年减排30%，彼时距当下仅余七年时间。为达成这一目标，国际海事组织、各国政府及航运业必须立即行动，加快部署可提升能源效率、削减现有船队二氧化碳（CO₂）排放的成熟技术与运营方案。国际海事组织的新战略相较2018年版战略，在目标设定上实现了重大改进。2030年与2040年的「指示性节点目标」，不足以让国际航运业为达成《巴黎协定》1.5°C温升限制目标做出公平贡献。在宽松假设前提下，2030年减排30%、2040年减排80%的「力争目标」，符合1.5°C温升限制的要求，应被视为该行业需达成的最低雄心水平。进一步拖延将使符合1.5°C温升限制的目标遥不可及。政策制定者与行业必须聚焦于加快部署成熟技术与运营方案，以在2030年前达成「力争目标」中的30%减排要求。国际海事组织的新战略相较2018年版战略，在目标设定上实现了重大改进。2030年与2040年的「指示性节点目标」，不足以让国际航运业为达成《巴黎协定》1.5°C温升限制目标做出公平贡献。在宽松假设前提下，2030年减排30%、2040年减排80%的「力争目标」，符合1.5°C温升限制的要求，应被视为该行业需达成的最低雄心水平。进一步拖延将使符合1.5°C温升限制的目标遥不可及。政策制定者与行业必须聚焦于加快部署成熟技术与运营方案，以在2030年前达成「力争目标」中的30%减排要求。