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.