The International Maritime Organization's plan for a global carbon tax on shipping emissions faced a major setback last week. Under pressure from the Trump administration, the meeting adjourned without adoption, postponing the framework by at least a year. This move highlights challenges in international climate cooperation.
The International Maritime Organization (IMO), the United Nations agency overseeing global shipping, had drafted a net-zero framework to push the sector toward cleaner fuels. Shipping handles around 90 percent of global trade and accounts for 3 percent of the world’s emissions, making this a key step in the energy transition. The framework required shippers to pay a fee per ton of greenhouse gas emissions if above a certain threshold, with fees pooled to support alternative fuels and decarbonization in developing countries.
The shipping industry, which made $340 billion in profits from 2019 to 2023 according to Opportunity Green, largely supported the plan for its regulatory certainty. A group of trade organizations stated, “Only global rules will decarbonize a global industry.” Most UN member countries also backed it.
In April 2025, the Trump administration withdrew from IMO negotiations. As a vote approached in October, the US pressured other nations and warned of tariffs, visa restrictions, port fees, and sanctions on officials from countries voting for the framework. President Trump called it a “global green new scam tax on shipping” on Truth Social.
Last week, Saudi Arabia called for adjourning the meeting for one year, which passed 57-49 with 21 abstentions under IMO rules. Observers noted US obstruction as decisive. Em Fenton of Opportunity Green said, “It’s fair to say that the retaliatory measures and punitive threats... played their part,” calling the outcome “a devastating blow for climate multilateralism.”
The framework stemmed from 2023 IMO agreements for net-zero by 2050. Negotiations balanced a carbon-intensity cap with economic measures: a compromise two-tier system allowed high emitters some carbon trading, while lower ones paid a levy per ton, with rewards for zero-emission fuels.
With talks delayed, cities and ports advance initiatives like green shipping corridors and stricter standards. Alisa Kreynes of C40 said, “The cities will continue to push forward with advancing equitable port and shipping decarbonization.” However, these won't address the main emissions from fuel-hungry ships. Fenton warned the delay tactic could appear at COP30, signaling fragility in global cooperation.