IMO Approves Landmark Global Carbon Tax for Shipping Emissions by 2028; US Absent

Major shipping nations, excluding the U.S., have agreed to a minimum $100 tax per ton of carbon dioxide emissions from ships, marking a first-of-its-kind global greenhouse gas emissions tax. The agreement, finalized at the International Maritime Organization (IMO) meeting on April 11, 2025, will take effect by 2028. The tax targets nations that do not meet IMO's net-zero fund contributions or fuel compliance standards. The IMO also established a marine fuel standard to phase in cleaner fuels. While some environmentalists have hailed the decision as historic, concerns remain that it does not capture all emissions or sufficiently aid developing countries in transitioning to greener shipping. Emma Fenton, senior director for climate diplomacy at Opportunity Green, noted the approved measure sets a low bar, and will not ensure sufficient emission reductions or raise the revenues needed for a just and equitable transition. The IMO aims to achieve net-zero emissions from international shipping by or around 2050. The agreement represents a compromise between a simple tax and a credit trading model. The U.S. did not participate in the negotiations, with the previous administration having rejected economic measures based on emissions or fuel choice.