When delegates from more than 170 countries gather at the International Maritime Organization’s London headquarters from April 20 to 24, the European Union plans to arrive with draft rules for a global carbon levy on shipping, according to a Council of the European Union agenda document circulated to member states. The United States has already declared it will fight the measure, calling it a “global carbon tax” that threatens American consumers. The standoff is the sharpest transatlantic confrontation over climate policy since Washington pulled out of the Paris Agreement, and its outcome will shape the cost of moving goods across every ocean.
What the EU is bringing to the table
The Council document, coded CM 1637/26, shows that the EU’s Working Party on Shipping has placed detailed preparatory items on its agenda for the upcoming IMO session. Those items include draft Union submissions on chain-of-custody rules for marine fuels, life-cycle assessment guidelines, and greenhouse gas fuel intensity standards. These are not statements of principle. They are the technical plumbing that would make a carbon levy enforceable: how to measure emissions, how to verify that a ship burned the fuel it claims, and how to set a declining cap on carbon intensity over time.
The preparations build on a political commitment the EU made in April 2025, when the European Commission welcomed an IMO agreement reached at the body’s 83rd Marine Environment Protection Committee session. That agreement established a net-zero target for international shipping by 2050, consistent with the IMO’s 2023 greenhouse gas strategy. Brussels endorsed it as a foundation for a single global carbon pricing mechanism, arguing that one worldwide rule would prevent the patchwork of regional schemes that could distort trade routes and freight pricing.
The EU is not starting from scratch on maritime carbon pricing. The bloc began phasing shipping into its Emissions Trading System in January 2024, requiring vessels calling at European ports to surrender allowances for a share of their voyage emissions. That system is already adding costs on routes touching Europe. A global IMO levy, if adopted, would raise a question Brussels has not yet publicly answered: whether the EU’s own scheme would be adjusted, replaced, or layered on top of the international one.
Why Washington is pushing back
The U.S. position was staked out in an August 2025 joint statement from the Department of Commerce, issued during President Trump’s second term. The statement names the IMO’s Net-Zero Framework directly, characterizes it as a global carbon tax, and warns of “retaliation and remedies” if the initiative advances. The language goes beyond diplomatic disagreement. It puts trading partners on notice that Washington views the levy as an economic threat, not an environmental tool.
What the statement does not do is specify what retaliation would look like. It offers no economic modeling of the levy’s impact on American exporters or importers, no legal analysis of how U.S. law would interact with an IMO-mandated charge, and no timeline for countermeasures. The threat is political, not operational, which leaves the scale of potential disruption open to interpretation. Possible responses could range from tariffs on goods carried by levy-paying vessels to a simple refusal to comply with IMO reporting requirements, but none of those options has been formally proposed.
The opposition also reflects a broader pattern. The Trump administration has moved to roll back domestic climate regulations and has signaled skepticism toward multilateral environmental agreements. Framing a shipping levy as a tax on consumers fits that posture, positioning the U.S. as a defender of affordability against what it portrays as European regulatory overreach.
The gaps that will define the negotiations
For all the clarity of the two sides’ positions, the most consequential details remain unresolved. The IMO has not published a proposed rate per ton of CO2. Earlier proposals from nations including the Marshall Islands and the Solomon Islands have floated figures around $100 per ton, but no consensus number is on the table. Without a rate, it is impossible to calculate how much shipping costs would rise on any given trade lane, or how much revenue the levy would generate for a fund intended to help developing countries transition to cleaner fuels.
The positions of other major maritime powers are also unclear in the public record. China, the world’s largest exporter by cargo volume, has historically resisted binding carbon pricing at the IMO while supporting less prescriptive measures. How Beijing lines up in April will matter as much as the EU-U.S. divide, because IMO decisions require broad consensus to stick.
Industry voices are notably absent from the institutional documents on both sides. Neither the EU’s Council agenda nor the U.S. Commerce statement includes direct input from major carriers, port authorities, or trade associations. Shipping companies and charterers would be the ones actually paying a levy, and their operational responses, such as rerouting, slow-steaming, or passing costs to cargo owners, will determine how the policy hits supply chains in practice. The International Chamber of Shipping has previously supported a carbon levy in principle but pushed for a lower rate and a simpler structure than what some governments have proposed.
International shipping accounts for roughly 3% of global CO2 emissions, a share comparable to Germany’s entire national output. The sector has been one of the hardest to decarbonize because ships burn heavy fuel oil on voyages that can last weeks, and alternative fuels like green methanol and ammonia remain expensive and scarce. A carbon levy is designed to close that cost gap by making fossil fuels more expensive, but the transition depends on the levy being high enough to change behavior and stable enough for shipowners to justify investing in new vessels and fuel infrastructure.
What the April session will signal
The most reliable indicator of where this dispute is heading is not the rhetoric from either capital but the institutional paper trail. The EU’s progression from a political endorsement in April 2025 to draft technical submissions in early 2026 shows a government preparing to negotiate implementation details, not to debate whether a levy should exist. The presence of items like fuel traceability and life-cycle methodology on the Council agenda suggests European negotiators will arrive in London with near-final text on key technical questions.
The U.S., by contrast, has so far operated at the level of first-order objections: the levy is a tax, it hurts consumers, and there will be consequences. Until Washington publishes more granular proposals or counteroffers, its position functions as a political red line rather than a mapped-out negotiating strategy.
That asymmetry will be tested in the working group sessions. If the EU tables detailed rule text and the U.S. responds only with broad opposition, other delegations may gravitate toward the more developed proposal simply because it gives them something concrete to amend. If Washington brings its own alternative, perhaps a fuel standard without a price mechanism, or a voluntary framework, the talks could fracture along different lines entirely.
For companies that ship goods and consumers who buy them, the practical question is whether the world’s oceans will be governed by a single carbon price, a collision of competing regional regimes, or a stalemate that delays decarbonization while costs accumulate in other ways. The answer will start to take shape in London this April.
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*This article was researched with the help of AI, with human editors creating the final content.
