The United States has intensified its campaign against the International Maritime Organization’s (IMO) proposed Net Zero Framework, threatening sweeping penalties against nations, companies and officials supporting the measure. Yet despite Washington’s escalation, the initiative to impose the first global carbon levy on shipping appears set to pass, with broad backing from China, the EU, India and the United Kingdom, among others.
The IMO’s Marine Environment Protection Committee convened in London this week to finalise the framework, which aims to impose a carbon price on vessels exceeding 5,000 GT. The policy is expected to raise up to $15bn annually from 2030, directing funds towards decarbonisation projects across the industry.
The Trump administration warned that adoption of the framework would trigger retaliatory measures. A joint statement from US secretary of state Marco Rubio, energy secretary Chris Wright and transportation secretary Sean Duffy threatened sanctions on officials ‘sponsoring activist-driven climate policies’, new port fees and even restrictions on vessels linked to supporting nations. The statement also hinted at visa and employment restrictions for seafarers and limits on commercial contracts involving flag states in favour of the IMO deal.
‘The US will fight hard to protect our economic interests by imposing costs on countries if they support the NZF,’ the officials said. The administration described the proposal as a ‘European-led neo-colonial export of global climate regulations’.
European policymakers, however, have refused to back down. The European Commission reaffirmed its support for the IMO framework, describing it as a ‘significant milestone’ in creating a level playing field for maritime decarbonisation. Brussels has indicated that its regional carbon pricing schemes, including the EU ETS and FuelEU Maritime, could be revised once a global mechanism takes effect.
There are, however, tensions within the EU bloc. Greek shipping minister Vassilis Kikilias said the IMO text contained ‘serious problems, ambiguities and unrealistic targets’, warning that compliance could add up to €300bn in costs by 2035. Greek shipowners have also voiced concern that the plan disadvantages LNG-fuelled tonnage, potentially making conventional fuel oil more economical even after tax penalties.
Despite these divisions, momentum behind the global carbon tax has grown. A breakthrough earlier this year saw 63 IMO members, including major economies such as China, Brazil, India and the UK, endorse the draft text. Only 16 nations, largely fossil fuel exporting nations, opposed it. Several Pacific island states that previously abstained have now pledged support, tipping the balance further in favour of adoption.
The International Chamber of Shipping, representing over 80% of the global merchant fleet, said it was confident the framework would be approved. IMO secretary-general Arsenio Dominguez has urged members to act decisively, warning that failure could lead to a proliferation of fragmented regional measures, increasing compliance burdens for shipowners.
Supporters see the Net Zero Framework as a landmark for global climate diplomacy, particularly in light of growing scepticism from Washington. Emma Fenton, senior director for climate diplomacy at Opportunity Green, said the deal would demonstrate that ‘climate multilateralism is still alive and well in spite of the open hostility’ from the US.
If adopted, the IMO’s carbon levy would represent one of the most significant climate measures since the start of Donald Trump’s second term, signalling that international cooperation on maritime decarbonisation remains possible despite political headwinds. For the shipping industry, the decision will shape not only the cost of trade but also the trajectory of investment in low-carbon fuels, onboard carbon capture and green infrastructure in the decade ahead.
