US threatens retaliation over carbon tax on ocean shipping

Washington says IMO plan would ignite global inflation

(Photo: IMO)

The United States is threatening to take action against nations that agree to a global carbon tax on ocean shipping.

Member states of the International Maritime Organization are meeting in London this week to discuss an agreement on decarbonization of seagoing vessels by 2050.

The IMO has proposed a per-ship penalty of as much as $150 per ton of particulate emissions. Supporters say this is the most effective means to narrow the cost gap between diesel and alternative fuels such as methanol, ammonia and liquefied natural gas. Opponents claim those charges could double fuel prices for container ships and raise costs for the United States, the world’s largest market for containerized imports.

Washington in a statement to IMO members called the carbon tax an economic burden that would drive global inflation, and called for a halt to negotiations by the United Nations agency. The statement threatened reciprocal measures against nations that agree to the tax but did not offer further details.

The U.S., which is not attending the meeting, had been a longtime proponent of the decarbonization plan, most recently under the Biden administration. 

At the same time, the IMO was reportedly losing support for its proposal amid efforts by China and Middle East nations that favor a cap-and-trade system of credits over a carbon tax.

The U.S. statement was first reported by Lloyd’s List.

Find more articles by Stuart Chirls here.

Related coverage:
United States reverses course on proposed port fees for Chinese ships

Ocean shipping carbon tax could gouge US consumers, say opponents 

Expect ‘subdued’ peak container season in wake of tariffs, says analyst

Port of LA’s Seroka says tariffs to cut container volumes by 10%

Upcoming FreightWaves Events
AI

Supply Chain AI Symposium

Past the hype. Join operators, founders, and enterprise leaders figuring out how to deploy AI in supply chain.

July 15, 2026
The Old Post • Chicago, IL
Register Now
FreightTech

F3: Future of Freight Festival

Industry-defining keynotes, rapid-fire technology demos, and industry leaders networking in experiences across Chattanooga - plus the inaugural F3 Awards Dinner featuring the FreightTech and Shipper of Choice reveals.

October 27, 2026 – October 28, 2026
The Signal at Chattanooga Choo Choo • Chattanooga, TN
Register Now
AI Supply Chain AI Symposium Jul 15 • The Old Post • Chicago, IL

Past the hype. Join operators, founders, and enterprise leaders figuring out how to deploy AI in supply chain.

The Old Post • Chicago, IL Register Now
FreightTech F3: Future of Freight Festival Oct 27 – Oct 28 • The Signal at Chattanooga Choo Choo • Chattanooga, TN

Industry-defining keynotes, rapid-fire technology demos, and industry leaders networking in experiences across Chattanooga - plus the inaugural F3 Awards Dinner featuring the FreightTech and Shipper of Choice reveals.

The Signal at Chattanooga Choo Choo • Chattanooga, TN Register Now

Stuart Chirls

Stuart Chirls is a journalist who has covered the full breadth of railroads, intermodal, container shipping, ports, supply chain and logistics for Railway Age, the Journal of Commerce and IANA. He has also staffed at S&P, McGraw-Hill, United Business Media, Advance Media, Tribune Co., The New York Times Co., and worked in supply chain with BASF, the world's largest chemical producer. Reach him at stuartchirls@firecrown.com.