A delay in charging a global shipping emissions tax could stall critical investments in green fuels, and cause decarbonization efforts across the industry to slow, warned industry stakeholders at a ocean conservation and sustainable shipping conference.

"We were disappointed that this did not go through," said Marco Romero, a decarbonization specialist with risk management firm DNV, speaking at 2025's One Ocean Week conference in Seattle, Washington, on October 21. "We were looking for something that would harmonize the global approach."

In April, the United Nations member states approved the initial draft of the IMO's policy Net-Zero Framework (NZF), which would mean imposing a global shipping emissions tax from 2028 in order to fund cleaner maritime technologies and help developing nations transition to low-carbon shipping. The NZF also set goals to cut annual carbon emissions from international shipping by at least 20% by 2030, and 70% by 2040, and then finally reach net-zero emissions by 2050. 

But, on October 17, all members of the International Maritime Organization (IMO) voted to postpone a vote on passing the NZF until late 2026. The pullback came a day after President Donald Trump criticized the plan as a "global green scam tax on shipping," and threatened to impose port levies and sanctions against any nations that supported it. 

Although pressure from the U.S. is significant, the controversy surrounding the Net-Zero Framework extends well beyond Trump's objections, delegates at the conference said. 

"There is a coalition of groups that had concerns — some of them very valid, and some of them very rooted in practicality," said Romero.

Some groups were critical of the framework for its inclusion of biofuels as a low-carbon alternative to fossil fuels, pointing to how the production of biofuels still releases carbon through deforestation and intensive farming practices. Others claimed that the NZF wasn't ambitious enough to meet any of the emissions benchmarks it had set along the path to net-zero. 

In any case, delaying the NZF could end up being a double-edged sword, Romero said. On one hand, it provides an opportunity for the industry to reconvene and address any outstanding concerns. On the other hand, the NZF will still have the same emissions benchmarks to hit, regardless of the delay. "What we lost is the mechanism to get there," Romero explained.

As deliberations over the framework continue in 2026, Romero stressed the need for individual stakeholders, countries and regions to continue taking steps to develop cleaner fuels and reduce emissions themselves. Ultimately, that collective effort will be critical in bridging the gap created by the IMO's delay.

"We can be disappointed by the outcome, but we can be energized by the outcome as well, and we can figure out a way forward together," he said.