Shipping companies would have to pay a small levy on every tonne of fuel they use under proposals aimed at developing zero-carbon vessels within 10 years, transforming the high-carbon global shipping business.

Ships running on hydrogen or ammonia as fuel are thought to be technically possible, but more research and development is needed to bring forward the development of prototypes.

The International Chamber of Shipping (ICS), which represents 80% of the global shipping industry, is proposing a $2 levy on every tonne of fuel consumed by ships, raising $500m a year that would be devoted to research and development of zero-carbon vessels.

“This is a very positive proposal,” said Guy Platten, the secretary general of the ICS. “We need to get to zero carbon [for shipping] and this is a transparent mechanism for raising funds that we need to help us do that. We have worked for years on this with the support of our members.”

Fuel costs about $400 a tonne at present, set to rise to an estimated $600 next year following the introduction of new regulations on cutting sulphur emissions from ship oil. The $2 levy is small in comparison, and Platten said it was kept low so that developing countries would see it as affordable, but it would still raise enough to fund the development of a new generation of ships in a decade or so.

Simon Bennett, the ICS’s deputy secretary general, said shipowners could foresee that they would be pressed to further cut greenhouse gases, and that without a coherent plan to move to zero emissions in the next few decades it was likely that “something far worse” could be imposed. That could feasibly include rationing emissions for maritime transport in the next 20 to 30 years.

Bennett said it was vital the levy plan was a mandatory, rather than voluntary, initiative.

Some campaigners were cautious about the proposal, which will not produce concrete reductions in emissions in the short term.

Doug Parr, the chief scientist at Greenpeace UK, said: “The shipping industry has slipped under the radar of international climate action for way too long. Investing research to create zero-carbon ships is not a bad thing in itself, but it becomes suspiciously close to a delaying tactic if it is not accompanied by clear reduction targets. If the shipping industry wants people to believe this is a serious move, then they should change course and support legally binding targets to cut their planet-warming emissions.”

Nico Muzi, the director of communications and campaigns at Transport & Environment, said: “That amount is simply ridiculous to spur innovation in the sector nor to be a driver to spur efficiency. If it is $2 per tonne of fuel, it is 42 times less than current CO 2 prices in Europe. To rein in long-ignored maritime emissions and make shipping do its fair share, Europe must bring shipping into its carbon market and mandate CO 2 standards for all ships calling at its ports.”

Shipping accounts for about 2% of global greenhouse gases, and the share is likely grow further as trade increases and other sectors, such as electricity generation and land transport, reduce carbon.

Despite the size of the sector, progress on cutting emissions has so far been slow. Shipping and aviation have been omitted from global climate talks and commitments on cutting carbon for the last two decades, and national commitments under the 2015 Paris agreement do not include the international transport sectors.

Fairtransport ship Tres Hombres, which transports coffee for Shipped by Sail. Photograph: Handout

Action from within the shipping sector has also been slow. The International Maritime Organisation is seeking to halve shipping emissions by 2050, a mammoth task as emissions have continued to rise while the issue was ignored, while countries including the UK are seeking net-zero emissions by the same deadline.

Shipping fuel is particularly carbon-intensive, as ships use heavy fuel oil that is dirty and high in contaminants as well as carbon. Sulphur from shipping is also a problem, and subject to separate regulations.

The ICS put forward its paper to the International Maritime Organisation on Wednesday, with a view to incorporation into maritime regulations within a few years. The paper will be introduced at a key IMO meeting next March, then discussed again through the year, and if accepted by member states would be added to existing international maritime conventions.

Bennett said the shipping industry would be capable of halving emissions by 2050 only if a large proportion of the global fleet was using zero-carbon fuels. He predicted that the rest of the fleet could be converted soon after, bringing the goal of 100% decarbonisation closer.

He said the initiative would not affect potential proposals to bring shipping within the scope of the EU’s emissions trading scheme.