A new measure for the MARPOL convention -- which covers global shipping and fishing vessels -- has been proposed, intended to reduce greenhouse gas emissions from commercial activities at sea, according to the UN's International Maritime Organization (IMO).

The joint proposal, which has received the backing of 47 governments, would see a pricing mechanism whereby vessel owners would pay a fee per metric ton of greenhouse gas emitted to the multi-billion-dollar IMO fund.

The aim would be to reduce the price gap and incentivize the uptake of zero/near-zero (ZNZ) emission marine fuels such as green methanol, ammonia and hydrogen.

Although an official pricing figure has not been agreed, the IMO said it is likely to fall in the range of $60-$300/t of conventional marine fuel oil consumed, "depending on the agreed reward rate for the use of ZNZ greenhouse gas marine fuels and the level of revenue to be allocated annually to support developing countries."

Revenue generated through the system would be used to reward the production and uptake of ZNZ fuels, as well as support the maritime emission reduction schemes of developing countries.

"The industry fully supports the adoption by IMO of a greenhouse gas pricing mechanism for global application to shipping," said Guy Platten, secretary general of the International Chamber of Shipping (ICS). "The joint text put forward by this broad coalition is a pragmatic solution and the most effective way to incentivize a rapid energy transition in shipping to achieve the agreed IMO goal of net zero emissions by or close to 2050."

"We are very pleased that such a large and diverse group of nations now firmly supports a common approach to maritime carbon charging," he added. "This proposed joint text has been hard fought and is broadly based on ideas which ICS has been advocating for the past 10 years."

The new proposal will be considered by a critical IMO meeting in the week of Feb. 17. If the MARPOL amendments are approved by IMO in April this year, they should enter into force globally in early 2027, with the collection of annual emission contributions from ships commencing in 2028.

The 47 backers include EU member states, the UK, Ukraine, Georgia, South Korea, Japan, Nigeria, Kenya, and various island nations in the Caribbean, Indian Ocean and Pacific.

The US, China, Russia and India are not part of the initial group of backers, and Platten noted there would still be work ahead if the proposal is to come into force. 

"While a large number of governments now support a universal flat rate GHG contribution by ships -- or something similar -- a minority of governments continue to have concerns," he said. "Working in co-operation with all IMO member states, we will do our best to allay such concerns during the final stages of these critical negotiations about regulatory text."