Strong global policy is needed to change sustainable shipping fuel economics, writes Michael Ball
Significant work remains to transition the world away from fossil fuel in aviation and shipping, despite repeated support pledged at UN climate talks.
The need to ramp up the use of alternative fuels will be a focus of the UN's Cop 31 climate summit next month in Antalya, Turkey. The host wants countries to join a new pledge to boost electricity to 35pc of all global final energy consumption by 2035, up from about 20pc currently.
Last year's host, Brazil, has its own initiative to quadruple global output and use of sustainable fuels, including biofuels, by 2035. And past Cops have produced other pledges to reduce emissions in aviation or shipping. But alternative fuels have not yet reached their tipping point, accounting for less than 1pc of the fuel used in aviation or shipping globally. Cost and politics remain two of the major roadblocks.
The sustainable aviation fuel (SAF) industry has shown signs of growth. Major fuel users, including Delta Airlines and FedEx, have recently extended and expanded SAF offtake agreements.
And production is on the rise. For example, Neste, the leading producer of SAF, currently has production capacity of 1.5mn t/yr, which it plans to grow to 2.2mn t/yr in 2027, or about 750mn USG. But SAF still makes up a small, but growing, sliver of fuel use. Suppliers in the EU blended nearly 3pc into jet fuel last year, surpassing the bloc's 2pc mandate in its first year. In the US, SAF accounts for roughly 1pc of jet fuel supply, although the US EIA expects that to soon reach about 2pc. Global production this year is set to exceed 790mn USG, up by 26pc on the year, according to the International Air Transport Association.
The story is similar in shipping. Globally, ships of at least 5,000 gross tonnage used more than 223mn t of fuel oil in 2024, about 92.5pc of which came from heavy fuel oil, light fuel oil or diesel, according to International Maritime Organization (IMO) data. Only about 0.8pc came from "other" fuels, despite biofuels jumping to more than 1.2mn t from less than 400,000t in 2023.
But the slow pace of fleet turnover, and the need for more engines that can use alternatives, means that the course the industry plots over the next few years could determine whether it can meet the IMO's goal of net zero emissions by 2050, according to a recent report from the Global Centre for Maritime Decarbonisation (GCMD).
Cost calculations
Cost remains a major hurdle to greater SAF use in aviation and shipping. SAF can reduce emissions under the International Civil Aviation Organisation's Carbon Offsetting and Reduction Scheme for International Aviation (Corsia) system, which seeks to offset any growth in aviation CO2 above 85pc of 2019 levels. But using Corsia carbon offsets currently costs significantly less.
Argus assessed Corsia phase 1 credits at $12.45/t this week, compared with an abatement cost as high as $310/t for the US west coast. In other parts of the world, the cost of abating 1t of CO2 equivalent in emissions by using SAF instead of jet fuel is even higher.
In shipping, GCMD says strong global policy is needed to change the economics of sustainable fuels, as national and sub-national efforts will fall short. At the top of the list is the IMO-proposed carbon pricing system, the adoption of which was delayed last year in the face of US opposition. IMO pledged to try again this year. The agency will meet next month to consider next steps toward achieving its greenhouse gas emissions goals. "Achieving a price signal of this magnitude will be challenging, but without it, the economics are unlikely to support the transition to new fuels at scale," the GCMD said.
