Deployment of all currently known technologies could make it possible to almost completely decarbonize maritime shipping by 2035, according to a new report published by the International Transport Forum at the OECD.

Four different decarbonization pathways examined for the study would reduce international shipping’s CO₂ emissions between 82% and 95% below the level currently projected for 2035. This reduction equals the annual emissions of 185 coal-fired power plants.

Remaining CO₂ emissions would be between 44 and 156 million tonnes in 2035. This compares to a business-as-usual scenario in which carbon emissions from international shipping are projected to increase 23% to 1090 million tonnes by 2035 compared to the 2015 level.

• Alternative fuels and renewable energy can deliver much of the required reductions. Currently available biofuels should be complemented by other natural or synthetic fuels such as methanol, ammonia and hydrogen. Wind assistance and electric propulsion have shown that they can bring additional reductions.

• Technological measures to improve the energy efficiency of ships could yield a substantial part of the needed emission reductions. Market-mature options include, among others, hull design improvements, air lubrication and bulbous bows.

• Operational improvements such as slower ship speeds, smoother ship-port co-ordination and use of larger, more efficient ships could bring further, important emission reductions.

The report recommends:

• Setting a clear, ambitious emissions-reduction target to drive decarbonization of maritime transport;

• Supporting the realization of emissions-reduction targets with a comprehensive set of policy measures; and

• Providing smart financial incentives to advance decarbonization of maritime shipping.

The work for the report was carried out with support from the European Climate Foundation.