Four different decarbonization pathways examined for the study would reduce international shipping’s CO2 emissions between 82 and 95 percent below the level currently projected for 2035. This reduction equals the annual emissions of 185 coal-fired power plants.
Alternative fuels and renewable energy can deliver much of the required reductions. Currently available biofuels could 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.
