Currently known and mature energy efficiency measures can reduce emission per ship by 20 - 30%, dependent on ship type. This does not include speed reduction.
Future fuels for shipping need to have a zero or near-zero carbon footprint.
Moderate to extensive speed reduction (20 - 50% reduction) is technically feasible, but requires commercial acceptance and a restructuring of the logistics system.
Reducing SOx and NOx emissions and treating ballast water will increase energy use in shipping. Ballast water treatment, distillates, scrubbers, catalyzers and exhaust gas circulation are all measures that increases energy need. Addressing local pollution and transfer of alien species is necessary, but over time the emphasis will increasingly be on GHG. All pollutants must be addressed in future designs.
DNV GL believes a trajectory for shipping resulting in a 50% reduction in CO2 emissions by 2050 compared to 2008 is ambitious. It will require application of currently immature technology and solutions, acceptance of lower speed and deployment of large volumes of zero-carbon or carbon-neutral sustainable fuels. Significantly reducing emissions will increase cost of transportation, but solutions will not be applied if they are too costly. The key to achieving reduction of emission is developing, maturing and scaling up solutions to a level where the cost is acceptable. Regulations should be supplemented by other policy measures and incentives to drive technology development and emission reductions, while at the same time ensuring the shipping activity is not restricted. Temporary offset mechanisms may be needed to allow flexible means of compliance, and ensure reductions where it is most cost-effective.