The new measurements of carbon intensity for ships have gone into effect. The International Maritime Organization (IMO) created new regulations that went into effect on November 1, 2022. One of the measures is the Carbon Intensity Indicator (CII), intended for existing ships. It’s calculated as CO2 emitted per unit of ship cargo carrying capacity and nautical miles sailed, says DNV, classification society for maritime and an assurance and risk management expert (What is the CII?)
There are two different measures used in the calculation. One is the Annual Efficiency Ratio (AER), the annual emissions per ton mile, for segments where cargo is weight critical. The other is cgDist, emissions per gross ton-miles, for volume-critical cargo.
One of the criticisms of the measure is that it uses distance sailed rather than anything related to the amount of cargo. Actually, as of today, a similar rating using actual cargo carried, the EEOI, can only be reported on a voluntary basis, and may not be substituted for the CII. This has provoked some stern criticism from the large carriers that are heavily loaded, such as Maersk and MSC, though they will comply with the reporting regulation.
But these carriers and others have called for an early reform to the measure, to prevent a ship logging empty miles in order to improve its CII. Emissions are lower when running empty, since you’re not moving the weight of the cargo. So a tanker, for instance, can improve its CII ratio by deadheading back to its pickup point, rather than moving another cargo.
But these concerns are nits compared to the concept of rating all ships by their carbon emissions. These measures begin the process of making actual emissions available to the public, so shippers can make a choice to lower emissions.
One of the ways to reduce emissions is to sail more slowly, or slow steam. Gary Howard’s article quotes MSC, the large container line, that the new CII will cause a 7% to 10% loss of capacity due to slower steaming.
It’s an interesting number. It forces shippers to accept longer voyages before getting cargoes, a clear tradeoff between emissions and prompter delivery. For many customers this will not be an issue; they can alter resupply schedules if the reliability of getting it at the predicted time is high. However, reliability of shipments is another serious problem for container carriers— it’s down around 40% for most carriers. Most of the delay of recent shipments is due to blanked sailings, and to congestion loading and unloading in some major ports. Blanked sailings don’t affect the CII for ships. But congestion delays at ports cause fuel to be burned and push the CII up even if the ships don’t move many miles. the fuel is still used.
I think introducing the CII is a very good idea. True, it could be improved; but we have to start somewhere.
Gary Howard | Nov 01, 2022
MSC: CII to soak up 7-10% of container fleet
Supply Chain and Logistics 