The classification society, Germanischer Lloyd (GL), has launched a prototype CO2-index, based on MEPC/Circ.471, which is available for all GL classed ships within “fleet online”. On the basis of installed power, consumed fuel and transported cargo, CO2 emissions can be determined. Computed index values can be compared to other ships’ indices and eventually be used to minimize emissions from transport.
The new CO2-index tool by GL can be used to record fuel consumption, transported cargo and distance between two consecutive ports. With carbon emission factors specified by IMO, the CO2-index is calculated for each voyage and later averaged for a still to be defined period (a year might be practical). At the end of the period, a GL surveyor will check the recorded data and eventually issues – on behalf of a flag state – a certified CO2-index which is then valid for the next period. If data for more than one vessel is entered – visible for the owner and manager of a particular vessel or fleet - a comparison of CO2-indices across a fleet is possible. This function in particular is expected to trigger a learning effect as differences in fuel consumption will be made explicit and more transparent with the data associated to each vessel and voyage segment.
In 2003, the United Nations Framework Convention on Climate Change (UNFCCC) tasked IMO to initiate developments related to the reduction of green house gas emissions from ships. The assembly of MEPC adopted this in a resolution. The future standards for the assessment of a ship’s CO2-emissions could be established by IMO by amending the existing guideline. The responsibility for the certification and regular update of a CO2-index of the ships would be with the flag state of the vessel.