A study by CE Delft, titled ‘Comparison of CO2 emissions of MARPOL Annex VI compliance options in 2020’, has found that CO2-emissions associated using Exhaust Gas Cleaning Systems vary between 1.5% and 3% for a number of representative ships. In many cases, the emissions caused by producing low-sulphur fuels for these ships are higher, depending on the quality of the low-sulphur fuel, the refinery and the crude oil slate.