This report by the Energy Transitions Commission (ETC) details pathways to decarbonise the shipping industry by mid-century. Shipping emits 0.9Gt1 of CO2 and accounts for 11 per cent of total annual transport sector emissions (2014 data). However, the report estimates that emissions from business as usual shipping activities could nearly double by 2050. Decarbonising the sector is therefore important to ensure its alignment with the Paris Agreement goals. While higher energy efficiency and a shift to lower-carbon fuels could help achieve zero carbon emissions in shipping, these transformations face some challenges, including the cost, uncertainty about suitable technological options, and the fragmented nature of the industry according to the ETC. This report complements the ETC study 'Mission Possible: Reaching net-zero carbon emissions from harder-to-abate sectors by mid-century' from November 2018.