The EU strategy to reduce atmospheric emissions from seagoing ships specifies that policies could be introduced to reduce the climate impacts of shipping. This report designs and evaluates seven possible policies:1 Voluntary commitments2 Requirement for all EU-based ship operators and/or EU-flagged ships to use the IMO CO2 index and report results annually to Member State Administrations and/or the European Commission3 Requirement for EU-based ship operators and/or EU-flagged ships and/or EU-based shippers to meet a unitary CO2 index limit or target4 Future inclusion of refrigerant gases from shipping in the EU regulation and/or an indexing system parallel to the CO2 index5 Inclusion of a mandatory CO2 element in an EU-wide regime for port infrastructure charging6 Inclusion of CO2 emission from shipping in the EU ETS7 Allocation of ship emissions to Member States.All policy options are assessed on four main criteria:1 Operational effectiveness.2 Legal implications.3 Feasibility of monitoring and enforcement.4 Feasibility of implementation.The assessment shows that the most promising option is the inclusion of CO2emissions from shipping in ETS. Under this policy, ship operators would haveto surrender EU allowances for CO2 emissions on their voyage to EU ports. Thispolicy would have a large environmental effectiveness, would be feasible toenforce and feasible to implement, provided that a number of design issues canbe solved. The legal basis for implementation would also require further study.Two other options have an equally large environmental effectiveness. Both arequirement to meet a unitary CO2 index value and a differentiation ofharbour dues could be effective ways to address the climate impact of shipping.However, it is not clear at this stage that a limit value of the CO2 index can beassigned to vessels that would present an incentive to all vessels to reduceemissions, and would do so in all phases of the business cycle. Likewise, it is notclear at this stage that a basis for differentiation of harbour dues can be foundthat would not distort the competitive market between ports and would incentivisevessels to reduce emissions.Three options have limited environmental effectiveness, but are stillrecommended to implement. The inclusion of refrigerant gases in EUregulation would open up very cost effective options to reduce emissions. Theallocation of ship emissions to Member States, if agreed upon in theUNFCCC, would pave the way for a global solution to reduce the climate impacts of shipping. And a requirement to report the IMO CO2 index would provide data that could be used to assess the effectiveness of various policy options, while imposing only a small burden on ship operators.