We analyze the economic effects of the differentiated targets for carbon abatement in six European Union member states. Our recursively-dynamic model includes a detailed representation of trade and energy consumption and incorporates optimistic projections for future energy markets provided by the European Commission as the Business-as-Usual scenario. In the base case we find that the EU implementation of the Kyoto Protocol implies low overall costs and a relatively even cost distribution across member states. We also show that a less optimistic development in energy efficiency implies higher costs in all countries, especially in those with high abatement costs. Finally, we find that uniform abatement targets increase overall costs marginally but changes the cost distribution significantly, holding total EU emissions constant