The paper first argues that the Directive for EU-wide greenhouse gas emission trading still carries a number of weaknesses, such as: . still no clear link with other climate policies in the Member States; . the subsidiarity with regard to the allocation of allowances may distort intra-EU competition; . lack of clarity as to what the (future) scope and coverage of the scheme may look like. Then, it is argued that not convincingly linking the scheme to the flexibility instruments of the Kyoto Protocol, JI and CDM, or establishing such a link only later or based on some supplementarity rule, not only carries a number of risks, but may also be circumvented by the Member States using their freedom with regard to their national climate policy design.