Currently, international climate negotiations concentrate on design issues for the flexible instruments outlined in the Kyoto Protocol. As the 6th Conference of the Parties to the U.N. Framework Convention on Climate Change in late 2000 or early 2001 has to take decisions on these matters, it is imperative to develop solutions that combine long-term economic efficiency with long-term environmental effectiveness. Sometimes, a reconciliation of these targets is difficult and compromises have to be made. This report discusses solutions for three critical issues which have got different degrees of attention until now but are linked inasmuch their solution will be crucial for the success of the Kyoto Protocol. The authors have come across them d...