Section I. State of Scientific Knowledge in Climate Change. Section II. From Scientific Results to the Political Agenda. Section III. Political and Economical Instruments - An Overview. Introduction. Voluntary Approaches. Taxes. Joint Implementation. Section IV. Tradeable Emission Permits. A Practicable Example: Tradeable Emission Permits for SO2. Design of a CO2 Emission System. Perspective of a CO2 Emission System. Emission Quota Trade - A Simulation Experiment. Section V. Comparison of Instruments and Summary.