This report is a synthesis of the research and re-evaluates the options previously considered in this project (Vieweg et al (2014)) in the light of the negotiation process up to today. The mitigation-related design elements considered are:

• Participation and differentiation of countries;
• Types of commitments, including also the compulsory character of the commitments and time aspects;
• Guidance on ambition of the commitments to assure adequacy of global and individual coun-tries’ efforts;
• Transparency of commitments