Considering the costs and risks of inaction, ambitious action to reduce greenhouse gas emissions is economically rational. However, success in abating world emissions will ultimately require a least-cost set of policy instruments that is applied as widely as possible across all emission sources...

This paper examines the cost of a range of national, regional and global mitigation policies and the corresponding incentives for countries to participate in ambitious international mitigation actions. The paper illustrates the scope for available instruments to strengthen these incentives and...