Insights on different participation schemes to meet climate goals

Models and scenarios to assess greenhouse gas mitigation action have become more diversified and detailed, allowing the simulation of more realistic global climate policy set-ups. In this paper, different participation schemes to meet different levels of radiative forcing are analysed. The focus is on scenarios that are in line with the 2 °C target. Typical stylised participation schemes are based either on a perfect global carbon market or delayed participation with targets only for developed countries, no actions by developing countries and no access to credits from offsetting mechanisms in developing countries. This paper adds an intermediate policy scenario assuming a gradual incorporation of all countries, including a gradually developing carbon market, and taking into account the ability to contribute of different parties. Perfect participation by all parties would be optimal, but it is shown that participation schemes involving a gradual and differentiated participation by all parties can substantially decrease global costs and still meet the 2 °C target. Carbon markets can compensate in part for those costs incurred by developing countries' own, autonomous mitigation actions that do not generate tradable emission credits.