There are few rigorous impact evaluations of climate change interventions. But some examples in the field of conservation stand out. A number of recent studies evaluate the impact of protected areas, payment for environmental services and decentralized forest management. Climate change interventions have much to learn from experiences in such fields. Despite the limited experience so far in the area, there are many opportunities to conduct impact evaluation of climate change.

Thia briefing argues that impact evaluations need to be integrated into mitigation interventions from the outset. Each policy instrument should be evaluated in detail across different sectors to build up an evidence base for comparison with other policy instruments and national contexts need to be accounted for. In addition, there is a need to calculate the cost-effectiveness of the reduction of emissions resulting from different interventions. This requires identifying a value to all the costs and benefits resulting from the interventions. If the impact of the project on carbon emissions is known, it is quite straightforward to calculate the cost per ton of avoided emission. Interventions can have both positive and negative development impacts, and this should be taken into account in the cost-benefit analysis of climate change interventions.