This article compares two carbon governance instruments – the Clean Development Mechanism (CDM) and Reducing Emissions from Deforestation and Degradation (REDD+) – to assess lessons from the former for the latter regarding effectiveness and legitimacy of such instruments. The article argues that the CDM has a relatively high degree of output-oriented legitimacy resulting in effectiveness and some input-oriented legitimacy, with few discernible tradeoffs between them. In contrasting this to REDD+, the hypotheses are advanced that (i) output-oriented legitimacy/effectiveness can again be achieved but that (ii) a higher degree of input-oriented legitimacy is necessary for REDD+ and thus also a certain trade-off between the two forms of legitimacy can be expected. This is shown through comparing the technologies and methodologies, economic rationales, political support, regulatory structures, and environmental impacts of both instruments.

Research Highlights

  • The history of the CDM provides valuable lessons for REDD+.
  • Carbon governance rests on output- as well as input-oriented legitimacy.
  • The CDM has a relatively high degree of perceived output-legitimacy.
  • REDD+ will also be effective but will depend on more input-legitimacy.


Reducing Emissions from Deforestation and Degradation (REDD+); Clean Development Mechanism (CDM); Effectiveness; Legitimacy