The Clean Development Mechanism (CDM) was a United Nations Framework Convention on Climate Change (UNFCCC) scheme set up as a consequence of the 1997 Kyoto Protocol that enabled richer, developed countries to purchase carbon credits representing presumed emissions reductions from developing countries. 

The CDM failed to produce high-quality carbon credits, with the vast majority of emission reductions credited under the CDM unlikely to have resulted in additional reductions. In some cases, the CDM led to countries causing more emissions than would have occurred had countries met their targets through other means.

The countries under the UNFCCC have devised a fresh carbon crediting framework, under Article 6 of the Paris Agreement, which was finalised at COP29 in 2024 and operationalised in 2025.

Even though the  CDM is still running in 2025, at least on paper, it was effectively abandoned years ago and has been replaced by the Paris Agreement Crediting Mechanism, a new carbon market scheme under Article 6.4 of the Paris Agreement. Unfortunately, many CDM units could transition into the Article 6 carbon market, undermining its effectiveness as a climate tool.