Certified Emission Reductions (CERs) are credits for emission reductions achieved with projects resulting from the Clean Development Mechanism (CDM). CDM is an arrangement under the Kyoto Protocol which allows industrialized countries with a greenhouse gas reduction commitment (called Annex 1 countries) to invest in projects that reduce greenhouse gas emissions in developing countries.
This is a lower cost alternative to undertaking more expensive emission reduction projects in their own countries. It is therefore important that the project undertaken establishes that it would not have occurred without the additional incentive provided by carbon credit revenue – otherwise there would be a net increase in global emissions.
CDM is supervised by the CDM Executive Board (CDM EB) and is under the guidance of the Conference of the Parties (COP/MOP) of the United Nations Framework Convention on Climate Change (UNFCCC). One CER signifies an emission reduction of one tonne of CO2 equivalent.