cers

Certified Emission Reductions (CERs) are a type of carbon credit issued under the Clean Development Mechanism (CDM) established by the Kyoto Protocol. Each CER represents one metric ton of carbon dioxide equivalent (CO2e) reduced or avoided through an eligible emission-reduction project located in a developing country. CERs are intended to deliver verifiable climate benefits while supporting sustainable development in host countries.

Issuance and verification involve a multi-step process. A project design is validated by an independent designated operational entity, and monitoring plans are put in place to measure emissions reductions. Emissions reductions are then verified by independent auditors and submitted for registration with the CDM Executive Board. Once approved, CERs are issued and tracked in a CDM registry, with credits typically retired or purchased by buyers to offset their own emissions.

CERs have been used by governments and businesses to meet compliance targets in various markets, most notably within the European Union Emissions Trading System (EU ETS) before EU rules narrowed the use of credits from CDM projects. In recent years, the prominence of CERs has declined as markets shift toward credits generated under the Paris Agreement framework (ITMOs) and through post-2020 policy adjustments. CERs continue to trade in some markets and in voluntary carbon markets, and many CDM projects remain active in issuing credits for existing agreements.

Criticisms of CERs concern environmental integrity, project additionality, baseline setting, and the risk of double counting. Proponents argue that well-managed CDM projects can deliver sustainable development benefits in host countries, alongside measurable emissions reductions.