Using the Clean Development Mechanism for nationally determined contributions and international aviation

The report finds that recognizing all types of CERs for use after 2020 is unlikely to trigger significant additional emission reductions because most available supply comes from projects that would continue abatement without CER revenues. It identifies critical risks to environmental integrity, including double claiming with 2020 targets and the potential for higher cumulative emissions when using CERs for single-year targets. To safeguard environmental integrity, the authors recommend limiting eligibility to newly developed additional projects or already implemented projects at high risk of discontinuing abatement, while ensuring robust accounting through corresponding adjustments.

• The total potential CER supply from registered and non-registered projects in the pipeline for the period 2013 to 2020 is estimated at approximately 5.7 billion CERs, with 4.7 billion coming from registered projects and 1.0 billion from non-registered projects.
• The potential demand for CERs from 2013 to 2020 is estimated at 660 million, leaving roughly 5.0 billion CERs available for use after 2020, which significantly exceeds the estimated CORSIA demand of 2.7 billion for the 2020-2035 period.
• Policies that recognize all types of CERs after 2020 are unlikely to trigger significant new emission reductions because most supply (82% of registered projects) comes from project types with low vulnerability to discontinuing abatement, such as wind and hydropower.
• There is a material risk of double claiming because approximately 77% of the CER supply potential originates from emission sources covered by 2020 targets, and current reporting frameworks (such as Biennial Update Reports) do not effectively account for CERs claimed by other countries.
• Using CERs towards single-year targets (e.g., a 2030 NDC target) poses a higher risk to environmental integrity than using them for multi-year trajectories, as it may enable a higher emissions path in the years leading up to the target year, increasing aggregated cumulative emissions.
• To ensure environmental integrity, the report recommends that policy-makers prioritize CERs from projects newly developed in response to the policy (using the 'start date of the project' as the most suitable milestone) or from already implemented projects at high risk of discontinuing abatement.
• Robust accounting to avoid double claiming could be achieved by limiting eligibility to CERs not covered by 2020 targets or by requiring host countries to apply 'corresponding adjustments' to their reported emissions.

APA

Schneider, L., & Theuer, S. L. H. (2017). Using the Clean Development Mechanism for nationally determined contributions and international aviation. Stockholm Environment Institute. https://www.sei.org/mediamanager/documents/SEI-PR-2017-Using-the-Clean-Development-Mechanism.pdf

Chicago

Schneider, Lambert, and Stephanie La Hoz Theuer. Using the Clean Development Mechanism for nationally determined contributions and international aviation. Stockholm Environment Institute, 2017. https://www.sei.org/mediamanager/documents/SEI-PR-2017-Using-the-Clean-Development-Mechanism.pdf.

Wikipedia

{{cite report |last1=Schneider |first1=Lambert |last2=Theuer |first2=Stephanie La Hoz |title=Using the Clean Development Mechanism for nationally determined contributions and international aviation |publisher=Stockholm Environment Institute |date=2017 |url=https://www.sei.org/mediamanager/documents/SEI-PR-2017-Using-the-Clean-Development-Mechanism.pdf |access-date=23 October 2026 |via=Climate Insights Directory}}

BibTeX

@techreport{schneider2017using, author = {Schneider, Lambert and Theuer, Stephanie La Hoz}, title = {{Using the Clean Development Mechanism for nationally determined contributions and international aviation}}, institution = {Stockholm Environment Institute}, year = {2017}, url = {https://www.sei.org/mediamanager/documents/SEI-PR-2017-Using-the-Clean-Development-Mechanism.pdf}, urldate = {2026-10-23}, note = {Indexed by Climate Insights Directory} }