Single-year mitigation targets: Uncharted territory for emissions trading and unit transfers

The paper argues that single-year targets create uncertainty regarding emissions pathways and may reduce cumulative mitigation outcomes compared to multi-year targets, especially when tradable units are used. It assesses four accounting options to address these issues and recommends that future international agreements require continuous multi-year targets to ensure comparability and alignment with carbon budgets.

• Single-year targets provide less certainty regarding cumulative emissions than multi-year targets, creating a risk that emissions increase during the goal period and are only reduced shortly before the target year.
• The use of transferable units to meet a single-year target can significantly lower ambition, as a country could theoretically meet its target entirely through unit acquisition without implementing any domestic emission reductions.
• Single-year targets are fundamentally incompatible with the functioning of domestic emissions trading schemes (ETS), which rely on multi-year targets to provide temporal flexibility and price signals based on long-term scarcity.
• Issuing and using emission units in years prior to a single-target year can lead to higher cumulative global emissions if those units are used to meet the target rather than to accelerate the reduction path beyond what would have occurred without unit issuance.
• The authors evaluated four accounting options for unit use: restricting units to the target year vintage (Option 1), limiting the fraction of targets met by units (Option 2), requiring translation of single-year targets into multi-year paths (Option 3), and translating only the unit-use portion into a multi-year path (Option 4).

APA

Lazarus, M., Kollmuss, A., & Schneider, L. (2014). Single-year mitigation targets: Uncharted territory for emissions trading and unit transfers. Stockholm Environment Institute. https://www.sei.org/mediamanager/documents/Publications/Climate/SEI-WP-2014-01-Single-year-pledges.pdf

Chicago

Lazarus, Michael, Anja Kollmuss, and Lambert Schneider. Single-year mitigation targets: Uncharted territory for emissions trading and unit transfers. Stockholm Environment Institute, 2014. https://www.sei.org/mediamanager/documents/Publications/Climate/SEI-WP-2014-01-Single-year-pledges.pdf.

Wikipedia

{{cite report |last1=Lazarus |first1=Michael |last2=Kollmuss |first2=Anja |last3=Schneider |first3=Lambert |title=Single-year mitigation targets: Uncharted territory for emissions trading and unit transfers |publisher=Stockholm Environment Institute |date=March 2014 |url=https://www.sei.org/mediamanager/documents/Publications/Climate/SEI-WP-2014-01-Single-year-pledges.pdf |access-date=17 August 2026 |via=Climate Insights Directory}}

BibTeX

@techreport{lazarus2014singleyear, author = {Lazarus, Michael and Kollmuss, Anja and Schneider, Lambert}, title = {{Single-year mitigation targets: Uncharted territory for emissions trading and unit transfers}}, institution = {Stockholm Environment Institute}, year = {2014}, month = mar, url = {https://www.sei.org/mediamanager/documents/Publications/Climate/SEI-WP-2014-01-Single-year-pledges.pdf}, urldate = {2026-08-17}, note = {Indexed by Climate Insights Directory} }