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Impact of the Doha outcome on surplus emission allowances and their effect on developed country emissions


The outcome from the December 2012 climate negotiations in Doha has clarified the rules regarding surplus units for the Kyoto Protocol. We summarize these new rules and estimate the resulting effective emissions during the second commitment period using our unit trade model. Other options to deal with surplus emission allowances are employed as benchmarks to assess the Doha outcome. The effective emissions for developed countries as a group under the Doha outcome could be 10–11 % below 1990 levels or 4–5 % points below business-as-usual levels for the second commitment period if we assume that non-Kyoto Protocol countries domestically achieve their targets. However, if mechanisms exist where non-Kyoto Protocol countries can trade units, their emissions could increase and effective emissions for developed countries could be 7–8 % below 1990 levels. In this low-ambition situation we find the main impact of the Doha surplus rules to be the introduction of the historical cap on emissions allowances. Without the effect of the cap, the Doha outcome allows the Parties to the second commitment period to emit at business-as-usual levels until 2020, while still leaving surplus units at the end of the second commitment period.

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  1. ERUs are not additional to AAUs or RMUs, but are converted from existing AAUs or RMUs from the host country.

  2. Initial assigned amount is the level of assigned amount units a country is issued at the start of a commitment period, as defined in Article 3, paragraphs 7 bis, 8 and 8 bis, of the Kyoto Protocol.

  3. The EU’s declaration only applies to the CP2 QELRC submitted in Doha. For higher ambition, they will use surplus.

  4. NF3 is included in Annex A of the Kyoto Protocol since the Doha conference in 2012 but is not included in our calculations because of lack of data.


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We acknowledge and appreciate funding by the Federal Ministry for the Environment, Nature Conservation and Nuclear Safety (11_II_093_Global_A_SIDS_and_LDCs), and by the European Climate Foundation for the Climate Action Tracker.

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Correspondence to Claudine M. Chen.

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Chen, C.M., Gütschow, J., Vieweg, M. et al. Impact of the Doha outcome on surplus emission allowances and their effect on developed country emissions. Climatic Change 120, 845–857 (2013).

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  • Emission Trading Scheme
  • Emission Allowance
  • Effective Emission
  • Commitment Period
  • Trade Group