Also in this chapter:


Annex I Target For the purpose of this report, the quantified economy-wide emission reduction targets submitted by UNFCCC Annex I countries to the Copenhagen Accord’s Appendix I.
Conditional pledge Pledges made by some countries that are contingent on the ability of national legislatures to enact the necessary laws, ambitious action from other countries, realization of finance and technical support, or other factors.
Copenhagen Accord The 15th Conference of the Parties to the UNFCCC took note of this agreement in Copenhagen, Denmark in December 2009. The Accord includes two appendices listing Annex I and non-Annex I pledges, which are analyzed in this report.
Cumulative Emissions Sum of annual global greenhouse gas emissions over a period of time. Because many greenhouse gases persist in the atmosphere for a long time, cumulative emissions greatly influence concentrations and therefore temperature.
Double Counting In the context of this report, double counting refers to a situation in which the same emission reductions are counted towards meeting two countries’ pledges.
Emissions Pathway The trajectory of annual global greenhouse gas emissions over time.
Energy and Industry CO2 Emissions CO2 emissions from the energy and industry sectors. These are often referred to in this report when describing emission reduction rates and negative emissions
Feasible Rates of Emission Reduction The average annual rate of emission reductions assumed feasible given assumptions about technology development, economic costs, and/or sociopolitical factors.
Global (total) Greenhouse Gas Emissions Emissions from all sectors and all greenhouse gases
Integrated Assessment Models Models of climate change that seek to combine knowledge from multiple disciplines in formal integrated representations. As such they describe the full chain of climate change, including relevant linkages and feedbacks between socio-economic and biophysical processes.
Likely Chance A greater than 66 per cent likelihood. Used to convey the probabilities of meeting temperature limits.
Lenient LULUCF Credits Credits given for carbon removals from existing forests or other sinks that would have occurred without policy intervention.
Lenient Rules Pledge cases with maximum Annex I “lenient LULUCF credits” and surplus emissions units.
Medium Chance A 50 to 66 per cent likelihood. Used to convey the probabilities of meeting temperature limits.
Negative Emissions Either globally or for a particular sector, the emissions that could occur if, in a given period, the removal of greenhouse gases from the atmosphere as a result of anthropogenic activities is greater than the addition of anthropogenic emissions into it.. Note that in this report negative energy and industry CO2 emissions are often mentioned.
Non-Annex I Action For the purpose of this report, those emission reduction actions submitted to the UNFCCC by non-Annex I countries and listed in the Copenhagen Accord’s Appendix II.
Offsets A general term referring to credits that their use offsets the need to reduce emissions elsewhere.
Overshoot Pathway An emissions pathway wherein the temperature limit will be exceeded for a period of time but will eventually be met.
Pledge For the purpose of this report, pledges include Annex I targets and non-Annex I actions as included in Appendix I and Appendix II, respectively, to the Copenhagen Accord.
Scenario A description of how the future may unfold based on 'if-then' propositions. A scenario in the context of this report consists typically of a representation of an initial socio-economic situation and a description of the key driving forces and future changes in emissions, temperature or other climate change-related variables.
Strict Rules Pledge cases in which the impact of “lenient LULUCF credits” (see definition above) and surplus emissions units are set to zero.
Stylized Pathways These are results from carbon cycle and climate models that are designed to better understand the relationships between emissions and temperatures, but do not explicitly incorporate assumptions about technological, economic or socio-political feasibility of emission reductions.
Surplus Emission Units After the first commitment period of the Kyoto Protocol (2008-2012), according to Article 3, paragraph 13, Parties holding emission units not required for compliance with their commitments are able to carry over these units for future use or sale. These are called “surplus emission units”. There is also the possibility that new surplus emission units will be created in the second commitment period, when targets are set below business-as-usual expectations.
Temperature Limits Targets for maximum global average temperature increases above pre-industrial levels.
20th-80th percentile range Results that fall within the 20-80 per cent range of the frequency distribution of results in this assessment.
Unconditional pledge Pledges made by countries without conditions attached.