For instructors discussing the likely impacts of the emissions reductions commitments agreed to by the Parties to the UNFCCC under the Durban Platform for Enhanced Action (denominated “Intended National Determined Contributions” or “INDCs”), the just-released eight-page Executive Summary of UNEP’s Annual “Emissions Gap Report” would be an excellent reading. Other recent assessments of INDCs include the UNFCCC’s Synthesis Report on the Aggregate Effect of the Intended Nationally Determined Contributions, and studies by Climate Action Tracker and Climate Interactive. The 2015 Report compares projected emission levels in 2030 (based on the INDCs of 114 States by October 1, 2015) with scientific assessments of emissions pathways consistent with keeping temperature increases below 2C from pre-industrial levels.
Among the study’s findings are:
- Based on the IPCC Fifth Assessment Report’s estimate of a remaining cumulative carbon dioxide emissions budget of 1000 GtCO2 (to avoid passing the 2C threshold), net global carbon emissions will have to be reduced to zero between 2060 and 2075;
- To have a greater than 66% chance of avoiding temperature increases above 2C by the end of century the median level of carbon dioxide equivalent emissions in 2030 should be 42 GtCO2e (range of 31-44), 39 GtCO2e to keep temperature increases to 1.5C.
- While the INDCs made by the Parties to the UNFCCC to date constitute “a real increase in the ambition level compared to a projection of current policies, the emissions gap between full implementation of unconditional INDCs and the least-cost emission level for a pathway to remain below 2C are estimated at 14 GtCO2e in 2030 and 7 GtCO2e in 2025. Conditional INDCs could reduce the gap to 5 GtCO2e in 2025 and 12 GtCO2e in 2030. This translates into a temperature increase of 3.5C by 2100 (66% chance)
- The global emissions levels in 2030 consistent with avoiding passing the 2C threshold is 42 GtCO2e in 2030, while project emissions from unconditional INDCs are projected to be 56 GtCO2e in 2030, or 45 GtCO2e when conditional INDCs are taken into account.
- Global greenhouse gas emissions could be reduced by an additional 5-12 GtCO2e below unconditional INDCs through measures such as enhanced energy efficiency, and International Cooperative Initiatives, such as efforts by cities and regions, sector specific initiatives (such as reducing cement-related initiatives), and forest-related initiatives, e.g. REDD+
The electronic version of the report also includes a number of charts and diagrams that would could be used in class lectures, including portrayals of historical GHG emissions and projections until 2050, the emissions gap of INDCs and requisite reductions in emissions to avoid passing critical temperature thresholds, and a map outlining the INDCs of UNFCCC Parties.