As global temperatures and greenhouse gas emissions break records, the latest Emissions Gap Report from the UN Environment Programme (UNEP) finds that current pledges under the Paris Agreement put the world on track for a 2.5-2.9°C temperature rise above pre-industrial levels this century, pointing to the urgent need for increased climate action. Maintaining the possibility of achieving the Paris Agreement temperature goals hinges on significantly strengthening mitigation this decade to narrow the emissions gap. This will facilitate more ambitious targets for 2035 in the next round of Nationally Determined Contributions (NDCs) and increase the chances of meeting net-zero pledges, which now cover around 80 per cent of global emissions. These are some of the main conclusions from the 2023 Emissions Gap Report by the United Nations Environment Programme (UNEP), to which PBL Netherlands Environmental Assessment Agency contributed.
Nations must go further than current Paris pledges or face global warming of 2.5-2.9oC
If mitigation efforts implied by current policies are continued at today’s levels, global warming will only be limited to 3°C above pre-industrial levels in this century. Fully implementing efforts implied by unconditional Nationally Determined Contributions (NDCs) would put the world on track for limiting temperature rise to 2.9°C. Conditional NDCs fully implemented would lead to temperatures not exceeding 2.5°C above pre-industrial levels. All of these are with a 66 per cent chance. These temperature projections are slightly higher than in the 2022 Emissions Gap Report, as the 2023 report includes a larger number of models in the estimation of global warming.
Current unconditional NDCs imply that additional emissions cuts of 14 GtCO2e are needed in 2030 over predicted levels for 2°C. Cuts of 22 GtCO2e are needed for 1.5°C. The implementation of conditional NDCs reduces both these estimates by 3 GtCO2e. In percentage terms, the world needs to cut 2030 emissions by 28 per cent to get on track to achieve the 2°C goal of the Paris Agreement, with a 66 per cent chance, and 42 per cent for the 1.5°C goal.
If all conditional NDCs and long-term net-zero pledges were met, limiting the temperature rise to 2°C would be possible. However, net-zero pledges are not currently considered credible: none of the G20 countries are reducing emissions at a pace consistent with their net-zero targets. Even in the most optimistic scenario, the likelihood of limiting warming to 1.5°C is only 14 per cent.
Some progress, but not enough
Policy progress since the Paris Agreement was signed in 2015 has reduced the implementation gap, defined as the difference between projected emissions under current policies and full NDC implementation. GHG emissions in 2030 based on policies in place were projected to increase by 16 per cent at the time of the adoption of the Paris Agreement. Today, the projected increase is 3 per cent.