UNEP Emissions Gap report 2023

Nations must go further than current Paris pledges or face global warming of 2.5-2.9^oC

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% 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% to get on track to achieve the 2°C goal of the Paris Agreement, with a 66% chance, and 42% 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%.

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% at the time of the adoption of the Paris Agreement. Today, the projected increase is 3%.