Taking stock of national climate policies to evaluate implementation of the Paris Agreement

TLDR

Many countries have adopted national climate policies to meet their Nationally Determined Contributions and support the Paris Agreement temperature goals. The study aims to systematically evaluate how effective current national policies are in achieving global temperature targets. The authors use a public policy database and a multi‑model scenario analysis to assess the combined effort of countries during the 2023 global stocktake. Multi‑model analysis shows that current national policies leave a 22.4–28.2 GtCO₂eq emission gap by 2030, which would shrink by a third if NDCs were fully implemented, yet many countries still fall short of pledged contributions and optimal 2 °C pathways, indicating a need for accelerated renewable policy implementation and efficiency gains, while the policies already reduce emissions by 3.5 GtCO₂eq relative to a no‑policy baseline.

Abstract

Many countries have implemented national climate policies to accomplish pledged Nationally Determined Contributions and to contribute to the temperature objectives of the Paris Agreement on climate change. In 2023, the global stocktake will assess the combined effort of countries. Here, based on a public policy database and a multi-model scenario analysis, we show that implementation of current policies leaves a median emission gap of 22.4 to 28.2 GtCO2eq by 2030 with the optimal pathways to implement the well below 2 °C and 1.5 °C Paris goals. If Nationally Determined Contributions would be fully implemented, this gap would be reduced by a third. Interestingly, the countries evaluated were found to not achieve their pledged contributions with implemented policies (implementation gap), or to have an ambition gap with optimal pathways towards well below 2 °C. This shows that all countries would need to accelerate the implementation of policies for renewable technologies, while efficiency improvements are especially important in emerging countries and fossil-fuel-dependent countries. To evaluate the effectiveness of current national policies in achieving global temperature targets is important but a systematic multi-model evaluation is still lacking. Here the authors identified a reduction of 3.5 GtCO2 eq of current national policies relative to a baseline scenario without climate policies by 2030 due to the increasing low carbon share of final energy and the improving final energy intensity.