Do decarbonization policies work? Evidence from a global meta-analysis

Despite the increasing number of net-zero commitments worldwide, a significant gap remains between climate targets and their real-world implementation effects. This study conducts a systematic meta-analysis of 99 empirical studies, integrating more than 1000 standardized effect sizes across 37 decarbonization policy instruments worldwide. The results show that the distribution of samples across regions is highly uneven, with studies from the European Union (EU), the United States (US), Canada, and China accounting for most of the evidence base. We observe that market-based instruments, particularly carbon pricing and taxation measures, as well as several emissions trading systems (ETS) (e.g., the UK's carbon price support, Canada's ETS, the US cap-and-trade, and China's ETS), exhibit statistically significant emission reduction effects. Through multi-model comparisons, our analysis reveals that the average abatement effect of policies ranges between national emissions reductions of 10.5% and 12.6%. However, policies such as net energy metering, emissions performance standards, and the Swiss ETS show counterproductive mitigation effects, e.g. increases in emissions. Our interaction analysis shows that policy effectiveness depends highly on how well a given instrument aligns with sectoral characteristics. Energy efficiency policies perform well when applied within a single sector but perform very differently when used across sectors. Market-based mechanisms also display clear sectoral selectivity in their performance. This study not only reveals the variation in mitigation outcomes across policy instruments and sectors but also provides empirical evidence on how institutional conditions shape policy performance. The findings offer practical insights for building more effective, inclusive, and sustainable pathways toward decarbonization.