A systematic review and meta-analysis of ex-post evaluations on the effectiveness of carbon pricing reveal that introducing a carbon price leads to statistically significant emissions reductions for at least 17 of 21 carbon pricing schemes, with reductions ranging from -5% to -21% (-4% to -15% after correcting for publication bias). The study highlights critical evidence gaps for many unassessed carbon pricing schemes and the price elasticity of emissions reductions. The findings suggest that carbon pricing is effective in reducing greenhouse gas emissions, with an average reduction of -10.4% across schemes. The study also identifies heterogeneity in the effectiveness of carbon pricing schemes, influenced by policy design, context, and implementation. The results indicate that the effectiveness of carbon pricing is not solely determined by the carbon price level but also by the specific policy design and context. The study emphasizes the need for more rigorous synthesis of carbon pricing and other climate policies to better understand what works and accelerate learning on climate solutions. The study also highlights the importance of addressing publication bias and the quality of primary studies in assessing the effectiveness of carbon pricing. The findings suggest that carbon pricing policies can significantly reduce emissions, but the effectiveness varies across schemes and is influenced by factors such as policy design, context, and implementation. The study provides a comprehensive analysis of the effectiveness of carbon pricing, highlighting the need for further research to address gaps in the evidence base and improve the understanding of carbon pricing's role in climate policy.A systematic review and meta-analysis of ex-post evaluations on the effectiveness of carbon pricing reveal that introducing a carbon price leads to statistically significant emissions reductions for at least 17 of 21 carbon pricing schemes, with reductions ranging from -5% to -21% (-4% to -15% after correcting for publication bias). The study highlights critical evidence gaps for many unassessed carbon pricing schemes and the price elasticity of emissions reductions. The findings suggest that carbon pricing is effective in reducing greenhouse gas emissions, with an average reduction of -10.4% across schemes. The study also identifies heterogeneity in the effectiveness of carbon pricing schemes, influenced by policy design, context, and implementation. The results indicate that the effectiveness of carbon pricing is not solely determined by the carbon price level but also by the specific policy design and context. The study emphasizes the need for more rigorous synthesis of carbon pricing and other climate policies to better understand what works and accelerate learning on climate solutions. The study also highlights the importance of addressing publication bias and the quality of primary studies in assessing the effectiveness of carbon pricing. The findings suggest that carbon pricing policies can significantly reduce emissions, but the effectiveness varies across schemes and is influenced by factors such as policy design, context, and implementation. The study provides a comprehensive analysis of the effectiveness of carbon pricing, highlighting the need for further research to address gaps in the evidence base and improve the understanding of carbon pricing's role in climate policy.