Climate policies that achieved major emission reductions: Global evidence from two decades

Meeting the Paris Agreement’s climate targets necessitates better knowledge about which climate policies work in reducing emissions at the necessary scale. Here, we provide the first global, systematic ex-post evaluation identifying policy combinations that have led to large emission reductions out
of 1,500 climate policies implemented between 1998 and 2022 across 41 countries from six continents. Our approach integrates a novel climate policy database that is the most comprehensive, internationally harmonized, policy inventory to-date, with a rigorous, machine learning-based extension of the common difference-in-differences approach. We identify 63 successful policy interventions with total emission reductions between 0.6 and 1.8 Gt CO2. Our insights on effective but rarely studied policies and previously unknown effective combinations of policies highlight the important role of price-based instruments in well-designed policy mixes, and the policy efforts necessary for closing the emissions gap in the building, electricity, industry, and transport sectors.