The most effective climate policy is a combination of various measures, ranging from taxing carbon emissions above a certain threshold to the establishment of fiscal measures on fossil fuels, research and investment in renewable energies. This is the conclusion of an international study that compared the climate policies of 40 countries over more than 30 years and was published in the journal Climate Policy. Researchers from the University of Barcelona, the Ludwig-Maximilians-Universität München, the University of Lausanne and the University of Oslo participated in the study.
The research team, which included UB Ramón y Cajal researcher Xavier Fernández i Marín, analysed climate policies by country and their effects between 1990 and 2022. Compared to the other countries studied, Spain is well positioned in areas such as R&D investment policies to improve energy efficiency, and also in requiring companies to calculate their greenhouse gas emissions and report them (known as emissions reporting). However, there is considerable room for improvement in reducing emissions from the transport sector, a goal that could be achieved through specific taxes and congestion charges.
Thanks to an innovative statistical method that allows multiple parameters to be modelled simultaneously, researchers have been able to evaluate the effectiveness of 1,737 climate policies. They also ensured that only initiatives with sufficient empirical evidence were included in the model.
The conclusion is that a diverse and comprehensive repertoire of policy instruments is more effective than relying on isolated measures. The best option, therefore, is to implement a range of well-coordinated measures over a long period of time. The article highlights that Sweden and Norway's comprehensive policy packages are highly effective for climate action.
It also indicates that countries such as Australia, Canada and Japan could effectively reduce carbon dioxide emissions by increasing taxes on fossil fuels.
The research identifies certain policies as particularly effective: taxing carbon emissions above a certain volume or providing financial incentives to reduce them, imposing taxes on fossil fuels, conducting scientific research on climate change, and investing in renewable energy.
The study's conclusions are intended to provide practical guidance to policymakers in identifying the most effective instruments in their specific national context. In addition, the new statistical model developed can be applied to other rapidly growing areas of public policy to assess the effectiveness of measures.
Reference article:
Fernández-i-Marín, X., Hinterleitner, M., Knill, C., & Steinebach, Y. (2026). Effective climate policies for 'all seasons': novel evidence from 40 countries. Climate Policy, 1-14. https://doi.org/10.1080/14693062.2025.2598684
