A major new study published Thursday on the effectiveness of climate measures such as taxes or subsidies in reducing greenhouse gases has found stand-alone measures fail to make a big difference. Published in the journal Science, the study examined 25 years of public policies in 41 countries across six continents. It concluded that out of the 1,500 policies analysed in sectors including energy, transport and construction, “only 63 cases of successful climate policies, each leading to average emission reductions of 19 percent, were identified.” “The researchers show that bans on coal-fired power plants or combustion engine cars do not result in major emissions reductions when implemented alone,” said the Potsdam Institute for Climate Impact Research (PIK) that led the study with Mercator Research Institute on Global Commons and Climate Change (MCC). “Successful cases only arise in tandem with tax or price incentives in well-designed policy mixes, as shown in the UK for coal-fired power generation or in Norway for cars,” the researchers said. The study used a new OECD database and an innovative approach that combined machine learning methods with established statistical analyses. It “identified 63 successful policy interventions with total emission reductions between 0.6 billion and 1.8 billion tonnes CO2”. By comparison, humanity emitted 57.4 billion tonnes of CO2 equivalent in 2022, according to United Nations estimates.