Combining climate measures key to cutting emissions: study

Success stories include the UK’s 2013 introduction of a carbon price, renewable energy subsidies and a coal phase-out plan – Copyright AFP JUSTIN TALLIS

A major new study on the effectiveness of climate protection measures, such as taxes and subsidies, in reducing greenhouse gases was published Thursday, finding that stand-alone action does not produce much effect.

The study, published in the journal Science, analysed 25 years of public policies in 41 countries on six continents.

The report found that of 1,500 policies analysed in sectors such as energy, transport and buildings, “only 63 effective climate policies were identified, each leading to an average emission reduction of 19 per cent”.

“Scientists show that bans on coal-fired power plants or combustion engine cars do not result in significant emission reductions when implemented in isolation,” said the Potsdam Institute for Climate Impact Research (PIK), which led the study together with the Mercator Research Institute for the Global Common Goods and Climate Change (MCC).

“Successful cases only occur when combined with tax or pricing incentives as part of a well-designed policy, as happened in the UK with coal-fired power plants or in Norway with cars,” the researchers say.

The study uses a new OECD database and an innovative approach combining machine learning methods with proven statistical analyses.

“63 effective policy interventions were identified, leading to total emissions reductions of 0.6–1.8 billion tonnes of CO2.”

By comparison, the United Nations estimates that in 2022, humanity will have emitted 57.4 billion tonnes of CO2 equivalent.

Successes included the introduction of a minimum carbon price in the UK in 2013, renewable energy subsidies and a coal phase-out plan.

The scientists hope their work will influence the climate action plans that countries will update and must submit to the UN by February 2025.

The aim of these roadmaps is to maintain the central goal of the Paris Agreement of limiting warming to 1.5 degrees Celsius above pre-industrial levels.

– “The right mix is ​​key” –

The interactive Climate Policy Explorer website provides an overview of the results, analyses and methods and is available to the general public.

“Our findings show that more policies do not necessarily mean better results. Instead, the right mix of measures is key,” explained lead study author Nicolas Koch from PIK and MCC.

“For example, subsidies and regulations alone are not enough; only when combined with price-based instruments, such as carbon and energy taxes, can they deliver significant emission reductions.”

“But by focusing only on 69 statistically identifiable large trend changes, they miss the impact of thousands of smaller efforts around the world and the cumulative and often self-reinforcing impact of many smaller actions,” said Michael Grubb of University College London.

He also admitted that it is “the most advanced study to date.”

“Their conclusion that a combination of policies is needed to achieve large effects makes perfect sense,” he added.

“The study focuses only on policies that introduce sudden reductions, whereas most climate policies focus on the efficiency of new things or the long-term trajectory of emissions, and it takes many years to create greener infrastructure or ways of living,” said Robin Lamboll of Imperial College London.