Combination of climate measures is key to reducing emissions: study August 25, 2024

Among the successes identified is the introduction in Britain in 2013 of a minimum carbon price, subsidies for renewable energy and a plan to phase out coal (JUSTIN TALLIS)

By AFP - Agence France Presse

Combination of climate measures is key to reducing emissions: study.

A major new study published on Thursday on the effectiveness of climate measures, such as taxes or subsidies, in reducing greenhouse gases concluded that isolated measures do not make much difference.

Published in the journal Science, the study examined 25 years of public policies in 41 countries on six continents.

It concluded that of the 1,500 policies analyzed in sectors such as energy, transport and construction, “only 63 cases of successful climate policies were identified, each of which led to average reductions in emissions of 19%”.

“The researchers demonstrate that bans on coal-fired power plants or combustion engine cars do not result in large emissions reductions when implemented in isolation,” said the Potsdam Institute for Climate Impact Research (PIK), which led the study with the Mercator Research Institute on Global Commons and Climate Change (MCC).

“Successful cases only arise in conjunction with tax or price incentives in well-designed policy combinations, as demonstrated 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 analysis.

It “identified 63 successful policy interventions with total emission reductions of between 0.6 billion and 1.8 billion tons of CO2”.

In comparison, humanity emitted 57.4 billion tons of CO2 equivalent in 2022, according to United Nations estimates.

Among the successes identified is the introduction in Britain in 2013 of a minimum carbon price, subsidies for renewable energy and a plan to phase out coal.

The researchers hope that their work will influence the climate roadmaps that countries are updating and must present to the UN by February 2025.

The aim of these roadmaps is to keep alive the Paris Agreement's main goal of limiting warming to 1.5 degrees Celsius above pre-industrial levels.

- The right combination is crucial

An interactive website, “Climate Policy Explorer”, offers an overview of the results, analysis and methods, and is accessible to the public.

“Our findings demonstrate that more policies do not necessarily equate to better results. Instead, the right combination of measures is crucial,” explained the study's lead author, Nicolas Koch of PIK and MCC.

“For example, subsidies or regulations alone are insufficient; only in combination with price-based instruments, such as carbon and energy taxes, can they deliver substantial emissions reductions.”

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

He also acknowledged “the most sophisticated study to date”.

“Its conclusion that large impacts require combinations of policies makes perfect sense,” he added.

“The study only looks for policies that make sudden reductions, whereas most climate policies work on the efficiency of new things or on the long-term trajectory of emissions, taking many years to build greener infrastructure or ways of life,” said Robin Lamboll of Imperial College London.

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