Climate policy success cases reveal right steps crucial for emissions cut

Merely a higher number of climate policies aimed at reducing emissions do not lead to better outcomes, instead, the right mix of measures is crucial, according to researchers who analysed 1,500 policy interventions implemented between 1998 and 2022.

In their study, published in the journal Science, the authors described 63 success cases, which involved "rarely studied policies and unappreciated policy combinations".

"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 emission reductions," lead author Nicolas Koch from the Potsdam Institute for Climate Impact Research (PIK), Germany, said.

 

The climate policies that the researchers studied covered wide-ranging aspects, from energy-related building codes to purchase subsidies for climate-friendly products and carbon taxes.

The team used a new Organisation for Economic Co-operation and Development (OECD) database, representing the most comprehensive one for climate policies worldwide to date, to identify the measures that achieved large-scale reductions in emissions.

"We systematically evaluated policy measures that have rarely been studied until now, providing new insights into well-designed combinations of complementary policy instruments.

"From this, we derive best practices -- for the building, electricity, industry and transport sectors, and in both industrialised countries and often neglected developing countries," Koch said.

In the industrial sector, for example, China's emissions trading systems significantly reduced emissions after a few years, supported by reduced fossil fuel subsidies and stronger financing incentives for energy efficiency, the authors said.

In the electricity sector, the UK achieved major emissions reductions through a minimum carbon price, subsidies for renewable energy, and a coal phase-out plan, they said.

The researchers also found that through a mix of tax incentives and subsidies for low-emitting vehicles and CO2 efficiency standards, the US was an example of significant emission reductions in the transportation sector, while Germany was another, employing eco-tax reform and truck tolls.

In a policy mix, while it remains challenging to precisely separate the effects of each individual measure, "our 63 success cases provide systematic insights into effective policy combinations, and show how well-designed policy mixes depend on sectors and the development level of countries," lead author Annika Stechemesser from the PIK said.

The findings are vital for supporting policymakers and society in the transition to climate neutrality, Stechemesser said.

As much of the debate around cutting greenhouse gas emissions revolves around which climate policies work, the researchers said that previous studies have focused on a limited range of headline policies, neglecting hundreds of other measures.

This study aimed to fill the gap, the authors said. They have made their results, analysis and methods available to the public through an interactive website, the 'Climate Policy Explorer'.