After the release of a major climate report Last year, UN Secretary-General António Guterres warned that the “climate time bomb” was ticking. Standing behind a podium with the United Nations symbol of a globe surrounded by olive branches, Guterres declared“Our world needs climate action on all fronts – everything, everywhere, all at once.”
That call to action (possibly inspired by the movie with the same name) seems to be a decent summary of what it takes to tackle rising carbon emissions. According to a new study published Thursday in the journal Sciencecountries have succeeded in reducing emissions by putting a price on carbon, but the biggest cuts have come from adopting a combination of policies. Seventy percent of the cases where countries saw big results were linked to multiple actions that generated “synergy.”
“There really isn’t a silver bullet,” said Felix Pretis, a co-author of the study and an economics professor at the University of Victoria in British Columbia, Canada. “It kind of goes against the conventional wisdom that economists say that carbon pricing is the one thing we should be pushing for.”
Pretis and researchers in Germany, France and the United Kingdom looked for big drops in countries’ emissions and compared the results to the policies adopted. Using machine learning, they analyzed 1,500 policies in 41 countries between 1998 and 2022, and found just 63 cases in which countries significantly reduced emissions. In total, these cuts contributed between 600 million and 1.8 billion metric tons of carbon dioxide.
“I feel like there’s so much gloom and doom around climate policy that nothing’s really happening, but actually we’ve made a fair amount of progress,” Pretis said.
Part of the reason the study found only 63 success stories is because it set a high bar in terms of emissions reductions, Pretis said. “But at the same time, we also see that many policies have been implemented that don’t really bite.” Governments are falling short of their climate targets set in the Paris Agreement of 2015 by approx 23 billion metric tons of CO2. The problem is not just caused by a lack of ambition, says the study, but a lack of knowledge in terms of what policies work in practice.
Carbon pricing, whether through a carbon tax or a cap-and-trade program, has been “a notable exception” in that it has sometimes led to large emissions cuts on its own, the study says, and has worked particularly well for emissions from industry and electricity. “However, it works even better if you complement and package it as a policy mix,” Pretis said.
For example, the United Kingdom saw a 19 percent drop in electricity sector emissions between 2012 and 2018 after the European Union introduced a carbon price for power producers. Around the same time, the UK implemented a host of other steps, including stricter air pollution standards, incentives for building solar and wind farmsand a plan to phase out coal plants. Similarly, China reduced its industrial emissions by 20 percent from 2013 to 2019 through a pilot emissions trading program, but also by reducing fossil fuel subsidies and strengthening financing for energy efficiency investments.
To reduce emissions from transport and buildings, the study shows that it is an even better idea to link several tools together. Regulation is the most powerful policy for reducing transport emissions, and it can work well with carbon pricing or subsidies. The study also highlights that different policies can be effective in different contexts. The researchers found that carbon pricing was less effective in developing economies, places where regulations to limit pollution and investments in green technology may be a better fit.
Gernot Wagner, a climate economist at Columbia Business School, said the study shows what measures to limit carbon emissions were politically possible, but it should not necessarily serve as a guide for future policymaking. “It does not capture policies that never succeeded – including those that would have been very successful but failed precisely because they would have been so effective.”
Because of the study’s limits, it also missed some of the most important climate policies, Wagner said, citing the carbon tax Sweden’s government passed in the early 1990s and the Inflation Reduction Act, which was signed into law by President Joe Biden in 2022. is signed. States’ landmark climate legislation invests hundreds of billions of dollars in clean energy and tax credits for low-carbon technologies like heat pumps. The law is estimated to reduce emissions by 40 percent by 2030compared to 2005 levels.
“I wouldn’t be surprised if this exercise is repeated five, 10 years from now, the Inflation Reduction Act will show up” as a big drop in emissions, Wagner said.
