Around the world, about 30% of areas have managed to unhook their economic growth from carbon emissions, a new study suggests. The findings highlight the potential for so-called green growth – but also its limits.
In the past, economic growth and carbon emissions have gone hand in hand: as the first increases, so does the other. That pattern will have to change if economies are to continue to prosper while reaching net-zero emissions, so “decoupling” has become an important sustainability benchmark.
In the new study, researchers analyzed 30 years of data on economic growth and carbon emissions for nearly 1,500 regions within countries around the world. Past studies have looked at decoupling mostly at a national scale or in individual cities. But with sub-national governments increasingly implementing climate policies, this approach, at once granular and comprehensive, was overdue, the researchers argue.
Over the past three decades, 30% of the regions have fully decoupled economic growth and carbon emissions, achieving economic expansion with stable or decreasing emissions, the researchers report in the journal Proceedings of the National Academy of Sciences.
“The number of regions achieving absolute decoupling has increased over the past three decades,” adds study team member Maria Zioga, a doctoral researcher at the Potsdam Institute for Climate Impact Research in Germany.
In addition, roughly half of the regions have achieved relative decoupling, meaning that emissions grow more slowly than economic output.
Regions with high incomes, a history of carbon-intensive industry, or strong service and manufacturing sectors are especially likely to have achieved absolute decoupling, the researchers found. “These regions can usually afford to invest in green technologies which are less accessible to lower-income regions/countries,” Zioga says.
Differences in decoupling rates and emissions intensity – which refers to carbon emissions per unit of economic growth – are generally greater within countries than between them.
Decoupling is more likely to be seen in regions that have received financial support for climate action and, in the European Union, in regions where cities have implemented climate change mitigation efforts. These findings highlight the importance of sub-national climate action and analysis, the researchers say.
Still, national action also matters. “Higher national spending as a percentage of GDP directed toward subnational climate action seems to be a key factor in effective decoupling,” Zioga says. “Additionally, regions that have implemented local climate mitigation plans tend to decouple faster at the subnational level, with nationally guided plans proving to be more effective than locally developed ones.”
The researchers also used past decoupling trends to estimate the year in which net-zero emissions are likely to be achieved for each region. Less than half of regions are likely to reach net-zero before 2050, they found. Indeed, the average region is not likely to reach net-zero until sometime between 2104 and 2121.
The study analyzes decoupling with respect to emissions associated with economic production in each region, not consumption. But wealthy regions tend to “outsource” emissions-intensive production of the goods they consume to other, less wealthy areas. “Developing global data on consumption-based emissions at the subnational level is an important avenue for future work,” Zioga says.
Source: Zioga M. et al. “Observed carbon decoupling of subnational production insufficient for net-zero goal by 2050.” Proceedings of the National Academy of Sciences 2024.
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