Scientists have debated for decades whether economies can continue to grow without increasing greenhouse gas emissions. A new study by a Penn State researcher found this may be possible, but only under strict conditions and mostly for the world's wealthiest nations.
The study, published in the journal Social Forces, includes the analysis of more than three decades of data from nations using the international Organisation for Economic Co-operation and Development's Climate Actions and Policies Measurement Framework (CAPMF) database, which does not include the United States, to examine how climate policies affect the link between economic growth and greenhouse gas emissions.
The researchers found that high-income countries were able to reduce or neutralize emissions when they implemented strong climate policies - which can include instruments such as carbon taxes, subsidies for carbon free technologies, bans and technological standards - even as their economies grew.
However, they also found that stricter climate policies were often associated with higher emissions, not lower ones, in lower- and middle-income nations.
Ryan Thombs, assistant professor of rural sociology and co-author of the study, said the findings still suggest that stringent climate policies are important and can benefit sustainability efforts.
"Governments should implement more stringent policies than what are currently in place - our study shows that while their effectiveness can be context specific, even the current most stringent policy is not stringent enough," he said. "We found strategies that maximize human and environmental well-being but don't rely on economic growth are the most effective strategies to mitigate emissions, and they do so in the most equitable manner across different types of countries."
A large and growing body of research has found positive associations between nations' greenhouse gas emissions and economic growth - meaning as economies grow, so do emissions, according to the researchers. The question now is whether economic growth's harmful effect on the environment can be lessened.
"Some argue that growth cannot be decoupled from emissions because it requires ever increasing amounts of natural resources while others argue that it can be decoupled through technological advancements," Thombs said. "What they agree on is that if we want to move to a more sustainable economy, then we need more stringent policies to usher in this transition."
However, he added, few studies have examined the effect of these climate policies on the relationship between economic growth and emissions. Thombs and his co-author - Andrew Jorgenson, professor at the University of British Columbia - aimed to close this gap.
For the study, the researchers analyzed information from 49 countries, including those responsible for the majority of carbon emissions and those that have enacted the most stringent climate policies, from the CAPMF dataset.
"Wealthier countries make up the largest segment of countries in the dataset, but they are also the largest polluters and are mainly where more stringent climate policy is implemented," Thombs said. "Stringency in this database measures the degree by which these policies incentivize or facilitate emission reductions. So, as an example, if two countries have a carbon tax, the country who has a higher tax is considered to have a more stringent policy."
The researchers found that in general, strong climate policy stringency was able to decouple economic growth from emissions. More stringent climate policy was associated with relative or absolute decoupling in 32 countries.
However, they also found more stringent climate policy was associated with a stronger association between economic growth and emissions in 12 countries and it had no impact in five countries.
"Greater policy stringency was actually associated with increases in emissions in lower-income and middle-income nations, suggesting the effect of policy varies depending on the context," Thombs said.
The researchers also ran several hypothetical scenarios through a model they developed that included a lower-income, middle-income and higher-income nation. They found that in these scenarios, steady-state and degrowth scenarios offered the most sustainable futures.
Moving forward, Thombs said the findings suggest a need for additional studies into the different effects they observed across high-income and lower-income countries, as well as into whether certain policies are driving this relationship or if it's a combination of policies.
