If you follow discussions about climate change, you must have heard of decoupling. The term refers to the possibility of detaching Growth Domestic Product (GDP) from environmental pressures. The green growth everyone talks about these days presumes that economic activities can be decoupled from ecological damage.

Studies on decoupling don’t usually become viral, but one did. In March 2019, Corinne Le Quéré from the Tyndall Centre for Climate Change Research in the UK and nine other scholars published an article in Nature titled “Drivers of declining CO2 emissions in 18 developed economies.”

This is one among many – 835 to be precise – according to an exhaustive review of the literature. What makes this study special is how often it has been cited online to acclaim green growth. A careful reading of the article, however, gives a more nuanced impression.

The decoupling rates are minuscule

The study analyses 18 developed economies (Sweden, Romania, France, Ireland, Spain, UK, Bulgaria, The Netherlands, Italy, United States, Germany, Denmark, Portugal, Austria, Hungary, Belgium, Finland, and Croatia) between 2005 and 2015, finding that emissions decreased by a median -2.4% per year during that decade.

This is tiny – three times smaller than the yearly 7.6% cut of global emissions that would be necessary to meet 1.5°C Paris target (and this number is from 2019; the cuts would need to be even larger today). One striking example is France. The study indicates that France decreased its consumption-based emissions by a yearly -1.9% over the period with barely any GDP growth (+0.9%). Now compare this to the French climate target, which is to reach 80 MtCO2 by 2050, an 80% reduction compared to 2019 levels of emissions.

The UK is another case in point. The country is often lauded to have achieved the fastest experience of decoupling on Earth. In the Le Quéré study, its consumption-based emissions decreased by -2.1% per year between 2005 and 2015 with positive GDP rates of around 1.1%. This is not much in the way of decoupling; the country has pledged to reduce emissions by twice that amount (5.1% per year). To actually comply with the Paris Agreement, the UK must achieve a yearly 13% cut in emissions, starting now and for the decades to come. This is much – much – more than what green growth can provide.

The authors themselves err on the side of caution:

as significant as they have been, the emissions reductions observed […] fall a long way short of the deep and rapid global decarbonization of the energy system implied by the Paris Agreement temperature goals, especially given the increases in global CO2 emissions in 2017 and 2018, and the slowdown of decarbonization in Europe since 2014.”

Data from this year supports the authors’ precaution: de-carbonisation in many high-income economies has slowed down after 2015.

The fact that these rates are so small is worrying because we’re dealing here with the supposedly best country cases of decoupling. Assuming these rates can now suddenly accelerate would be like expecting Usain Bolt to triple his running speed. Even more unlikely, we would need all countries in the world to match the triple of these record levels.

Minuscule is a long way from enough   

In March 2021, the authors published a new study showing that 64 countries managed to cut their CO2 emissions by 0.16 GtCO2 every year between 2016 and 2019. This is good, but again, not good enough. And not good enough has dire consequences. To be precise, this is one tenth of what would be needed at the global level to meet the Paris climate goals; and if 64 countries managed to reduce emissions, 150 others did not. The latter increased their emissions by 0.37 GtCO2 each year. Put the two numbers together and you realise that global emissions have actually been growing by 0.21 billion tonnes per year.

This puts pressure on high-income economies. For developing countries to be able to increase their ecological footprint, affluent nations must reduce theirs as much as possible. Climate-neutrality at the national level by 2050 is not enough if we want today’s poorest to have the option of increasing their material consumption. And rates of reduction in rich nations of 1-3% are far from enough to compensate for the surge in resource use currently taking place in the global South.

This is only fair considering historical emissions. The global North is responsible for 92% of excess global CO2 emissions (the ones past the 350ppm threshold). For example, France has already overshot its fair share of the climate budget by 29.4 GtCO2. The Le Quéré study shows that it has decreased its emissions by 10 MtCO2 every year between 2005 and 2015. At that pace, and assuming carbon neutrality, it would take almost three millennia for France to resorb its climate debt.

Green growth without growth 

Emissions in the 18 studied countries decreased by -2.4% each year, but how big was GDP growth during that period? The answer: small. These economies grew by a median +1.1%. Denmark, Italy, and Spain are leading the decoupling pack with yearly carbon reductions of -3.7%, -3.3%, and -3.2% respectively. This, however, can hardly be called green growth because these economies barely grew – or actually receded (+0.6% of GDP in the case of Denmark, -3.3% for Italy, and -3.2% for Spain).

The authors acknowledge that this period is nothing extraordinary:

These reductions in the energy intensity of GDP in 2005-2015 do no stand out compared to similar reductions observed since the 1970s, indicating that decreases in energy use in the peak-and-decline group could be explained at least in part by the lower growth in GDP.”

So, the paper most popularly cited to assert that carbon-free economic growth is possible also shows that part of the decarbonisation is due to the fact that there was little or no growth. It comes as no surprise then that, using simulations, the authors estimate that

if GDP returns to strong growth in the peak-and-decline group, reductions in energy use may weaken or be reversed unless strong climate and energy policies are implemented.”

Sustainability is more than just carbon 

The authors’ study is about carbon, but carbon is one environmental problem among many others. Unfortunately, it is the only one that is adequately researched, with 80% of decoupling studies focusing on primary energy and greenhouse gases. This leaves only a few studies that have been conducted on other aspects of ecological breakdown, including material use, water use, land change, water pollution, waste, and biodiversity loss.

While there are a few inspiring stories of decoupling concerning carbon emissions, studies that track other indicators tell us a different story, one in which the economy is still strongly coupled with biophysical throughput. Materials are a good case in point. If the world economy was gradually de-materializing in the 20th century, this trend has since been reversing in the last two decades. This alone should temper optimism concerning an assumption of endless supplies of renewable energy, which after all, are dependent on the mining of finite quantities of minerals.

My point is that a “sustainable” economy in any meaningful understanding of the term must consider all the complex interactions it has with ecosystems, and not only carbon. A genuinely sustainable economy should not only be carbon neutral, but also remains within the regenerative capacities of all renewable resources, within the acceptable stocks of non-renewable resources, and within the assimilative capacities of ecosystems. Although sustainability ought to be understood as being about much more than only the condition of the biophysical environment, it seems evident that living within planetary boundaries is a minimum, non-negotiable condition for any kind of long-lasting prosperity.

Temporary decoupling

Mitigating environmental pressures in a growing economy not only implies achieving absolute decoupling from GDP, but also requires maintaining such decoupling in time for as long as the economy grows (recalling that emissions must be reduced by at least 7.6% every year from now on). Said differently, continuous economic growth requires a permanent absolute decoupling between GDP growth and environmental pressures. Yet, in the same way that economic growth and environmental pressures can decouple at one point in time, they can just as easily recouple later on.

This happens more often than we think. Let’s reflect upon the time when the International Energy Agency declared that decoupling was “confirmed” after observing a levelling of global emissions in 2015 and 2016. Yet, this decoupling was short-lived. In fact, it was mainly due to China moving from coal to oil and gas at the same time that the United States was shifting to shale gas. The shift was temporary. After that, economic growth recoupled with carbon emissions.

Situations of recoupling can also happen with renewables. In the decade between 2005 and 2015, Austria, Finland, and Sweden greened their energy mix and, as a result, lowered their emissions. But once this shift is complete, further growth will require an expansion of the energy infrastructure, which will imply additional environmental pressures. In fact, this is what happened after the studied period. Austria decreased its emissions by -0.6% in 2006-2010 and -1.6% in 2011-2015, but emissions returned  positive by +0.3% in 2016-2019. A similar story took place in Finland and Sweden; the rates of reduction accelerated between 2006 and 2015 but slowed down after that.

Some commentators hypothesized that the return of economic growth after the pandemic would be green, or at least, greener. Yet, global energy-related carbon dioxide emissions are on course to surge by 1.5 billion tons in 2021 – the second-largest increase in history – reversing most of the decline caused by the pandemic. The lesson from the corona crisis is this: slight oscillations from light to heavy ecological beating are not enough – we need to radically and immediately transform the economy.

Do we need environmental policies? 

Yes, we do and the Le Quéré paper is clear on that. We need energy and climate policies, “particularly if GDP growth increases,” the authors write. But what if capping GDP was itself considered an acceptable climate policy? This is the idea of degrowth. Since GDP remains significantly coupled with carbon emissions and other environmental pressures, a good way of limiting ecological wreckage is to put limits on the scale of the economy. If carbon emissions decreased by -2.4% with a +1.1% rise in GDP growth, imagine how faster they could be reduced if economic growth was not prioritised above the unthinkable risks of runaway ecological breakdown.

We know that stopping the growth machine leads to drastic emissions cuts because it happened during the pandemic. The slowdown of economic activity led to a historical reduction of global emissions: -7% compared to 2019. What happened through crisis could also take place in a more managed fashion in the form of a prosperity without growth in countries consuming more than their fair share of the global carbon budget. Of course, GDP is an indicator, not a policy button. There is thus a need for a diversity of sufficiency-oriented policies that will limit production and consumption, and speculative finance, especially in natural resource intensive sectors.

We should target emissions where they currently are, while ensuring that efficiency gains are not cancelled by more demand through rebound effects. For example, we could degrow aviation by setting airport quotas on the number of flights per day, restricting the construction of new airports and runways, and introducing a Frequent Flyer Levy (i.e. you get one levy-free first flight every three or four years, but the second flight bears a levy, with its amount doubling for each additional flight). Instead of hoping that the expansion of the aviation sector decouples from planetary damage, we could limit the scale of that sector to directly lower its emissions.

Decoupling is not enough

In sum, Le Quéré et al. (2020) report an observed decoupling in 18 developed countries between 2005 and 2015. But there are a few caveats. First, the rates of decoupling are a long way short of reaching even the most modest of national climate targets. Second, they are even more insufficient considering redistributive efforts required to achieve climate justice. Third, part of that decoupling is explained by low rates of economic growth. Fourth, the study period is limited and there is little to guarantee that what decoupling may have occurred will not recouple later on. And finally, the analysis is only about carbon and does not account for other environmental pressures.

So, is green growth happening? The answer is no, not really. As of today, economic growth is still a vector of resource use and environmental degradation. In high-income countries, the pursuit of additional growth might not even be socially beneficial, and particularly so if accompanied by widening inequality. Considering the increasing demand for resources in the most disadvantaged regions of the world, the continued obsession with growth in already affluent nations is becoming untenable.

Decoupling is simply not enough. Instead of struggling to “green” expanding economies, we should reroute the task by mobilizing sufficiency-oriented strategies like degrowth and post-growth. Eventually, both efficiency and sufficiency are dearly needed. One thing is resoundingly clear, what we need to do away with is the growth-at-all-cost mentality that sacrifices social-ecological health to prioritize GDP above all else.

Teaser photo credit: Source: Cabinet Office | Flickr