Degrowth, Not Efficiency, Is What Matters

I want to thank Marian Tupy and Gale Pooley for their thoughtful and collegiate response. The thesis of my “wide-ranging” essay, though, was slightly different than what they responded to. I argued that the debate between self-professed optimists and pessimists exemplified by the Simon-Ehlrich wager is past its sell date. Ever since Malthus, these positions are two sides of the same coin, foreclosing nuanced ways of understanding and confronting problems. Freedom, I argued, is not about eschewing each and every limit, but knowing how to set your limits (individually and as a society), and protect your and others’ freedoms.

Following this cornucopian vs. Malthusian (or optimist vs. pessimist) scheme, Tupy and Pooley place my opinion in the pessimist camp (even though I insisted I am an unrepentant optimist who believes that social and political movements can change societies for the better – but I don’t let my good spirits thanks to my privileged upbringing and happy life blur my scientific judgement). They respond to claims I was supposed to make, but didn’t—claims about thresholds, collapse, and overpopulation, while missing those I made about limits and freedom, abundance through limitation, or Malthus as a proto-growthist—claims that do not fit the procrustean bed of a 1970s bet.

Sticking to the bet’s scheme leads Tupy and Pooley to contradictions. They say that optimists like them welcome the slowing down of population growth (I do too!), but then they see “under-population” (sic) as a worrying development. In their first essay they celebrate endlessly growing material extraction; in their response they want to prove that material extraction will go down.

Granted, I did talk about prospects of a climate breakdown, but whether this happens at 1.5, 2 or 3 degrees C is beyond the point. The hotter it gets the worse, and at some point a breakdown precipitates, that much we know. The fact that observed thresholds in ecosystems are uncertain does not change that. I do not use the word “collapse” out of respect for the billions living in conditions that would scare us Westerners as “collapse.” Kim Stanley Robinson’s novels The Ministry of the Future and New York 2140 offer a glimpse of what a climate-altered world could look like—not a Mad Max–like collapse, but it doesn’t look good either. If we are imaginative and innovative, we have to do our best to stop this from coming true.

Tupy and Pooley argue we are already doing our best—carbon emissions per unit of GDP are going down. The atmosphere though is indifferent to emissions per GDP—the planet heats because of emissions, period, and these still increase with GDP. I had already noted that a few high-income countries do reduce emissions while growing. Tupy and Pooley did not respond to my observation that, one, the rates of these reductions are nowhere near what is necessary in relation to staying within—and sharing fairly—the remaining carbon budget[i]; two, these decreases have been possible due to the Great Recession (with 3% annual growth the United States or the EU would not have reduced carbon emissions). As I also argued, without response, the most optimistic projections, assuming the best possible implementations of national commitments, get us to 3C or more of global heating. Scenarios try to square growth with a safe climate by imagining untested and unlikely “negative emission technologies.” If we do not want optimism to turn into complacency and “sit idly by and allow environmental problems to overwhelm our planet” (Tupy and Pooley’s words), then we need to start recognizing the enormity of the challenge.

Tupy and Pooley are confident we will rise to the occasion given “our species’ track record of tackling past challenges.” Yet not all civilizations tackled their challenges soon enough, otherwise they would still be with us. Two hundred years of industrial civilization are too short for pronouncing what will happen the next few centuries, less so eternity. If we had found ourselves in Europe in 1938, we would be wrong to think things are about to get better, just because resource use and life expectancies increased from a century ago. There is no universal, much less automatic, arrow of progress. Don’t get me wrong: I don’t deny the improvements Tupy and Pooley list. Progress does take place: in specific times and places, with shifted costs, and with the danger of reversal (as Joseph Stiglitz notes between 1989 and 2013 median household income in the U.S. shrank by 0.9%; whereas life expectancy in Spain where I live, fell by one year in 2020).

When resources get scarce, markets make sure substitutes are developed, Tupy and Pooley argue. Leaving aside Philipsen and Trebeck’s corrective to how markets work, I fail to see the connection to climate. There is no price for carbon, and powerful interests oppose carbon taxes that compromise their profits (they oppose even carbon markets, the abandonment of the Kyoto protocol a case in point). There are clean energy substitutes, but often—not always—they are more expensive than fossil fuels. The level of carbon taxes currently discussed, with dim hopes of being implemented, is nowhere near that necessary for averting dangerous climate change. Unless Tupy and Pooley specify how they see markets/prices being implemented and changing the current dynamic, it is hard to share their confidence.

Improvements in other environmental fronts do not necessarily tell us much about climate change. I find it counterproductive to throw back selective environmental data showing that in many fronts things do get worse. Let’s just agree that the picture is much more complex than Bjorn Lomborg, Michael Shellenberger and their likes paint it. Let me focus on just one aspect, material use, that I happen to know well, given also that it was the central point of Tupy and Pooley’s response. No, dematerialization is not taking place “changing the world”—rather it is the world that is changing (globalization) giving a false impression of dematerialization.

It is good to distinguish here relative (that is, kilograms per GDP) and absolute (that is, kilograms total) resource use. An elephant uses fewer resources in relation to its weight than a mouse, but it would be strange to claim that an elephant is a dematerialized version of a mouse. Resource and energy productivity are bad indicators of sustainability. In a growth-oriented economy, increasing resource productivity does not necessarily lead to declining resource use, just as increasing labour productivity does not lead to less employment or work. Yes, statutory limitations on working hours or resource use can reduce work or resource use and translate productivity gains into less work or extraction—but as long as productivity gains are reinvested to grow output, work or resource use increase.

Andrew McAfee claims that high-income countries have turned a corner, and now use fewer resources, producing more – consumption of a range of metals and resources in the U.S. has indeed been declining. What is surprising is that McAfee is surprised, given the monumental move of manufacturing out of the U.S. The iPhone example is instructive here. Apple’s profits on the iPhone get captured as GDP in the United States. But physical production of the iPhone takes place almost exclusively in China. Related resource use counts as China’s.

To calculate the real resource use of the American economy one needs to look at the materials used to produce all the goods Americans consume, which underpin US GDP. The best way scientists have come up with is the ‘material footprint’ method. As I showed in my essay, footprints in high-income economies, such as the American economy, continue to grow hand in hand with GDP (in line with the picture of global GDP growing alongside resource use). The method is not perfect and rests on proxies or models, but this is no reason for counting domestic consumption instead, a misleading indicator for a globalized world. GDP, a problematic indicator of welfare, does capture market activity - analogously, material footprint, imperfect as it is, correlates well with other indicators of environmental damage. Aggregating different materials into a single number is problematic (as is aggregating the sale prices of different goods and services in GDP), but similar tendencies appear if one disaggregates footprints per category of material. Separate studies also point to the same direction. Water use, for example, declines in California, but water footprint grows.[ii]

To produce a 300g smartphone, we use 44.4 kg of natural resources (for a computer, it’s around one metric ton). Yes, an iPhone concentrates services for which more physical goods, materials, and energy were used (though I can’t imagine anyone storing thousands of albums, yearbooks, and photos in their houses; and I know many of us who don’t have only an iPhone, but also a desktop, a laptop, an iPad, and an older iPad collecting dust). Often instead of substituting old goods, new goods just add on. The computer did not bring the paperless office—each year the amount of paper produced by the average company grows by 25%.

Yes, resource efficiency is crucial. But if we do more, even with less, we will use more. The more efficiently we use something, the cheaper it gets, and the more of it we end up using. The point is to do less. Tupy and Pooley get actually the iPhone example from a paper that proposes a climate mitigation scenario of energy efficiency and sufficiency, what some call “energy degrowth” given the dramatic decrease in energy demand it foresees. This scenario proposes a drastic downscale of energy needs and a shift to more efficient ways of meeting these needs. And that’s the way to go.

Tupy and Pooley may be right that electorates have little appetite for degrowth. But as I had argued in my essay, growth may be coming to an end—and the question is whether we adapt and find ways to secure wellbeing, or whether we sacrifice what we have to keep growth going. As the experience of the pandemic shows, people want governments to get their act together and protect them from calamities and economic shocks—and there is no bigger shock than a climate breakdown.[iii] It is illiberal governments instead, from Brazil and India to the Philippines or Turkey, who vow to sustain growth at all costs, at the expense of civil liberties and the health and wellbeing of their citizens.

Tupy and Pooley challenge us to a bet with McAfee if we think that material use and carbon emissions will keep increasing in the United States. No, I don’t think that emissions will keep increasing (material footprints may). I doubt that emissions or footprints will decline fast and sufficiently, especially if growth rebounds. If I were still an undergrad student playing poker and dreaming I am the Cincinnati Kid, I would take McAfee’s wager. But I would call his bluff and ask him to bet that the United States will reach its fair share of emissions and resource use by 2040 while growing—not just that it will decrease them from their exorbitantly high level.[iv]

Luckily, with age I know better, and I don’t play poker anymore, nor do I put bets. I won’t put a bet because for the good of all of us I hope the United States and other high-income economies do reduce their emissions fast and drastically. I won’t put a bet because as a scientist I know that all knowledge about the future is uncertain, and I may be wrong—I want to be free to change opinion if facts force me to. Betting on our common future is silly. Let the Simon-Ehrlich bet rest in peace.


[i] Le Quere et al. ( write that countries which have achieved some sort of decoupling between CO2 & GDP showed decline in CO2 of 2.4% p.a. on average between 2005 and 2015. Kevin Anderson calculates that for high-income countries the decline in line with a fair share of remaining carbon budgets needs to be close to 11% per year:

[ii] Fulton, J. 2015, California’s Water Footprint: recent trends and framework for a sustainable transition, Unpublished PhD thesis, University of California Berkeley.

[iii] Tupy and Pooley point to the Gilets Jaunes revolt against a new carbon tax in France. Our empirical research with Rimel Illel and Christos Zografos of the Gilet Jaunes and our interviews with protesters show that the reaction was much more complex than the media portray it. Protesters revolted not only because of the rise of diesel prices, but also because of perceived unfairness. A common feeling was that the proceeds would be used to fund a wealth tax cut. There were complaints also about lack of transparency in the government’s intention about the destiny of the funds, and the lack of viable public transport alternatives in the countryside, where diesel cars are the only means of transport for low income groups.

[iv] If the United States achieves its target of ~50% reduction by 2030, its per capita emissions will still be higher than the EU’s today, and more than double the global South’s average.

Also from this issue

Lead Essay

  • Marian Tupy and Gale Pooley argue that empirically speaking, resources are growing more abundant, not just as measured by inflation-adjusted price, but as measured by time prices: An hour of labor today generally buys a lot more than a comparable hour in the past. Additional human beings add to our economic capacity rather than diminishing it, because people are the solvers of economic problems.

Response Essays

  • Giorgos Kallis argues that we shouldn’t want economic growth to continue indefinitely. Nor will it do so. The relentless pursuit of economic growth will eventually lead to a collapse. Better, says Kallis, is to aim for prosperity without growth, which he calls “the defining challenge for twenty-first century economics.”

  • Katherine Trebeck and Dirk Philipsen say that the relentless pursuit of economic growth is harmful in the long term. While poverty should be alleviated, there is such thing as material sufficiency, and unfortunately, markets don’t always point at it. Often, they encourage us to substitute harmful products for beneficial natural goods. Developed economies should reposition themselves to provide economic stability, human dignity, environmental protection, and healthy communities.