PhD in physics (thermodynamics of ecosystems) and in moral philosophy (animal rights), master in economics, researcher in health and welfare economics at KULeuven, president of EABelgium, environmental footprint analyst at Ecolife

Topic Contributions


The case against degrowth

“As you mention, increases in efficiency tend to be followed by equal increases in consumption in society absent other incentives and policies. So it's understandable that some people might think we need some limits on resource extraction.”>I think it is better to have limits on environmental impact. Price mechanisms such as a carbon tax can be used to counter rebound effects on environmental impacts.


“The 40 hour work week was once unthinkable. So were child labor laws. So was a ban on CFCs.”> Economic growth made these policies much more politically feasible.


“What if people had just given up?”>Anti-degrowth environmentalists are not saying we should give up. They say we should invest more in technological innovation.


“Technology does not develop in a political vacuum, and we would not have seen over 90% cost reductions in technologies like solar during the past 10 years without major investments and support from the Obama administration.”>These are points primarily used by anti-degrowth environmentalists to argue for the importance (effectiveness) of more government funding of clean tech innovation. Degrowth environmentalists, on the other hand, are more skeptical about the importance of such clean tech innovations: they prefer a shrinking economy, where we have less money available for technological research. Looking at degrowth thinkers, organizations, panels and declarations, you don’t see a promotion of increased clean tech innovation funding. It is definitely not a top policy proposal. What you do see, is an explicit rejection (proposal to ban) of some technologies such as genetic modification, nuclear power and nanotechnology, a moratorium on techno-scientific research, an orientation research toward low-tech research and convivial tools, raising awareness about “technological addiction”, opposing digital technologies in education. These are not really helping the acceleration of clean tech innovation. 


“Reducing carbon emissions is an example of "degrowth" in one sector of the economy.”> The energy sector can still grow, even when decarbonizing.


“The wealthiest 10% of the world are responsible for over half of emissions in 2015.”> But they own 85% of the wealth. Hence, per unit of wealth, they emit less. Suppose you had a policy that annihilates 85% of global wealth, namely all the wealth owned by the richest 10%. The richest 10% can no longer consume anything. That would only reduce emissions with 50%. With clean tech innovation, we can reduce more than 50% of emissions, without such politically unfeasible policies as 85% wealth reduction. 


“And we know that happiness barely increases above $75,000 a year,”>Environmental impact also shows such a diminishing marginal effect. Above a certain income, someone’s environmental footprint barely increases when income increases. Richer people have a higher propensity to save than to consume. In high income countries, we see that an increasing income over time even correlates with reduced CO2 emissions (absolute decoupling). Cfr environmental Kuznets curve.


“so is rising GDP really benefiting most people when it mainly goes to the top 10%?”> The rising CO2 emissions mainly go to the bottom 90%...


“For example, banning all new fossil fuel extraction and creating a carbon tax that is used to fund clean energy jobs”>This is not specifically a degrowth policy proposal. Anti-degrowth environmentalists also favor such proposals. Such proposals are compatible with economic growth.

“Most people would prefer to work less so that they can spend more time with friends, family, and passion projects.”>They can choose to do so, in a free market. At least when the labor market is competitive and flexible enough, such that it is easier to chose a job that has less working hours. Instead of degrowth regulations (e.g. maximum work hours per week), it is more effective to increase job flexibility. 


 “and hoping for the best with technology investments.”>You can also say that degrowth environmentalists hope for the best with degrowth campaigns, with income and working hour regulations,…

“1. Why shouldn't we set sustainable limits on resource extraction and continue to invest in technology?”> Sure, let’s do that. But only set limits on resource extraction when that resource extraction really correspond with environmental impact. What would be the sustainable limit for energy use? Suppose you set a limit on energy use per capita. e.g. 50 kWh per day per person. Now I invent a clean technology, namely feasible nuclear fusion, that can generate trillions of kWh per day. Is my invention not allowed, merely because you chose a limit of 50 kWh/day/person? 


“Why is ignoring the possibility of running out of resources and betting everything on innovating our way out of all of those limits within a few decades better than a more careful approach?”>If you prefer degrowth, then why do we not have a degrowth world? Why don’t you just make the global economy degrow? Perhaps it is difficult, but then you are betting on feasibility of changing the global economy. In the end, we are interested in cost-effectiveness. Which policy campaigns are most cost-effective: a campaign for degrowth with e.g. income and working hour regulations, or a campaign for increased government funding for clean tech R&D (funded by a carbon tax or an income tax)? Suppose the economy (GDP) grows, and only 1% of the extra income is taxed. This should be extremely feasible. If these tax revenues go to clean tech R&D, we double funding for R&D, which could almost double tech innovation, which could almost double the speed to implement these technologies. We saw a 25% reduction in consumption-based per capita CO2 emissions in dozens of high-income countries in 15 years. Imagine we have in 15 years a 50% reduction…


“There are plenty of people who chop down an entire forest today for a quick buck rather than harvest sustainably in perpetuity, even if the latter would generate more wealth in the long run.”>Why would they chop down the forest so quickly? Because the interest rate is high. But that basically means the marginal productivity of capital is high. Selling the wood and investing in capital, might be the most efficient (productive). Once marginal productivity of capital declines, a lower harvest rate would become optimal. In other words: there is not necessarily a market failure when chopping down a forest. But you may refer to the real underlying market failure: the decrease in a public good such as biodiversity. The most effective policy interventions to solve that problem of biodiversity loss due to clearcutting too much forests, is a taxation, and funding tech innovation to have better alternatives than wood (substitutes for wood).


“2. A lot of people would rather have more time and meaningful work than money. Why should we ignore their preferences”> Why would they not simply choose to work less, if that is what they prefer? Whatever the reason you come up with, I honestly don’t think that economic growth is the main obstacle or reason why they are not so able to choose fewer working hours and more leisure time. In contrast: we do see a negative correlation between economic growth and working hours: a higher GDP correlates with fewer working hours.


“3. It's not clear to me that all increases in growth and consumption necessarily mean greater happiness, creativity, and innovation forever.”> And it is not clear to me that all decreases in growth and consumption necessarily mean lower CO2 emissions and environmental impacts.


“Why not reduce certain kinds of consumption and use those resources to increase investments in innovation?”> Sure, but that is not incompatible with economic growth.

The case against degrowth

I didn't particularkly steelman degrowth, because I thought the arguments in favor of degrowth are pretty obvious: you can decrease environmental impact by reducing economic activity and resource throughput. I tried to find reasons why such reductions would be most feasible and most effective, but couldn't find them.

"I don't think reducing population is a universal, or even dominant, objective amongst people who support degrowth."> That's why I called it the population degrowth approach, to be distinguished from the resource degrowth aproach. The common usage of degrowth refers to resource degrowth. but population degrowthers are arguing in just the same way as resource degrowthers, that reducing X (be it economic activity, consumption or usage of dirty technologies) is not enough, just like resource degrowthers are arguing that reducing Y (e.g. usage of dirty technologies) is not enough. Population degrowthers are skeptical about the potential of consumption reductions (econo-fix), just as resource degrowthers are skeptical about the potential of technology innovations (techno-fix).


"2) It seems pretty clear that rich people produce a lot more emissions - e.g. reports like this or this highlighting huge disparity in emissions between the richest 1% and the poorest 50% globally."> True, but those richest 1% created 82% of the economic wealth (also from the same Oxfam source: According to your Oxfam reference,  the richest 1% cause 15% of  carbon emissions. Hence, 82% of created economic wealth corresponds with only 15% of emissions. If you would reduce all economic wealth creation by the richest people, which means reducing it with 82%, you only reduce carbon emissions with 15%.  This proves again my point about the non-linear relationship between GDP (created wealth, income) and carbon emissions. Income growth shows a decreasing marginal environmental impact. That makes degrowth measures like income ceilings less effective. 


"3) It's quite possible capitalism has led to people working more, not less. While a chart like this shows a decline in working hours since the end of the Industrial Revolution, it's quite plausible people worked far less before the Industrial Revolution"> That could be true, but as long as degrowthers are not arguing to move back to preindustrial societies, I don't think this point is relevant. Plus, importantly: humans have longer lifespans now compared to preindustrial times. That means it could be the case that I still have more leisure time over my whole life, than someone in the 16th century over her whole life.  And what about our pensions? They didn't have that in the 16th century. 

The crux of the cultivated meat feasibility debate

Thanks for the question, had to think a while. About infeasibility of cultivated meat, best counterevidence for me would be seeing a massive disinvestment in cultivated meat R&D, a consensus among researchers openly saying that it is too difficult to make progress.

Another crucial thing that would change my mind, is evidence about the feasibility of plant-based meat, that substitution towards plant-based is faster than I would expect (faster than cultivated meat innovation). This would mean seeing a fast increase in the number of vegans, and especially conservative male meat identifiers switching to plant-based meats.

The crux of the cultivated meat feasibility debate

The more I think about it, the more I start to believe that cultivated meat is feasible, and that your examples offer some evidence.

So consider the function of flying. You may say that the function of flying with wings cannot be fulfilled with technology, that  imitating nature does not work . But your examples refer to humans flying with technologies that use wings. But humans are much heavier than birds. With airplanes, we can fly faster, over longer distances and carry heavier weights, things that biological organisms were never capable of doing. And we are talking about many orders of magnitude faster, further and heavier. Why would the functions necessary for muscle cell growth (e.g. oxygenation, nutrient production, waste removal,...) be any different? Why would these functions never be able to be fulfilled at least as efficiently with technologies than with organs?

Then you offer the example of ornithopters, and I conclude that even imitating nature is possible. The function of flying with wings can be imitated with technology. Those ornithopters are as heavy and large as birds. Some of those ornithopters even use artificial muscles (polymers that can contract like muscles). So the function of muscle contraction can also be replicated.  Some ornithopters have machine learning AI such that they can learn to fly, which means the function of brains can be replicated. So the complex combination of functions "learning to fly with wings using muscle contractions" can be replicated. What more evidence do you want that technology can build tools that fulfill complex functions that are fulfilled by biological organisms?

Cultured meat: A comparison of techno-economic analyses

One more addition to the cultivated meat feasibility discussion:

I argue why we have to make a distinction between the functions (e.g. taste, nutrition,...), the products (e.g. muscle-based meat, plant-based meat) and the production processes (e.g. animal-based meat, cell-based meat).  I expect that cell-based meat is feasible (can reach price parity with animal-based meat), but that we are uncertain about the time frames for innovation (of cell-based meat) versus substitution (towards plant-based meat). Given these considerations, cell-based meat research and development has to be considered more like an insurance policy.

New Intuitions for Cultured Meat

I wrote a comment in a previous discussion about why I think cultivated meat can be expected to become at least as efficient/cheap as animal-based meat:

The basic idea is that animals were not evolved to maximize meat production. Just like horses were not evolved to maximize transport efficiency and hence were replaced by cars, plants were not evolved to maximize turning solar energy into electricity and are replaced by more efficient solar panels, pigs were not evolved to maximize insulin production and were replaced by recombinant-DNA yeast,...

Cultured meat: A comparison of techno-economic analyses

Concerning "it is a matter of time": the only worry that I see, is that it would take so long to develop cultivated meat that in the meantime we would have already abolished animal farming (or decreased it to such a degree that cultivated meat has little additional value) because of e.g. plant-based and fermentation-based protein. But I consider that unlikely (lower than 10% likelihood). Oh, and even if humans would be all plant-based vegans by then, then we still have the many carnivorous animals (pets,...) who may benefit from cultivated meat. Hence, I think speeding up cultivated meat R&D remains very effective (high risk high impact), especially for animal welfare. It may be less effective for e.g. climate change, because reductions of greenhouse gas emissions need to occur soon (within 30 years). But cultivated meat offers a cheap carbon capture and storage method (reforestation of agricultural land that was used for livestock). And I think carbon capture is still worthwhile even over 50 years.

I would say 30-50 years for whole tissue cultivated meat to reach price parity with animal-based meat. But I have no clue whether I'm good at forecasting.  

About the 50% consumption of resources: that was just an assumption, somewhere between 0 and 100%, close to what I think is the proportion of edible tissue mass to whole body mass.

Cultured meat: A comparison of techno-economic analyses

Please sure do! That would be very interesting.

Cultured meat: A comparison of techno-economic analyses

I would expect that cultivated meat can reach price parity with animal-based meat, based on 'first principles'. Assume that all biological functions in an organism can be replicated with technologies, and that these technologies can reach the same efficiency as the biological functions that reached high efficiency due to evolution and natural selection. That is a realistic assumption, because no laws of nature have to be violated. To grow muscle tissue, we need oxygenation, so we invent a technology, call it 'lungs'. We need nutrients (amino-acids, sugars,...), so we invent a technology called 'intestines' to produce nutrients (e.g. from plant-based sources). If these new technologies are as efficient in doing what they have to do as their organic counterparts in animals, the production costs of cultivated meat and animal-based meat will be the same. However, using animals to produce muscle tissue is not maximally efficient, because of two reasons.

  1. The animal wastes resources (nutrients, energy) on unnecessary organs, tissues and body parts, such as brains, eyes, ears, tails, feathers, pain receptor cells, reproductive organs, hooves,... All these things are not necessary to grow muscle cells. Assume that these unnecessary body parts use 10% of nutrients and energy. Then a production unit (e.g. bioreactor) that does not use these body parts can be 10% more efficient and hence 10% less costly. 
  2. Using an animal to harvest muscle cells, the many other body parts that are necessary for muscle growth, such as the lungs (for oxygenation), intestines (for production of the growth medium), skin (for thermal isolation and protection),... need frequent replacement when the muscle cells are harvested, because these body parts are destroyed (in the slaughterhouse). It is like using a bioreactor to grow cultivated meat, and after each batch, we destroy the whole equipment, including all sensors, tubes,... And then we built a new bioreactor (using a factory we call 'uterus'). That is not efficient, and very costly. I expect not having to construct a new production unit after each production cycle, will make cultivated meat production much more efficient (and hence less costly) than animal-based meat. Assume the production unit for animal-based meat (the necessary body parts, such as the lungs, intestines,... of the animal) consumes 50% of resources for its construction (growth), not having to construct so many production units could save almost 50% of resource use and hence costs. 

So I expect with sufficient research, it is only a matter of time when cell-based meat reaches price parity, and it can perhaps drop to 50% of the price of animal-based meat. Plus, I consider it unlikely that none of the technologies can become more efficient than their organic counterparts, because it is unlikely that the current design of an animal is optimal (meaning that the current animal would have reached the final stage of evolution and that none of its organs can be improved).

Cultured meat: A comparison of techno-economic analyses

What is the packing density of muscle cells in muscle tissue (meat)? Why not use that packing density as an estimate for the maximum possible packing density of muscle cells in a bioreactor?

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