What Microorganisms Can Teach Us about Decoupling and Limits to Growth

Last week, noted environmentalist George Monbiot declared the imminent demise of farming. He profiled a company that has engineered microorganisms to use hydrogen extracted from water to produce flour. If this technology scaled up, expanded to other foods, and was powered by clean energy, it would theoretically give humanity and the planet something near a free lunch. “We are on the cusp of the biggest economic transformation, of any kind, for 200 years,” Monbiot writes. “While arguments rage about plant- versus meat-based diets, new technologies will soon make them irrelevant. Before long, most of our food will come neither from animals nor plants, but from unicellular life.”

While Monbiot radically overstates the imminence of such a transformation, the large scale production of landless food isn’t impossible, nor is the idea unprecedented. But, as a thought experiment, the idea also has something to teach us: the main thing standing in the way of an affluent future with a stable climate and ample room for wild nature — the most important “limit to growth,” as it were — is cheap, clean energy.

Unsurprisingly, Monbiot’s piece inspired a flurry of criticism. Twilight Greenaway wrote a defense of farming and an implicit call for more of us to return to agricultural work, declaring that “[t]he more people we have on the land, working to truly understand the intricacies of ecosystems through farming, the better chances we have of achieving an agriculture that both helps mitigate the coming climate emergencies, and prevents them from getting worse.”

It’s hard for me to make reasonable sense of Greenaway’s argument, who also touts the benefits of a slew of farming practices that are widely acknowledged to require more land. With so many people in low income countries wishing liberation from subsistence farming, and given that the per capita land requirement of global agriculture is roughly half what it was in 1960 thanks to rising productivity (i.e., “intensive” farming), it’s hard to know how to engage with the notion that a return to mass participation in lower-yield agriculture is where the solution lies.

In contrast, I get where Monbiot is coming from. I spend a fair share of my time thinking about environmental impacts in general and deforestation in particular — and the role of agricultural expansion in driving it. Forests — and natural habitats in general — could really use a break, yet in light of a growing population, higher food demand, and stagnating growth in yields, further growth in farmland seems almost inevitable. There are many things we can do to reduce farmland growth — from raising agricultural yields to reducing meat consumption — but most of them, with the possible exception of plant- or cell-based meat, are incremental. Will yields grow by 1.5 or 1.7 percent per year? Can we reduce beef consumption by 5 percent? While I’m acutely aware of the potential impact on the lives and livelihoods of farmers and farm workers from abandoning large-scale farming, some days I get a little impatient and just wish there was something more radical, something that could liberate large amounts of land from human uses in one fell swoop. Edible microorganisms present just such an opportunity.

The theoretical potential of what Monbiot refers to as “farm-free” food is enormous. The idea also isn’t new. As they say, if you want a new idea, look to an old book. In 1967, the British science writer Nigel Calder published a book called Eden Was No Garden, with exactly that sort of vision. True to the early post-war modernist style of ambitious optimism (a precursor to ecomodernism, as it were), what Calder had in mind was the end of agriculture as we know it. “The provision of food,” he wrote, “still centers on the idea that the right way to do it is to catch the energy of sunlight in the green leaves of traditional cultivated plants spread over millions of square miles of the earth’s surface.” In Calder’s view, “we must now turn to methods of producing food that are the very antithesis of agriculture, in the sense that they do not require large tracts of land… It is, I believe, only a matter of time before engineers build factories that can make most or all of the kinds of food we need.” This was agriculture’s “too cheap to meter” moment, now brought back to life by Monbiot.

Some days I get a little impatient and just wish there was something more radical, something that could liberate large amounts of land from human uses in one fell swoop. Edible microorganisms present just such an opportunity.

Calder didn’t actually know how this would be done — no such technology had really been developed back then — but today it’s possible, as Monbiot points out. Producing food this way obviously requires a serious amount of industrial infrastructure for the factories, but in terms of land, the requirements are diminutive, in large part because the food production takes place in three-dimensional structures as opposed to two-dimensional fields. Tomas Linder at the Swedish University of Agricultural Sciences estimates that replacing all soy production in the US would require a land area of about 20,000 hectares, which sounds like a lot until you realize that it’s about 0.06% — less than one-thousandth — of the area it takes to grow all that soy. In a different paper, Pikaar and others estimated that substituting just 2% of the dry matter in livestock feed by 2050 could spare over 100 million hectares of land from agricultural conversion. Fields, as Calder noted, are ”in principle simply large and unwieldy surfaces for the inefficient collection of sunlight.”

There is one catch, though, other than the sheer cost: energy. The microorganisms need an energy source, which is typically some combination of carbon dioxide and hydrogen gas. You can get the carbon dioxide from existing fossil fuel plants (through carbon capture) or directly from the air, as several startups are now trying to do. Or, like the company does that Monbiot profiles, the hydrogen gas can be produced from water, with oxygen as the only by-product, though running the electrolysis is an energy intensive process.

A back-of-the-envelope calculation suggests that the scenario in which 100 million hectares of land is spared by replacing feed crops with microbial biomass would require something on the order of 300 GW just to run the electrolysis that supplies microorganisms with hydrogen gas. That’s approximately 300 large nuclear power plants, about two-thirds of the current global number. Try to replace all cropland and the numbers verge on the absurd. We’ll have enough trouble just replacing our existing stock of fossil fuel facilities by 2050, let alone build another global infrastructure to replace cropland.

Perhaps some time toward the next century, with a clean energy infrastructure — maybe even fusion — and highly advanced, wealthy societies, we might think about realizing Calder and Monbiot’s vision in a serious way. Until then, we should do as much innovation in land-less food and feed production as we can, and use these technologies in a more modest way to make use of waste streams and other microbial feedstocks that aren’t as energy intensive.

In spite of the current impracticality of large-scale, landless food production, there are two things that these microorganisms can teach us. First, they present a theoretical pathway to radical decoupling of environmental impacts from economic growth, the possibility of which Monbiot himself, among many others, has denied. “Green consumerism, material decoupling, sustainable growth,” Monbiot has previously written, “are illusions, designed to justify an economic model that is driving us to catastrophe.” Yet farm-free food is the ultimate decoupling and depends on advanced technology that is born of affluence.

Second, they show that ultimately, the most important limit to growth is energy. What Monbiot describes is a scenario where food production would not depend on the climate, or the sun, or the availability of arable land — it would not depend on a whole lot in terms of raw materials at all, other than for building the factories themselves — and it could be done in a way that is basically carbon neutral. And energy itself can in principle be unlimited, especially with fusion. Come up with any environmental problem and I’m pretty sure that with enough clean energy (and a big enough budget) we can fix it. It might entail other less desirable consequences — any big solution tends to do so — but we can’t say it’s impossible. The real barrier to a world of nine or ten billion wealthy people with a small environmental footprint is not any inherent ecological carrying capacity, but rather technology, and the institutions that create and sustain it.