One of the greatest threats to life on Earth is poetry. George Monbiot, in Regenesis (2022).

Our pastoral stereotypes conjure up a picture of a shepherd boy patiently tending to his flocks, probably sat cross-legged on a rock, playing a rough-hewn flute, while flower-dappled meadows stretch into the distance. This trope can be tracked back to the Classical era, bolstered by later Christian iconography, but is a long way from the prosaic reality of livestock farming. Western culture has fixed upon pastoralism as the epitome of harmonious living with nature when it is anything but. As George Monbiot points out early in his latest book, Regenesis, the real population challenge faced by the world today is of livestock numbers, not humans.

The goal of this book is to find a path towards an agricultural system which is simultaneously more robust and sustainable, while providing humanity with sufficient food that is nutritious and affordable, but not trashing the planet in the process. That he has named the problem and engaged with it so constructively is impressive, and I recommend that everyone reads this book. Personally I’m not wholly convinced by his solution, although it would be a lot to ask to split this Gordian knot all at once. Despite my misgivings there is a lot to support and recommend.

His solution for the livestock crisis can be distilled into three parts. The first is that our diets need to dramatically reduce their association with animal products. Not everyone needs to follow Monbiot’s own path and adopt veganism (I certainly haven’t), though there’s little doubt that it would be beneficial for the health of the planet and likely ourselves too. Excluding meat, eggs and dairy products is not essential but we certainly require far less of them than we currently consume, and First World levels of demand cannot be extended to the whole human population without running out of land area in which to produce them.

In one of his most strikingly counter-intuitive arguments, Monbiot provides convincing evidence that extensive, low-intensity or organic approaches to livestock production can only have a limited role in future food production. He is surely right here insofar as they inevitably require greater land areas, eroding natural habitats still further. If the outputs are only premier foods for elite consumers then they will do little to resolve the coming food crisis.

Rather than becoming an evangelical vegan, a position likely to be either mocked or ignored, Monbiot recognises the important cultural role played by protein-based foods and seeks out alternatives. He finds great hope in fungal fermentation. Meat substitutes are now becoming commercially available and increasingly accepted by a public who are at least curious and, if price becomes a factor, will likely embrace them willingly.

This is the first area where I have some scepticism. While it is certainly true that meat substitutes can effectively replace (and even be superior to) low-grade, mass-produced meat products such as burgers, mince or chicken nuggets, this is a low bar to reach. These foods are valued for their lack of inherent flavour and ability to absorb other ingredients; that they are derived from meat is almost incidental. The attachment to a real roast chicken, sirloin steak or mackerel is going to be harder to break. Still, replacing the large and growing fraction of the global food market made up effectively of interchangeable protein lumps would be a valuable service.

Then, however, comes the question of who produces it. Monbiot conjures an idealistic vision of small-scale, distributed technologies that place protein manufacture into the hands of communities throughout the world. Perhaps your protein lumps could be picked up on your local high street next door to the baker or costermonger. More likely, however, is that economies of scale will mean that such enterprises will be undercut by larger industrial manufacturers. This runs the risk of reducing the resilience of global food systems, reproducing one of the crises that Monbiot identifies in our current situation. Factories under the control of small numbers of corporations, investors or governments become sources of inequity and vulnerable infrastructure at times of conflict. I fear that we could simply end up transferring systemic risk from one limited set of power-brokers to another.

The book then turns to arable production. A staggering fraction of the world’s crops are used to feed livestock, and one of the immediate benefits of a reduction in animal consumption would be the freeing up of large amounts of land which could then be used to feed people, or turned over to nature. This is an easy win for conservation and humanity alike, and therefore hard to argue with.

Nevertheless, arable crops remain the major source of calories for most of humanity, resting upon high-intensity production of a few staple grains. We will need to continue to grow crops even in the absence of livestock. Once again Monbiot directs some unexpected friendly fire in the direction of those who advocate for various forms of low-intensity agriculture such as high-nature-value farming, organic production or no-till systems. These are all more beneficial to nature and more sustainable than conventional agriculture, but share the common weakness that they not currently profitable (nor likely to be under any plausible model), and increasing their scale would only reproduce the problem of extensive agriculture. Less bad farming is still farming. I agree with him here. There is a niche market for the expensive products of agro-ecological farms but they won’t feed the world.

Monbiot places his hope in another innovation: perennial crops. What if, instead of the wasteful and polluting cycle of planting, harvesting and ploughing, we could grow crops that would last for multiple years? Intensive arable cultivation will always be necessary but through natural weed suppression and reduced soil erosion it could be closer to sustainable.

For me this is the part of the story that is least plausible. The most likely problem with perennial crops is perennial weeds. For sure they will suppress the annual weeds that require the destructive application of herbicides and regular ploughing. But long-lived crops will offer opportunities for longer-lived weeds to invade, particularly woody plants, and those are much harder for agricultural machinery to cope with. It only takes a small opening in a field of perennial crops: a wet hollow, or some blow-down from a strong wind, and it will quickly be filled with a birch sapling. I hope that the trials and expanded production that Monbiot envisages will still take place but I can foresee many hurdles in the way of perennial crops as a panacea.

Alongside these practical considerations there is one notable omertà that challenges Monbiot’s remedy. He implicitly assumes, by necessity, that the human population is a fixed term in the equation. It is of course possible to feed all the people currently on the planet on less land than we currently use, and we could do so more fairly and effectively using the approaches he advocates for. But can we assume that falling birth rates and the demographic transition will keep the problem within manageable parameters?

Moving into this area is fraught with moral peril and I don’t blame Monbiot for evading the issue. Personally I refuse to be drawn on the question of what a correct or sustainable human population might be. The answer depends on assumptions or ethical principles that are not widely agreed upon and all of which, once allowed to play out, lead to problematic outcomes. It’s not a question that science alone can answer. Nevertheless there is a simple truth which is that a growing population will, on average, lead to greater impacts, even if temporarily dampened by reduced inequality of consumption. A shrinking population raises further questions as to whose numbers are declining and why. The process is unlikely to be consensual and more plausibly involves mass suffering. Such are the grim repercussions of getting the equation wrong.

The danger of treating human population as a static term is well-illustrated by the example of the Green Revolution of the 1960s, when new crop strains and production techniques boosted yields worldwide. If the global population had remained at 1960 levels (around 3 billion people) then we would already be living in Monbiot’s world, one in which intensive agriculture could amply meet the needs of the majority while leaving land aside for nature. Understanding why this did not happen is the key to making sure the next agricultural revolution doesn’t amplify the results of the last. Would we merely defer the problem for another two generations?

Despite my concerns, I am happy to promote Monbiot’s solutions because they are undoubtedly better than the status quo and would buy us time to collectively agree upon what a sustainable future for the planet looks like. We can only begin to solve a problem once we dare to name it, and Monbiot has made every effort to consult not only the scientific evidence but the practical experience of the farmers who know what it takes to turn dirt into food. There is no silver bullet, only hard choices, and it is our responsibility to make them in the fairest, most equitable way we can.