Nous produisons maintenant plus de nourriture plus efficacement que jamais, et il y a beaucoup à faire pour une population humaine de 7 milliards. Mais cela a un coût drastique en termes de dégradation de l'environnement, et la prime n'atteint pas beaucoup de gens.

"Sustainable Food Production", une nouvelle introduction de l'Earth Institute de Columbia University Press, explore comment l'agriculture moderne peut être rendue plus respectueuse de l'environnement et économiquement juste. Avec une population qui atteindra peut-être 10 milliards d'ici 30 ans, le moment est venu de commencer, selon les auteurs.

L'auteur principal est l'écologiste Shahid Naeem, directeur du Earth Institute for Environmental Sustainability. Il a coécrit le livre avec d'anciens collègues de Columbia, Suzanne Lipton et Tiff van Huysen. J'ai parlé avec Naeem des systèmes alimentaires modernes et des perspectives de réformes.

En évaluant aujourd'hui, vous citez le romancier anglais du XIXe siècle Charles Dickens :"C'était le meilleur des temps, c'était le pire des temps, c'était l'âge de la sagesse, c'était l'âge de la folie." Où voulais-tu en venir ?

C'est la meilleure des époques car, il y a une quarantaine d'années, entre les famines récurrentes, la pollution galopante et la montée en puissance d'un arsenal nucléaire qui tue la planète, la pensée humaine a subi une transformation remarquable. Il n'en a pas fallu beaucoup - tout ce que nous avions à faire était de nous assurer que les profits de l'entreprise humaine ne se mesurent plus seulement en PIB ou en dollars, mais en amélioration de l'humanité et du monde vivant qui nous faisait vivre. Et bon sang, nous disposons aujourd'hui d'une technologie extraordinaire reposant sur des avancées scientifiques dans tous les domaines qui rendent la transition vers la durabilité environnementale facilement à notre portée. C'est vraiment l'âge de la sagesse. C'est pourtant la pire des époques, car en même temps que nous avons ce savoir-faire, la dette environnementale que nous avons contractée lors de nos excès des révolutions industrielle et verte nous a rattrapés. Oui, nous avons moins de faim et de violence, et une meilleure santé. Mais les inégalités sont à leur pire niveau, et la sécurité alimentaire, hydrique et énergétique est au plus bas. Ce n'est pas un monde qui s'effondre, mais c'est un monde fragile, avec un ou deux milliards de plus qui rejoindront la population d'ici 2050. Trop de gens et de gouvernements adoptent bêtement la peur et le protectionnisme. L'isolationnisme est le plus grand obstacle à la réalisation de la durabilité environnementale. Au milieu de l'extinction massive, du changement climatique et des maladies émergentes, il est difficile de résister à l'envie de se mettre la tête dans le sol. Donc, ce n'est ni le meilleur ni le pire des moments, mais un amalgame des deux.

La "révolution verte" de la fin du XXe siècle a modernisé l'agriculture et produit une abondance sans précédent. Ça s'est mal passé ?

Dès le départ, la révolution verte était antithétique à la durabilité environnementale. Il cherchait à augmenter considérablement l'ampleur et l'efficacité de la production, mais accordait peu d'attention au résultat humain. Beaucoup considèrent la fin des famines massives comme un résultat positif. Aucun problème avec ça. Mais les coûts environnementaux, sanitaires et sociaux étaient énormes. Les deux tiers du monde ont été transformés en une machine stressée fonctionnant à plein régime, comme une machine à vapeur surmenée avec des jauges dans le rouge et des rivets qui sautent. Les petits exploitants agricoles ont été déplacés au détriment des opérations à grande échelle qui ont favorisé les propriétaires terriens et les riches. Certaines des sociétés les plus puissantes de l'histoire sont les conglomérats agricoles mondiaux qui ont émergé de la révolution verte. Cela suggère que la principale ligne de fond était le profit, et non le bien-être social et naturel. La montée des inégalités économiques, les zones mortes océaniques dues au ruissellement agricole et bien plus encore peuvent être attribuées à l'agriculture industrielle. Je suis continuellement étonné de voir à quel point des personnes aussi incroyablement intelligentes, souvent passionnées par l'élimination de la faim dans le monde, ont si peu prêté attention à la biologie environnementale de base. Les écosystèmes naturels peuvent fonctionner pendant des dizaines de milliers d'années dans des limites opérationnelles sûres. Rain forests, boreal forests, grasslands, mangroves, and even deserts and tundra, are all super resilient unless faced with insurmountable extrinsic changes. Natural ecosystems should have been models for how to rejigger the world to feed a rising human population. That means maximizing diversity, minimizing waste, balancing production with stability, and making sure we can feed tomorrow's children. The Green Revolution built fast, cheap, simplified, unstable systems, like the American muscle cars of the '60s and '70s, when it should have built high tech, finely tuned electric vehicles.

You discuss the "services" that the earth provides for us for free, but on which we don't place any economic value. Tell us about some of those.

The idea of "services" is a funny thing. It divides everything into providers and consumers. In our social systems, we know who the service providers are, and the providers know who the consumers are—they send us bills and if we don't pay up, we go to jail. Well, the largest service provider on Earth is the biosphere. It's spread out over the entirety of the world, from snail fish in the deepest ocean basins to microbes atop the highest mountains, and covering the sands of the driest deserts. It's 8.7 million species, numbering in the trillions of trillions of individual plants, animals, and microorganisms. They condition our air, water, and soil. The services are weird, like oxygen production—important not just for oxygen-breathing organisms such as ourselves, but for the production of stratospheric ozone that protects us from harmful UV radiation. There are other technical-sounding things like denitrification, nitrogen fixation, carbon sequestration and nutrient mineralization. Then there are more familiar services like pollination, protecting shorelines from wave surge, mitigating the spread of disease, and the mental health benefits of green spaces and the cultural values nature provides people. These services seem esoteric compared to the Internet, banking, electricity and education. Yet, they are critical to every facet of life on Earth. The "service providers," like plants, animals, and microorganisms, are sort of slave laborers. But of course, they don't really care a damn about us. They see us as just another species in the system. If they were sentient and could form an opinion, they would see us as moochers and freeloaders. If they could, they would probably send us massive monthly bills and, if we didn't pay up, send us to jail.

What are some sustainable practices we should be looking at?

Maximize diversity. We should outlaw monocultures. The Food and Agricultural Organization says that 75 percent of the world's food comes from just a dozen plant and five animal species. There are around 400,000 plant species, thousands of which are known to be edible. But for the large part, only 150 to 200 are used by humans. Ditto for animals. There are millions of species of animals, and the vast majority are edible, though many of the biggest, brawniest gun-toting beef eaters cower when we suggest they eat insects. In truth, unless we all become vegetarians or vegans, a number of studies suggest we may not be able to feed 10 billion by 2050. It's just that animals are handy sources of proteins when one's plant diet is of poor quality and starchy, as most grain-based diets are. Diet is complicated, but suffice it to say that, no matter how you look at it, by turning most of Earth into food production systems, the worst thing we continue to do is to focus on a handful of species. Nothing is more certain than the fact that the more diverse a system is, the more efficient and resilient it is. So why do we grow oil palm from horizon to horizon, or maize or rice or wheat? Moves to ancient grains, pasture-raised livestock, the diversification of crops, and better management of soil organisms, and, yes, even eating insects, are evidence that the world is catching on. If you're OK with GMOs, use these rather than herbicides, and make GMOs affordable to even the poorest farmers. Stop food wastage—40 percent of food is wasted. Use irrigation and use fertilizers optimally.

You say it is not just about producing food; it is about getting it equitably distributed, and achieving other humanitarian goals. Can you elaborate?

Sustainable food production is independent of social objectives. You can build a perfectly sustainable farm using slaves brutally abused by a despotic farm owner. But that's not what we want. What we want is food production to enhance human well-being, much the way the UN Sustainable Development Goals suggest—eliminate poverty, improve health, achieve universal education, and so on. We don't just want a sustainable world; we want a sustainable world we want. Easier said than done! In a way, the ecological part is the easiest:maximize efficiency and diversify. The social part is very challenging. A literature survey not long ago identified 800 different things people feel are important to human well being. They fall loosely under categories like health, trust in government, good social relations, and economic equality. And different peoples have different ideas about well-being. Food isn't just stuff in one's belly sufficient to get through one day, as the UN defines hunger. It's about sustaining a happy, rewarding life for one's self, one's family, one's country, and our increasingly global community.

Is "organic" food a scam?

There is absolutely no question that organic farming is environmentally friendlier. There is also absolutely no doubt that it can be less productive in many systems and almost assuredly much more expensive. Industrial agriculture, believe it or not, can be just as sustainable as organic agriculture. Here's the problem:Most of the world is living in or moving to urban environments, and most urbanites around the world are poor. Industrial agriculture produces food cheaply, and is the only food, in many cases, poor urbanites can afford. Organic farming becomes a scam if it presents itself as the only scheme that can secure adequate supplies of safe, nutritious food. Don't get me wrong—my little vegetable garden in the country is organic, and I buy organic—but current markets are not designed to address issues of availability and accessibility. The natural science underpinning organic farming is sound, but as a solution to environmentally sustainable food, it needs to address a huge array of social impediments.

Is there anything individuals can do to make food production more sustainable?

OH MON DIEU! There's so much one can do individually. Simple things like minimizing waste, paying the premium for sustainably produced food, maximizing the diversity of things one eats, reducing meat consumption. Don't buy any food that has oil palm products in it. Go to farmers' markets. Most importantly, just be cognizant of what an ecologically and socially complex thing food is, and what an amazing enterprise it is that we produce billions of calories every day. Humans do a lot of amazing things, but nothing is as stunning as the way we produce food. What we need to do now is to get back on track to producing it an in environmentally sustainable way.