Of course we should produce as much food as possible—but not in ways that destroy the foundations of food production. Biodiversity is the foundation of plant production. If we destroy it, the fact that we used to have high yields won’t do us any good. The same thing applies to soil fertility and climate stability. If I burn a pile of straw, I’ll be nice and warm for a while, but after the straw has been burned up, I’ll feel cold pretty soon.

People often make the following simplistic argument: “If we were to do organic farming everywhere, we would produce less food. That’s why we need more space, so we’ll have to turn even the last nature reserve into farmland.” I hear this from people who haven’t paid any attention to market theory and who don’t know that altered prices change people’s consumption patterns. That applies especially to meat, whose production requires the largest proportion of land. The claim that “economies of scale” make it possible to produce more on large farms than on small ones is simply false. Today you can work more productively in smart small-scale farming than in a large agricultural enterprise. Between 50 and 70 percent of the world’s agricultural products are raised on farms that are smaller than two hectares. Especially in developing countries, farmers can cultivate small areas much more intensely than large-scale growers can. Industrial growers often force small farmers out of business and then use the land to raise fodder crops instead of food.

Yes, because the prices lie, and most of the real costs are being passed along to the general public or future generations. But we can’t afford to pursue social policies at the environment’s expense. It would be shortsighted to continue practicing agriculture the way we have done so far just to enable poor people to eat more meat. We would help poor people more if we stopped wasting 20 percent of our food on the way to the store and 30 percent more on the way to the consumer. Poor people are already suffering more than rich ones from the consequences of environmental damage.

If we start from the realization that our food budget is limited, we simply have to significantly reduce our meat consumption. A project in Denmark is demonstrating that this transition within a fixed cost framework actually works. The city of Copenhagen has ordered that 90 percent of the food served in all of its public canteens must be organic—and it has reached this target. The guests are well-fed, but less meat is being served and less food is being thrown away. As you can see, this discussion is not only about productivity.

We’d have to find out where the nutrient solution came from and how much energy was needed. This method might turn out to be more efficient than chicken breeding, and a chicken nugget might someday no longer cost €8,000.

All the same, I’m still skeptical—and I’m also skeptical about indoor production facilities where vegetables grow aseptically under artificial light. There’s a connection between the soil and the quality of the products that are grown in it. Winegrowers call it terroir. Human beings started to grow crops and breed animals 10,000 years ago, and since then we have continued to develop, together with our foods. Never before has our diet changed as much as it has in the last five decades. Many problems in our man-made environment have arisen because we have moved as far as we possibly could from natural relationships. So it might be wise to realign ourselves with natural systems and the ways they function.

Of course we have to reorganize agriculture in ways that enable it to cause less damage than it does today. For example, we shouldn’t accept the fact that today every pig is given antibiotics at least once in its life. We have to make sure that a chicken is once again treated like a chicken rather than a factory product. We need stable systems that do not constantly depend on external interventions. A small farmer in the Philippines who raises 90 different kinds of plants on one hectare has a completely stable system. We can learn a great deal from that.

That’s partly true. Agricultural engineering is in fact developing at a rapid pace, thanks to digitalization. I would wager that in 15 years we will no longer need any chemicals for removing weeds from our fields, thanks to improved mechanical methods. I’m personally very interested in this topic because of our cultivation of herbs and medicinal plants—they need to be raised in a completely weed-free environment. If you want to raise marigolds for skin care products, you don’t want to have poppies growing among them.

We must create underlying conditions that prohibit people from producing cheap products at the cost of the general welfare. Things are already moving in this direction: Sales of organically produced food are already growing year on year by as much as ten percent. And ten years ago you would probably not have been able to find enough families in Frankfurt to set up a vegetable-growing cooperative.