Author Archives for Philip Proefrock and Hank Green
The inside of a skyscraper is, literally, the most expensive “land” in the world. So it probably isn’t the best place to grow our food.
The idea of vertical farming (growing food in high-rise buildings in the middle of cities instead of out on farms) has been gaining a lot of interest lately. Most recetly, it showed up on BoingBoing, one of our favorite blogs. We’ve seen a few of these proposals, and we’ve been following the concept for some time. It seems EcoGeeky enough, but a quick glance at the actual economics of farming shows that this isn’t ever going to work.
At first, it seems to make all the sense in the world. Moving production of food into population centers to eliminate shipping. Creating highly efficient “food factories” that allow land elsewhere to be freed from cultivation. But when you look at some of the practicalities behind constructing buildings like these, vertical farms make no sense. As the Vertical farm Project itself notes: “The Vertical Farm must be efficient (cheap to construct and safe to operate).” And a vertical farm is the opposite of efficiency.
A farmer can expect his land to be worth roughly $1 per square foot…if it’s good, fertile land. The owner of a skyscraper, on the other hand, can expect to pay more than 200 times that per square foot of his building. And that’s just the cost of construction. Factor in the costs of electricity to pump water throughout the thing and keep the plants bathed in artificial sunlight all day, and you’ve got an inefficient mess.
Just looking at those numbers, you need two things to happen in order for vertical farms to make sense. You need the price of food to increase 100 fold over today’s prices, and you need the productivity of vertical farms to increase 100 fold over traditional farms. Neither of those things will ever happen. And as much as I hate to burst bubbles, the main claim to the efficiency of vertical farms (the elimination of transportation costs) is not vaild. Even if most of the calories we consume were to be grown inside of cities, almost all of it would be shipped out for processing (most of the food we eat isn’t fresh veggies…you may have noticed.)
None of this is to say that we think farming will remain forever as it is today. EcoGeek is glad that there are many changes coming to agriculture, some of which will increase yields enough to keep prices low while feeding the 10 billion people the Earth will house by 2050. And with the right technologies, we should be able to do this without harming the Earth too much.
We’re not even saying that farms will remain outside. Building multi-level (not necessarily muti-story) automated farming units on inexpensive land within 100 km of food processing plants, for example, might make a lot of sense. But if you’re going to make farming more efficient, you aren’t going to do it by moving it into the most expensive land in the world.