Professor Dickson Despommier worked with his students at Columbia University to come up with an innovative way to make cities more sustainable. They came up with the vertical farm — a skyscraper of greenhouses. LOE’s Steve Curwood talks with Despommier about how vertical farms could help solve environmental problems associated with agriculture.
GELLERMAN: You’re listening to a recycled edition of Living on Earth… I'm Bruce Gellerman. It’s official: more than half the people in the world live in cities. True, but sad says scientist Dickson Despommier.
DESPOMMIER: In reality the city has assumed the role of a monstrous parasite when viewed from an ecological perspective.
GELLERMAN: But that unflattering assessment doesn’t have to apply to cities in the future says Despommier. In his book “The Vertical Farm: Feeding the World in the 21st Century.” Despommier believes things will be looking up - literally - he predicts we’ll be growing crops hydroponically, without soil in high rise buildings.
Dickson Despommier drew inspiration for the book from his students at Columbia University. He spoke with Living on Earth’s Steve Curwood.
DESPOMMIER: A full class of students that didn’t want to hear anymore of gloom and doom about the environmental destruction that was going on outdoors - they said, ‘we want to work on something more positive.’ So I let them. I said, 'this is your money, this is your time, what would you like to do?' About a week later they came back to me and they said, ‘We think rooftop gardening in NYC would be a good idea.’ So, I said, ‘Great. Tell me how many acres of rooftops we’ve got, tell me which crops you would grow, and tell me how many people you can feed with 2,000 calories per day per person.’
They answered that question and they could feed about two percent of Manhattan only. So I said wait a minute, now don’t get discouraged here. Take your idea off the roof and move it into the building itself. Let’s talk about how many floors of a building you could actually do this in. That began the discussion.
Author Dickson Despommier. (Photo: Marlene Bloom)
CURWOOD: So if I were to be standing in front of a vertical farm, my eyes closed, and I open them - what would I see?
DESPOMMIER: Oh, you’d be amazed. You’d be absolutely amazed. First of all, you wouldn’t see the building, because all you would see would be the plants growing inside of a totally transparent building. It would look like the plants were being suspended in midair, and they were growing on…you couldn’t actually tell what they were growing on. And, in fact, they’re not growing in soil at all, they’re being grown hydroponically.
CURWOD: Where do you get the nutrients if you use hydroponics?
DESPOMMIER: So all you have to do is line up all the chemicals that plants need, and all the chemicals that humans need - which is about 6 more than plants need - and combine them together in the right ratios, dissolve them into water and feed them to your plants. Most people would cringe when they hear that for the first time, but no one would cringe if I told you it’s just like using MiracleGro on your plants. ‘Oh yeah, I understand that part.’
CURWOOD: How feasible do you think this is, Professor? I mean, what are the present examples of vertical farms?
DESPOMMIER: Well, there are none, as we speak. But I can almost guarantee you that within a year from now, there will be many. The country of Qatar has an enormous interest in this. China, India - they’re very interested in food security and food safety. They want food that’s produced by themselves, and if you live in Qatar, that’s not going to happen unless, somehow, you import all the soil.
Even then, you don’t have the right climate for all of this. So everything that they’re going to do has to be done indoors. If you go around the world and you say ‘where would vertical farming fit in beautifully into the needs of those places,’ you can find places like Iceland that have no soil, basically, whatsoever. They have six months of darkness, how can they possibly grow anything there? If you grow it indoors, and you use geothermal energy for your grow lights, the next thing you know you’ve got vertical farms going up.
CURWOOD: So in the vertical farm, how do you deal with the waste?
DESPOMMIER: Right! Well, we don’t call it that - we call it unrealized energy. Let’s take corn for an example. I would take that part we don’t eat. I would dry it down to completion, I would then powder it and I would run it through a device, which is currently in use throughout Japan called the plasma arc gassifier.
And what that does, is it takes any solid material and reduces it back to its elements. And what you get back from that device is the energy to run the device, first. You get no residual material that you have to worry about, and the last thing that you get back, which is much more important, is that you get some product produced by this process that you can then use in the form of a gas to burn and to create carbon dioxide water and heat. And the heat is then used to generate energy. The carbon dioxide and water can be fed right back into the vertical farm. It’s a closed-loop agricultural system, basically.
CURWOOD: Ok, today’s agriculture and new food movement is predicated on a couple of things - organic agriculture, locality and seasonality - what about thinking of June and strawberries, that sort of thing?
DESPOMMIER: I don’t blame you. I think I can’t argue against a fresh picked strawberry in the wild. I love wild strawberries, and people don’t even know what a wild strawberry looks like, most of them. People criticize hydroponically grown - artificial - they call it 'artificial food' - but I would just call it ‘indoor farming’.
They used to criticize a lot of the products produced by these farms because they didn’t taste good. They looked great, but when you got them to the table, they have nothing in common with the plants that you expected them to be. That was about ten or 15 years ago, and I think, once consumerism said, you know, ‘We don’t want plants that look good, we want plants that taste good,’ they went back and reexamined all of the qualities of plants.
They found out, very soon, that the reason why outdoor plants taste so good some years, but not every year, is because of the stresses that the plants have undergone during the growing season, particularly just before harvest. So to know what the characteristics of the plants are to begin with, means that you can control it.
CURWOOD: What do traditional farmers think of this idea?
A vertical farm that Dr. Despommier helped conceptualize with Eric Ellingsen. (Photo: Eric Ellingsen and Dr. Dickson Despommier.)
DESPOMMIER: You would expect I’d get a lot of hate mail. (Laughs). But I get a lot of curious mail from farmers who - they want to know about the ease of hydroponic farming. They want to know about the productivity of it. They want to know about the yields. A lot of them have seen the light, in the sense that - how many good years in a row do you think that a farmer gets? I don’t care where they live and I don’t care what crop they’re growing, if you have ten years in a row I’ll be willing to bet you that you don’t get more than four or five good years out of that. So they’re looking for alternatives, they’re curious, they’re not threatened at all by this.
CURWOOD: So where’s the natural connection to the land and the earth for people in this?
DESPOMMIER: Yeah. There’s no natural connection to the earth. And I must qualify that statement by saying that since farming is only 12,000 years old, and since we are, at least in terms of evolution, about 200,000 years old - farming is a really very recent addition to the human technology tool chest. And let’s say for instance that it’s not possible to address climate issues, the climate just keeps getting worse. You know what happens to farming?
For every degree of increase in the average temperature of the planet’s atmosphere, it’s estimated we lose about ten percent of the agriable land on this planet. If that continues up to five degrees, you can see the consequences would be horrible for an ever-increasing population of people unless we learn how to farm in another way. So the choices are almost zero. I think we have to address ‘how can a city live like an ecosystem?’ That’s the bottom line for this whole project, is to make food production at the center of an ecological behavior pattern, and make them imitate the balanced ecosystems that are still left.
GELLERMAN: Dickson Despommier teaches Environmental Health Sciences at Columbia University. His book is “The Vertical Farm: Feeding the World in the 21st Century.” He spoke with Living on Earth’s Steve Curwood.
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