Skyscraper greenhouses could be farms of future

Story by Living on Earth. Listen to audio above for full interview.

More than half the people in the world today live in cities. True, but sad says scientist Dickson Despommier, because “In reality the city has assumed the role of a monstrous parasite when viewed from an ecological perspective.”

But that unflattering assessment doesn’t have to apply to cities in the future, according to Despommier. His book “The Vertical Farm: Feeding the World in the 21st Century,” predicts we’ll be growing crops hydroponically, without soil in high-rise buildings.

Despommier drew inspiration for the book from his students at Columbia University, where they worked to come up with an innovative way to make cities more sustainable. They came up with the vertical farm — a skyscraper of greenhouses.

Living on Earth’s Steve Curwood talked with Despommier about how vertical farms could help solve environmental problems associated with agriculture:

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.

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.

Read the full transcript on the Living on Earth website.

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Hosted by Steve Curwood, “Living on Earth” is an award-winning environmental news program that delves into the leading issues affecting the world we inhabit. 

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