Interview with Dickson Despommier, Professor, Columbia University

despommier_2016Dickson Despommier / Wikipedia  

Are there vertical farms in practice now, or are they all in the concept / design phase?

No, there are no vertical farms in existence as we speak. This is now April 2009, but what there are lots of are high-tech greenhouses where massive amounts of produce are being raised. The best one I can think of is called Eurofresh. It's in the middle of the Arizona desert and it's 318 acres' worth of indoor farming in a place, which ecologically speaking you, could never farm. And the advantage of course is that you can control everything inside, so you can control the humidity and you can control the temperature, and as a result you can grow virtually anything you want.

In Deep Economy, Bill McKibben wrote about the need to rebuild local farming which will help cut down food transportation costs and inefficient uses of water and energy. In particular, McKibben highlights how organic farmers markets can bring healthy food to local areas while also rebuilding local communities damaged by big container stores and lower community engagement due to TV watching, etc. How can vertical farming support local communities?  How can they be integrated with existing farmers' markets?

Well, I think farmers' markets are a step in the right direction but the one thing they don't address, of course, is seasonality, so, if you think about farmers markets and green markets in the wintertime, what are you going to do?  And if it's not harvest time, then you're stuck and if you want to grow it locally that's fine, but if you live in let's say Portland, Maine, you've got a very short growing season and you've still got a lot of people that live in Portland, Maine. Minneapolis is another place that has great need for this but very little possibilities. So, I think if you could take a green area that's set aside for organic farming and enclose it so you can get year-around farming then you would solve part of the problem.

The second part of the problem is the amount of produce that you can supply. Green markets are great for those that take advantage of them, but if you take a city like New York where you have eight million people or even Washington, D.C., some two million people, I think the green markets don't go very far. What you have to do is expand the concept to integrate farming into the city proper, and I think that's where vertical farming, even if it's only two or three stories tall, allows that possibility. And in addition you can connect these ideas up with schools, hospitals or with rooftops of apartment houses or restaurants and you could now diversify your food supply. You can make it year-around. You can still grow these produces in ways which allows for complete control of the plant diets -- even organic farmers can't do that because they're still using soil.

Agreed that some soils are very, very suitable for farming. However, up to 1976 we used lead in our gasoline, and if you dig a core down into the soil almost of every city you'll find tons of lead. And if you start farming on those plots of land like say an abandoned apartment house that was torn down and now it's an empty lot and they say, "Well, nobody's using it so why don't we farm it?", and that's being done in some places, you run the health risks of including into your plants things that you really don't want. So, I think that indoor farming hydroponically and aeroponically offers the opportunity of complete and total control over what goes into that plant. And if you can convince the consumer that there's nothing unwanted in that tomato other than what should be there as a tomato, then I think you've got a big advantage over everybody else.

I've read about high-efficiency greenhouses designed in the Netherlands and now being built at Thanet Earth in the Isle of Kent, UK. The greenhouses in the UK are climate-controlled and monitored for performance. No soil is used. Plants are raised in troughs containing rock wool, an inert substrate. Are vertical farms just another form of high-efficiency farming?
Yeah, they are. In fact, if you could take the high-tech greenhouse iteration that now exists in the Arizona desert or in places  throughout England and the Netherlands and just stack them on top of each other, that's the concept. Now, tell that to an engineer and they'll just laugh at you because they realize that there's a lot of integration of systems that needs to go on here in order to get this to actually work. So you have water use issues. You have waste energy issues. You have then germination issues of where do you get your seeds from; how do you choose your seeds; how do you make sure that you don't introduce plant diseases indoors?

despommier_thanet2016Thanet Earth / Discover Thanet Earth  

Because an epidemic indoors is the same as an epidemic outdoors, the difference being, of course, outdoors your crop is destroyed and you have to wait until next year to plant again. Indoors, your crop is destroyed and you can do it the next day. You can go back the next day and start again. So, even there, there's an advantage and you're not going to avoid these issues, but they are much easier handled when you can control everything. So, the idea is yes, they are just simple, high-tech greenhouses that are now stacked on top of each other.
Water is consumed in vast quantities by large-scale industrial farms in the Midwest and western states. This model is now going overseas. How do you combat inefficiencies in water / land use for farming?  Why would vertical farms necessarily be more water efficient if developed at mass-scale?  How would water gains be quantified?

There are two things going on in a vertical farm or even in a high-tech greenhouse that are applicable to the water use issues. On a global scale 70 percent of the available liquid fresh water on the planet is used for irrigation. And once the irrigation is complete and the water the plants don't take up is then thrown away, it's contaminated with all those agri-chemicals that are necessary in order to make the plants grow in places where monocultures never existed. Remember farming is not a normal procedure in terms of ecological behavior. 15,000 years ago there weren't farms. Today, there are farms. What was there 15,000 years ago?  Hardwood forest, wetlands, grasslands, and today, we have replaced all of that of course. Now, we have to force the soil of those places to do the things that we want. In order to do that, we have to fertilize and we have to keep out the predators and the competitors, and that's what herbicides and pesticides are all about.  

Now, agricultural runoff is the world's largest source of pollution and that happens after the irrigated water is spread all over the fields. The plants take what they need and the rest of it is called run-off. Run-off has spoiled the world's estuaries. As the result, the United States has to import 80 percent of its seafood from other places because all of our estuaries are contaminated. To get back to the water issue though, hydroponic farming indoors uses 70 percent less water than outdoor irrigation, and another technology called aeroponics, which is a take-off on hydroponics in which the roots are actually sprayed with a thin film of water, uses approximately 70 percent less water than hydroponic farming. So, if we were to choose hydroponic farming for most of our crops, we could save a tremendous amount of fresh water. The other side to the coin, which is also good, is that because you're doing this indoors you can capture the water of evapotranspiration, which is what the plant puts into the air after it takes the nutrients out of the solution that it takes up by its roots. It's an open system in which water is taken up through the stems into the leaves and then out into the atmosphere. When you see these big thunderstorms over Iowa, all that water was put into the atmosphere by corn because they irrigated the corn and the leaves of the corn plants put that into the atmosphere.

despommier_hydroponic2016Hydroponic farm in Japan / Fast Company  

Now, if you're inside you can de-humidify the atmosphere and recapture that water. You could take gray water- you could have one of the buildings set aside to re-mediate gray water, and in that building, you're not going to eat those plants. You're going to use their ability to transevaporate, take gray water, which is black water that is municipal sludge and urine and feces. You're going to de-sludge it, use the gray water in that building, and let the plants transevaporate the water, collect it and re-drink the water. That's a living machine. Now you're connecting up the dots and you're saying, "Instead of behaving linearly in which I have a beginning, a middle and an end with waste, I'm going to behave in an ecological circle where there is no beginning and there is no end." The water just keeps re-circulating through this farm and the only thing that comes out is produce. You replace that much water with a little bit more water, but you don't have the water problems that you do now with traditional farming. So, hydroponic farming indoors in countries that are challenged for water, and I can name many of them, but you can think of all the Middle East, for instance, and many parts of Africa. Sub-Saharan Africa, for instance, is drought-stricken always. You put these farms in those areas and you will revitalize those areas.

How can efficient use of water in farming become widespread worldwide?  What kind of indigenous farming practices in countries like India, China, Viet Nam, all major rice or bread producers, can be highlighted as best practices?  Do you think widespread efficiencies will only arise once the realities of climate change take effect?

Well, the best motivator is to react against an impending doom. I'm afraid that's the way they always work and so crisis intervention is what human beings do best. We create the crisis of course, and then we find a way around it, or a way out of it. The climate change issue right now is not the fact that the climate is changing. It's that it's changing so rapidly, and the rapidity of the climate change is our fault. We do this by putting greenhouse gases in the atmosphere. Termites do this, too, but if you ever think of how much greenhouse gas is put into the atmosphere just by cattle--it's not just CO2 by the way. It's methane and they breathe out a huge amount of methane. It's a more efficient greenhouse gas than CO2, by the way.

What would a rural society like Viet Nam do with a concept such as indoor farming? In fact, I was in Viet Nam two years ago and I saw a lot of greenhouses in Viet Nam. It's how they germinate their plants. They take the germinated plant and then they move it outside. It's not a big step to imagine that if they just kept it indoors and built up from there. These are very adaptable societies: China, Japan, southeast Asia. These people are incredibly industrious and incredibly clever and we give them so little credit for having survived so long with such rich cultures. Go to a green market sometime and take a look at what they grow. It's amazing. It puts our green markets to shame. They've got about 400 different things there and we've got about ten and we think this is good, and their diets are so varied. It's quite amazing actually. So, to introduce vertical farming to a place like India, for instance, which I spent a month in last December and January. All I heard was the acceptance of this concept because--Why?  Because their monsoons are failing. They are up against the wall right now. For the first time in their history they had to import wheat. Where did they get it from do you think? Australia. I think this will be the next year and the second time in their history India will import wheat. They reached a tipping point. And then plant diseases play a big role in this as well, wheat diseases in India and throughout the Middle East, wheat rust, for instance. It's a terrible, terrible problem. It's a fungus. You can keep this fungus out of an indoor farm pretty easy, but it's very difficult to keep it out of the air.

You mentioned the potential use of vertical farms in developing countries. Would the cost of designing and creating the building make sense given the low cost of farm labor and the continued importance of small-scale farming to rural employment?  How would you convince policy makers in developing countries to support high-efficiency greenhouses or vertical farming?

When farming is succeeding in a country, I wouldn't pick those countries, but I would pick countries like Niger, Chad, Mali, Malawi, and other African countries where farming is failing. In fact, farming fails routinely in these places and you get mass starvation and there's no need for that. There's absolutely no need for it, so my take on wealth and the distribution of wealth is that the G8 or the G20 should pool their resources, and it's not going to take too much resources in this case. A couple of billion dollars here and a couple of billion dollars there isn't going to be skin off their nose, and for about a billion dollars you could jump start this project in about 20 different places as a prototype research facility. And the prototype research facility would then invent vertical farming for the region, and we've got some feelers out already from some places in case you're interested.

Jordan is one of those places. USAIDOPIC, and IFC have already been in touch with us and, in fact, the international branch of the USDA is also very interested in going to Jordan, because it's a friendly Arab country and it's got only five million people. They all live along the Jordan River. They spend 30 percent of their aquatic resources to make 3 percent of their GNP by exporting food. Now, if you look at their imports on the other hand, they import 80 percent of what they eat, but they still export food because they've got trade agreements to live up to so it doesn't make any sense at all. I'm not really very savvy with regards to these kinds of arrangements, but I know if they had a vertical farm research program ongoing at the University of Oman which was cosponsored by USAID and the USDA in which a team of experts were to partner up with a selected team-- And I would have some control in partnering up with, because I know some people already who want to be involved in this, and they include such large engineering companies as ArupFoster and PartnersFXFOWLE, and Grimshaw. These are companies that have a deep interest in getting involved in this movement, because they see it as a movement. They see this as the future of farming, basically, because when climate change does take hold in places where marginal farming exists now there will be no farming in another 20 to 40 years from now. Now, what are those people going to do?  I know if no alternative exists, they will migrate to some place where farming does exist. That's not their country. That's called invasion, as far as I can see. That's not going to hold up very well I think. So we want to stave this off. We want to prevent that. We want to enable. What I don't want to do is be the provider of food. I want to be the provider of how to grow your food.

What role do you see for the design professions (landscape architects, architects, urban planners) in creating these vertical farms?

Just go to our web site and look under the design section. What you have to realize is that none of those designs were actually solicited by us. These designs were submitted by people once they heard about the idea. They dropped what they were doing and created an image, which in their mind represents the way a vertical farm should look. Now, there is one called Eco-Laboratory by Weber Thompson. I don't want to get too specific, but I think I have to mention them because they are the only ones that actually called me up and said, "We're thinking of designing a vertical farm. What do you think it should look like?"  And I said, "Well, what I think it should look like is a prototype and it should be a research facility, certainly an applied research facility in which the scientists and technicians live together in an apartment complex adjacent to maybe a five-to-ten story building, which has all of the fittings necessary to try out whatever crops you're interested in growing. 

despommier_2016verticalfarmWeber Thompson /  

For systems integration, there is a group at MIT headed by Herbert Einstein. He's a civil engineer and he's got a team of his civil engineering graduate students working on this now, looking at ways of making sure that the water and the nutrient delivery systems and the plant monitoring systems, the planting, monitoring and harvesting of the crop, itself, are all integrated into a computer-generated series of controls. You could sit in an isolated room and monitor the way this whole thing is going. And it could be quite fantastic actually. It would be like looking at the way a nuclear power plant is managed but in this case there wouldn't be all these dangers of failure that you have imagined.

The management of water and waste are the big issues here and of course energy considerations are paramount, so design elements are necessary to take advantage of local passive energy sources, meaning, of course, geothermal would be my first choice, because that's something that everybody could gain access to simply by drilling into the ground, but it's expensive. If you have a lot of wind power, for instance, if you located these on the East Coast like they have in Washington, D.C., just outside the city limits, that would be an ideal setting. You've got the Potomac River and, at this point, it's tidal, so you've got water moving in both directions six hours a day, every six hours during the day and night. You could hook that up to a tidal power capturing system so that you could get part of your energy from tidal power, part from wind and part from solar, and then finally you could get a lot of it from the waste that's created by the harvest. Take a corn plant, for instance. You've got the roots, the stems, the leaves, the cob, the stalks. You don't eat any of that. You eat the kernels and that's all. That's about 5 percent of the weight of the whole plant. What do you do with the rest?  Well, I think you should plasma-gasify it. It's a technology which you may be familiar with, which actually vaporizes things back into their elements, and there are municipalities that are using that as a way of handling their solid waste management strategies.

Imagine a five-inch-diameter electrode and, then, now imagine two of them that are sort of angled into the middle of a chamber and a spark comes out, a permanent spark, and where it meets in the middle, it creates a plasma. If you measure the temperature of that plasma, it's hotter than the surface of the sun. Now, directing a spray of let's say, this table, for instance, or this rug, or your sweater, or that tomato that is rotting, or the stalks of a corn plant, if you were to particlize any of these up into small pieces, very small pieces now, microscopic, you can do this easily by dehydrating it and throwing it into a milling machine. You can make a fine powder. Then you make a slurry from the powder and you drive it right into the middle of this plasma and on the other side all you get is the elements and energy. The energy is used for two purposes. One is to run a machine. The other is to run anything else you want. It's about a 50 percent efficient system. Plasma gasification I like because it's a relatively new incineration technique that's absolutely clean. When I say absolutely clean, it's as clean as it gets to this point. There are still some caveats that they're working on but Port St. Lucie in Florida is already using it. The entire campus at MIT is using it so that's a very good endorsement for the technology. Steven Chu, U.S. Energy Secretary, actually likes it, also, so I think that he would be much in favor of seeing plasma gasification technologies developed, expanded, used and integrated into waste management strategies.

So, I think vertical farms could survive on their own without being part of the grid if they were to use strategies like that. Remember you get all your water back so there are huge advantages. You get your water, you get your food, you get your energy, and there's no storage, there's no shipping, there's no spoilage. There is none of these things. In fact, it's all vine-ripened. You don't have to pick it until you're ready to eat it. If it's not sold within six hours, it goes into the plasma gasification device. What could be simpler?  The closer your food gets to your plate, the simpler life gets so let's simplify. Simplifying is best so who's going to help us simplify?  I think landscape architects, outdoor architects.

There is a project in England called the Eden Project. It's got three superdome-sized geodesic domes that are surrounding a bunch of tropical plants which are kept there in order to create a safe haven for these plants, so that when their own environment recovers from whatever damage they're suffering from now, these plants can be reintroduced into those places. Now that's why it's called Eden. The entire structure is made out of ETFE, which is ethylene tetrafluoroethylene. It's a plastic film that's 1 percent the weight of glass. It's almost bullet proof, not quite. You can use layers of it and create insulation. You can make huge panels of this and it's as transparent as water so it lets in more light than glass. It does not create a greenhouse effect and it's a miracle material, and if you go to the Google Images and just type out ETFE you will see the swimming venue at the Beijing Olympics. That's made out of that material and it's built to last. This stuff doesn't go away, so I choose that as my starting building material. How you want to design it and how you want to make this work is up to the designers and architects.

despommier_olympics2016Example of ETFE use in the Beijing Olympics swimming stadium / Wikipedia  

Now, you can design mesh units for situations that require immediate intervention for food issues, like Darfur, for instance. For a natural disaster where you've had an earthquake, you can set up a lettuce farm instantly and, in six weeks, you could be producing lettuce and, in a month, you could be producing spinach and all kinds of other energy-rich foods that have lots of vitamins and minerals. You could be feeding people, in other words, within months after the disaster, and, in a year's time, you can certainly recover all of their nutrition based on these mobile vertical farms that could be set up any place, and you can use all of their wastes to recover water and energy. Now, you have no need for worrying about the spreading of diseases that are linked to contaminated water and this sort of thing and their food is safe. I think it offers a bright future for lots of different strategies.

Dickson D. Despommier, Ph.D, is Professor of Public Health in Environmental Sciences, and Micro-biology, at the School of Public Health, Columbia University. Professor Despommier is well-known for his work on parasitic diseases, and his recent conceptual work on Vertical Farming.

Interview conducted by Jared Green. 


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