Photo: Curbed SF, via SOA Architects via NYT
The 7 billionth person on earth was recently born. Population explosion is expected to continue, and it’s obvious the resources to maintain us are not adequate.
Demographers are predicting 9 billion people will occupy the planet by 2050, mostly in urban areas. One big question is how to feed them all. Urban areas are already the most difficult place to get fresh, local food.
The size of cultivated land feeding the world is currently about the size of Brazil. There is not that much more arable land available to serve billions more residents.
Vertical farming goals
One solution on the drawing board is vertical farming. Glass skyscrapers of hydroponically crops grown under elaborate lighting and heating systems are expected to serve hundreds of thousands of urban residents.
A controlled environment like this would:
- eliminate the need for pesticides
- allow natural predators to be introduced
- eliminate soil erosion
- eliminate runoff – water and pesticides
- reduce transportation costs and carbon emissions
- reduce spoilage
- allow year round production
Sounds ideal? I don’t think so. I have a lot of questions.
6 Concerns about vertical farming
Vertical gardens: cool idea, but is it really sustainable? There is a small greenhouse at the Amundsen-Scott Research Station in Antarctica that provides about one salad per person a day. The estimated cost of the vegetables they produce is about $50/pound, due to the necessary heating and lighting. That’s an extreme example, but I think it makes my point. Would renewable energy be financially viable? My research shows that a solar array would need more room than the actual skyscraper! (photo: Chris Jacobs courtesy the New York Times, via Curbed SF)
1) In the estimate of current arable land, has it been taken into consideration that much of that is for meat? How much of that land is actually for food that is to be produced vertically?
2) Vertical farming produces fruits, grains and vegetables. What about meat and dairy? How is that to be supplied?
3) Are locally appropriate crops to be grown? We should be eating what is in season in our locale for optimum health. In a controlled environment, just as shopping at a supermarket, we would not grow or eat locally. Mangos have no place in a Manhattan garden, for instance.
4) What is the cost of light and heat? Would that make the price of the food out of reach for the people it is supposed to serve?
5) Wouldn’t the cost of building a glass and steel skyscraper (billions, I imagine!) drive the price of food up as well?
6) Is the nutritional value of hydroponically grown food as high quality food grown in healthy soil?
Alternatives to vertical urban farming
I don’t think vertical farming is a good idea, but I do have some possible alternatives and solutions to the problem of feeding billions more people.
Erect single story greenhouses on existing rooftops in urban areas. There are already rooftop farms that are very successful. A greenhouse would extend the season, and year round production could be possible in some areas.
Add greenhouses on the outsides of existing skyscrapers, so the plants get adequate light. The need for new construction and expensive lighting is eliminated, keeping the purchase price reasonable.
Cultural solutions: eating habits and local economies
Change people’s eating habits to reduce or eliminate meat and include more plant-based meals. It takes 16 pounds of grain to make 1 pound of meat. By eating a vegetarian diet, the land we have would produce more food for more people. A lot of land is also planted with corn and soy to be used as fillers in processed food. Eating a diet of whole foods would eliminate the need for fillers, and edible crops could be grown.
Create a local economy and get people to eat, purchase and trade locally. Before you could buy food in a supermarket (yes, there was a time!), you had to trade your goods for goods you did not produce. For a truly sustainable economy, we need to go back to this idea. We need to decentralize and focus our lives close to home.
Reducing the growth of the upward curve of the world’s population trend line is the bottom line. This is the source of the problem. I wrote about this on my own blog – The Planet is Overpopulated.
Vertical farming, to me, is almost science fiction. It’s so far removed from nature, it’s a fantasy and far from where we need to be moving to be self-sufficient.
About Nan Fischer
I am working on my masters in public health and have researched urban farming models as a food system solution. You make good points about the percentage of agriculture land devoted to livestock production but I think you should know of some concerns about the alternative solution you offer. Rooftop greenhouses would not be able to utilize economies of scale. Vertical farms have a highly sophisticated technological component that just isn’t feasible for every rooftop. Also, in order to prevent the introduction of harmful microbes, a vertical farm requires a clean room which again is cost prohibitive and difficult to regulate on a small scale. Another issue is the difficulties in distributing when sourcing is spread out.
Yes, vertical farming is more expensive than the methods currently used but those methods don’t include all of the external costs of our food system that aren’t calculated presently but probably will be in the future.
Thanks for your input, Kate! I wasn’t suggesting vertical farms on rooftops. The idea was for single story greenhouses to eliminate the need for so much lighting for a multi-story skyscraper.
I imagine 50+ years down the road, long after I’m gone, maybe vertical farming will be the only choice. The cost and energy obstacles may have been worked out by then, but for right now, it’s not a cost effective way to feed people.
Thank you for your prompt response. I would like to point out to you some variables that bring down the costs of vertical farming substantially. In fact, the price is so comparable to traditionally sourced food that a vertical farm in my area that is being built has informed the head of the local school superintendent that he can supply the school system produce for the same cost as their current supplier. This is something I’ve been brokering in my spare time. The way this farm can do this is that it can produce multiple yields in a year, the controlled environment makes crop loss from droughts or flooding a non-issue and he is building his complex into the ground which is a natural source of insulation. Lighting technology has evolved and reduced in price so much that this cost has been significantly reduced as well.
By the way, please check out the working farm in Korea called Suwon to show that this is being done if you are interested. It truly seems to be a solution to me but if you have other doubts I would love to hear about them.
Thank you for your time.
My main concern is the cost of energy to produce food year round. This seems to be common knowledge in the field. In the article about Suwon (http://www.spiegel.de/international/zeitgeist/0,1518,775754,00.html), it says:
“The main problem is light — in particular, the fact that sunlight has to be replaced by LEDs. According to Cox’s calculations, if you wanted to replace all of the wheat cultivation in the US for an entire year using vertical farming, you would need eight times the amount of electricity generated by all the power plants in the US over a single year — and that’s just for powering the lighting.
It gets even more difficult if you intend to rely exclusively on renewable energies to supply this power, as Despommier hopes to do. At the moment, renewable energy sources only generate about 2 percent of all power in the US. Accordingly, the sector would have to be expanded 400-fold to create enough energy to illuminate indoor wheat crops for an entire year. Despommier seems to have fallen in love with an idea, Cox says, without considering the difficulties of its actual implementation.”
I don’t understand how being able to grow and sell year round would offset the insanely high cost of lighting and heating.
Also, as I stated in my own questions in the post, this is a way to produce vegetables, not meat or dairy. To feed a city, people are going to want animal products, but that is not addressed in this scenario. Ideas?
And I truly believe we are going to have to live within local economic systems in the very near future. Eating locally will be the only way to survive. I don’t know how vertical farming fits into that when you can grow non-local foods in an artificial environment.
My partner and I run a vegetable farm, and we barter vegetables for eggs, cheese, honey and bread, which is all local. Even the wheat is grown and milled in our town. We spend very little money on food, and, actually, are trying to get away from buying in a supermarket at all. Maybe this is a bias for me, this artificially lighted and heated food system.
But maybe, when urban sprawl has eaten up all the agricultural land, vertical farming will be the only way to bring food to anyone at all. I don’t know. If communities and cities supported small local farms, though, it would be feasible to feed the masses. If you think locally, you will find local food. Try buying from withing 40 miles of your home. It can be done.
In the future, though, I don’t know. I’m sure I won’t be around when it gets to that. In the meantime, I can only eat locally and support small farmers, getting away from the industrial food system.
Off topic, but it’s all tied together. Eating is the ONE thing we ALL have in common, so we need to work together to see that everyone is fed.
I thought of you last night as I attended a showing of the documentary The Greenhorns http://www.thegreenhorns.net/ at The Plant last night. it is about a new generation of young organic farmers trying to transform the future of farming. I also got to see 312 Aquaponics http://www.312ap.com/home/ which is a vertical farm occupying a portion of space at The Plant. According to one of the founders I spoke with they are currently developing a system at Loyola Marymount in addition to running their own system. I intend to find out more about their energy costs in the future. These models will certainly not take care of all our consumption needs but they are a viable source for getting more healthy produce in cities without the associated carbon footprints so please don’t write them off entirely!
As for the needs for meat, we will never be able to have a sustainable food system if we don’t reduce consumption of meat products. If meat prices included the externalities of their production people would be eating a great deal less which would actually benefit the health of society as a whole.
Local sourcing is gaining popularity in my area and there is a community trying to promote it aggressively. A man I know just started a local food guide for our area http://nwilfg.blogspot.com/2011/12/novemberdecember-nwi-local-food-news.html.
With farmers and promoters like you and your community we can help to move the food system in the right direction!