This post is part of a series from the TED 2009 conference held in Long Beach, California from February 4-8th. You can read other posts in the series here, and the TED site will release video from the talk in the coming weeks or months. Because I’m putting these posts together very quickly, I will get things wrong, will misspell names and bungle details. Please feel free to use the comments thread on this post to offer corrections. You may also want to follow the conference via Twitter or through other blogs tagged as TED2009 on Technorati.
Dickson Despommier wants us to think vertical, because we don’t have enough space to grow our food.
The agricultural footprint of 7 billion people requires a South America-sized plot of arable land to feed us, at current technologies. By 2050, we’ll have 3 billion more people, and we’ll need another Brazil’s worth of land. And we don’t have it. We’re farming 80% of all arable land on the planet, and we’re doing so at great cost.
We use 70% of our fresh water and 20% of fossil fuels to produce our crops. We use massive amounts of fertilizes, pesticides and herbicides. This leads to agricultural runoff and dead zones. We’re killing off native vegetation in these dead zones, which helps explain why there have been three “millenium” floods in New Orleans in the past couple of decades.
The radical idea Despommier is putting forward is this: “What if we didn’t need soil?” We know how to do this, he tells us, using hydroponics, aeroponics, and drip irrigation. We used these techniques to raise produce in the South Pacific duing World War II… then promptly forgot what we learned.
Why vertical farming? There’s no run-off, we can produce crops year-round, we don’t lose crops to severe weather, and we use fewer fossil fuels, because there’s no plowing.
What if we built cities around sustainable, vertical agriculture? We’d build sustainable eco-cities, recycling water from urine, making power from solid waste. Despommier argues that all this technology exists already, and just requires the ambition, bravery and creativity to put them into place.
I’m not entirely sold that this solves land usage problems. These vertical farms use sunlight, not artificial lighting, right (if they do use artificial lighting, then the question of where that energy is coming from comes up)? That means you can’t nest these things closer together than they are tall, adjusted for latitude, since the crops won’t grow as well in shadow. For a large battery of these things, your vertical farm/traditional farm yeild ratio is going to look far less attractive (although probably still over unity), since you will have to account for shadowed “dead space” where you can’t put the towers.
Also, you won’t be able to put the towers near other tall buildings. This will pose interesting zoning questions.
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I heard about this concept this summer. I too was a bit taken aback at first, as there are some obvious issues, such as lighting. However, when examining the concept more carefully, doing some hw, it seems like a pretty dynamic idea. It does not have to be so tall as to block out sunlight from neighboring farms/buildings. You can supplement natural light with some artificial light (possibly powered by solar energy captured in parts of the building that cannot otherwise get to the crops, or other renewables). And I do not think you would clump them all together. It would make sense to spread them throughout the city and suburbs to create a truly local food source. It sounds like a great idea, and though Despommier seems a bit whimsical, he has partnered with some pretty well established companies and groups. I am excited to see one of these go up!
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You might be interested to learn that there are now 7 operational vertical farms with many more on the way. Japan, Korea, Singapore, England, USA, Sweden. When I spoke in Long Beach, there were none! Perhaps they will post my TED talk when there are hundreds!!!