Dickson Despommier, an advocate for vertical farming, asked “What if cities could function like an ecosystem?”, at the TED Mid Atlantic conference. Right now, cities are like a “black box, all these inputs go in and then out come wastes, which have to be removed.” In addition, current agriculture practices, which require the use of pesticides, fertilizers, herbicides and consume 70 percent of available freshwater and 20 percent of available fossil fuels, are unsustainable. Instead, Despommier argues, people must learn from nature and apply nature’s “grandest design” to cities: the ecosystem, embedding food production and waste reuse in the city’s systems.
Twelve thousand years ago, the earth had intact ecosystems. Among the earliest communities around the world, farming was taken up in many places around the same time. However, the environmental impact was minimal — there were only a million people. Now, a global population of 6.8 billion uses farm land the size of South America. This enormous growth is biologically-driven, argues Despommier. “Life is resilient. We are resilient. We have resisted ice ages, droughts, continental drift, sea level rise, diseases, and asteroids.”
Ecosystems live within their means. “The sun creates energy and everyone gets their share of that energy. That’s our only paycheck.” Using biomimcry, communities can harness solar power to create an urban ecosystem that could recycle and reuse all wastes. Vertical farms are a key component of this new eco-city model.
Within urban vertical farming structures, hydroponics, aeroponics and drip irrigation system can be used to create produce for urban populations at a rate “ten times more efficient that an outdoor acre of farmland.” Despommier thinks these vertical farms would have many benefits. There would be no runoff, no crop loss from extreme weather, and no cessation of farming due to weather. The systems would use 70 percent less water and no chemicals or fossil fuels. They would enable further urban densification and the repair of damaged ecosystems surrounding cities. Lastly, they could improve the health of inner-city communities and create new jobs.