How Sustainable is Vertical Farming? Columbia Students Try to Answer the Question
By Renee Cho
The world’s food system is beginning to strain under a global population expected to reach nine billion by 2050, by which time the planet’s arable land is projected to be half of what it was in the 1970s. And as climate change threatens long-term food security, agriculture will need to produce 70 percent more food to feed an increasingly crowded world.
Today’s agricultural systems are not as efficient or sustainable as they should or could be: Agriculture uses 80 percent of freshwater and produces approximately 24 percent of the world’s greenhouse gas emissions; pesticide use causes runoff that pollutes rivers, lakes and oceans.
Moreover, the average item of food travels approximately 1,500 miles before it reaches our plates, resulting in wasted food and more greenhouse gas emissions.
Vertical farming—the growing of crops (up rather than out) in a closed stacked system— is one promising solution to the drawbacks of traditional agriculture. Compared to traditional agriculture, vertical farming uses 70 to 95 percent less water and over 90 percent less land, while harvesting 80 percent more per unit of area. The Association for Vertical Farming, a two-year-old nonprofit focused on advancing the industry, says that vertical farming allows farmers to produce crops all year round because all environmental factors are controlled. It produces healthier and higher yields faster than traditional agriculture, and is resilient to climate change. Moreover as the global population becomes more urbanized, vertical farms can help meet the rising demand for fresh local produce.
There are many kinds of vertical farms, differing in the type and square footage of buildings or rooftops they occupy and the mode of light used (daylight or LEDs). Crops can be grown using hydroponics, in water or a growing medium with nutrients delivered directly to their roots; aeroponics, where a mist delivers nutrients to plant roots; aquaponics, when fish are raised concurrently and their waste is used as nutrients for crops; or even in soil if the building is designed accordingly.
The 109-member, Munich-based Association for Vertical Farming challenged a group of students in Columbia University’s Master of Science in Sustainability Management program, who must work in teams with real clients for their final capstone projects, to come up with a certification system to assess the sustainability of vertical farms. Ideally, the certification system would be able to define the criteria for a credits-based sustainability rating of farms, recognize farms operating sustainably, and provide a best practices guide for existing and new farms to become more sustainable.
“The challenge The Association for Vertical Farming is facing is how do you manage the growing industry of vertical farming,” said Kiley Miller, one of the project’s student managers. “As that growth continues, you need to make sure that these operations are sustainable, and not impacting water resources and energy use. There’s a lot of focus on food as a sustainable piece, but not as much on entire farming systems, and operations and management structures. So The Association for Vertical Farming is trying to figure out a way to standardize systems performance across the industry and within the farms, and to identify best practices and benchmarking baselines so it can engage with these farms and ask how can we improve, how can the industry improve as a whole.”