The climate crisis is happening (as for some time already), and agriculture is a key protagonist. As elegantly explained by Nazim Gruda, professor at the Department of Horticultural Science of Bonn University: “Agriculture/horticulture and climate change have a dual interaction. On the one hand, the environment is affected by activities associated with agricultural food production, which contributes to climate change; on the other, the impacts arising from such activities backfire by changing the environmental conditions, thus affecting agriculture and horticulture.”
by Michele Butturini
Vertical farming is often presented as a revolutionary agricultural system of manifold qualities. It sometimes happens to hear stories of vertical farming vaguely reminiscent of the mythical land of Cockaigne – where no effort was needed to get food since it was falling from the sky.
Will vertical farming break the curse, releasing agriculture from its unsustainable environmental burden?
To be sustainable, vertical farming has to prove itself capable of minimizing the emission of green-house gases, such as carbon dioxide (CO2), nitrous oxide (N2O) and methane (CH4), per kg of food produced. However, a sustainable food system is more than just low emissions of green-house gases. As reported by Tessa Naus, the HLPE definition of a sustainable food system is: “a food system that delivers food security and nutrition for all in such a way that the economic, social and environmental bases to generate food security and nutrition for future generations are not compromised”. Therefore, the challenge is far more complex than merely reducing green-house gases. In an interview from the book “Urban Greenhouses and the future of food”, Leo Marcelis, head of Horticulture and Product Physiology Chair Group at Wageningen University, suggests that vertical farming can address some of the urgent challenges posed by the climate crisis,“there’s the problem of growing enough fresh, high quality, sustainable food and making it available to the rapidly growing urban populations in our rapidly expanding cities. To answer this, we need ever-higher production rates, and our production has to be highly controlled. […] They (n.d.r. vertical farms) don’t need much space and are indoors, they are not dependent on solar lighting, they’re independent of outdoor conditions, and can produce 365 day a year.”
Meeting the growing demand of fresh produce from the city, is an essential challenge for the sustainable food system we are looking for. As observed by Nona Yehia, CEO at Vertical Harvest “by 2050, 80% of the world’s population will live in cities”. According to Leo Marcelis, vertical farms “can be placed in or near-by urban areas anywhere in the world. [..] you can pick the produce when needed and thereby improve shelf-life: at this moment many vegetables are simply thrown away because they have too short shelf-life”. Indeed, even if just a fraction of this food loss along the supply chain is due to its distribution, ultra-short supply chains could significantly reduce the global fruits and vegetables loss, currently at 42% of kcal wasted. Furthermore, there is evidence that indoor grown leafy vegetables can have a longer shelf life thanks to a higher antioxidant level. However, even if ultra-short supply chains have very little food-miles, they aren’t always necessarily the most sustainable choice. As reported by Nazim Gruda: “Tomatoes imported from Spain can have two to four times lower global warming potential than those produced locally under intense heating in Austria and in the UK”. Being part of a sustainable food systems also implies making efficient use of water and land, and that’s what vertical farming does better than both greenhouse and conventional agriculture. Thanks to the optimized growing condition and the recirculation of the nutrient solution, not just water, but also fertilizers have the highest use efficiency currently possible for an agricultural system. More in general, the overall use of agrochemicals could be minimized, since pesticides and herbicides are theoretically unnecessary.