New research from the University of Surrey in the UK and the University of Aberdeen in Scotland finds that vertical farming has the potential to meet growing demand for fresh produce while also delivering significant environmental benefits.
The study, which focused on vertical lettuce farms in the UK, showed that the method can produce lettuce with the same carbon footprint as traditional field farming, while using 28 times less land.
The study suggests that shifting all UK lettuce production to vertical farming could save around 8,000 hectares of farmland – a significant finding as the country grapples with land scarcity and the need for sustainable methods of food production.
“Our findings show that vertical farms can help reduce the climate impact of agriculture, especially if the electricity comes from renewable sources,” said co-author Zoe M. Harris, a senior lecturer at the University of Surrey's Centre for Environment and Sustainability.
Move up
The research team conducted a comprehensive life cycle assessment of a commercial vertical farm, examining the environmental impacts from the delivery of inputs to the farm, through cultivation, harvesting and delivery of the lettuce to its point of use in the restaurant market.
Studies have revealed that the farm emits 740 grams of CO2 per kilogram of lettuce – the same amount as conventional farming. However, because vertical farms can operate in urban areas, transportation emissions are significantly reduced, further enhancing their sustainability profile.
In their study, researchers found that around 40% of a vertical farm's total climate change impact comes from electricity usage, highlighting the importance of the energy source: running on renewable energy reduces carbon emissions significantly.
For example, if a vertical farm used the current UK electricity average grid mix, its climate impact would increase by around six times.
Michael Gargallo, a researcher involved in the study, noted that the materials used in vertical farming also play a significant role in the environmental impact, particularly the burlap plugs used to germinate seeds, which accounted for 18% of the farm's overall climate change impact.
Gargallo suggested that vertical farms could be made more sustainable by researching alternative materials such as coconut fiber and perlite. “Using different materials could make vertical farms even more sustainable. Future research should look at alternatives such as coconut fiber, hemp and perlite,” he noted.
Farm of the Future
Vertical farms employ methods such as hydroponics, which nourishes plants with nutrient-rich water instead of soil, and use advanced technology to grow crops in controlled environments.
This innovation not only conserves land and water but also enables crops to be produced all year round, addressing food security challenges exacerbated by climate change and urbanization.
The study authors also looked at other environmental impacts, such as water use and pollution. Vertical farming systems can use up to 90% less water than traditional farming due to a closed-loop recycling system.
The researchers emphasized that while vertical farming has a lower overall impact on climate change, there is still room for improvement, particularly in reducing the environmental burden associated with waste management.
In terms of waste management, the impact of different disposal methods for non-recyclable waste generated by vertical farms was evaluated: incineration, anaerobic digestion and industrial composting were considered, with findings indicating that incineration has a relatively low impact on climate change compared to other methods.
However, the potential for energy recovery and compost production through anaerobic digestion and composting makes them attractive options for increasing the sustainability of vertical farming.
With the world’s population expected to reach nearly 11 billion by 2100, sustainable agricultural solutions are becoming extremely urgent. The UK currently imports a significant proportion of its vegetables and relies on foreign sources, which leads to increased transport emissions.
By adopting vertical farming, the UK could boost local food production, reduce reliance on imports and provide consumers with fresher produce.
Promising Practices
The findings come at a pivotal time for food and beverage manufacturers looking to adapt to changing consumer preferences and regulatory pressures: vertical farming is a promising way to ensure a steady supply of fresh produce while reducing the environmental impact.
Growing crops closer to urban centres not only minimises transportation emissions but also meets growing consumer demand for locally grown products.
Harris concluded: “Despite the limited scope of available data, our study is an important first step towards demonstrating that vertical farming is more environmentally friendly than previously thought. Findings from this study may inspire further investigation into the potential for vertical farming to transform the food industry.”