A recent study conducted by the University of Surrey and the University of Aberdeen has shed new light on the environmental viability of vertical farming, particularly in the cultivation of lettuce. The research, which employed Life Cycle Assessment (LCA) using primary production data from a commercial vertical farm in the UK, provides a detailed analysis of the environmental impacts of vertical farming compared to traditional field-based methods. The findings suggest that vertical farming could be a greener alternative to conventional agriculture, significantly reducing land use and climate change impacts.
The study identified electricity requirements and the cultivation substrate as the primary environmental hotspots within the vertical farming system. Nearly 40% of the climate change impact from the vertical lettuce farm was attributed to electricity consumption, underscoring the importance of the energy source used. Remarkably, the research found that using renewable energy to power vertical farms could reduce climate change impacts by six-fold, bringing the overall emissions profile in line with traditional field-based lettuce cultivation.
Another significant finding was the land use efficiency of vertical farming. The study revealed that vertical farming requires about 28 times less land than traditional farming methods. If the UK replaced all its lettuce fields with vertical farms, it could save around 20,000 acres of land. This land-saving could be repurposed for other agricultural needs, offering a substantial environmental benefit.
Despite the promising results, the study highlighted areas where vertical farming could be improved to reduce its environmental impact further. One of the biggest challenges identified was the environmental cost associated with the jute plugs used to grow lettuce seeds. These plugs accounted for 18% of the impact of climate change and significant portions of water pollution and land use. To mitigate these impacts, the researchers suggest exploring alternative materials like coconut fiber, hemp, or perlite.
The study also pointed out that vertical farming systems could have a slightly higher environmental impact in categories like freshwater eutrophication potential and acidification potential compared to traditional farming. This indicates that while vertical farming offers significant benefits, it is not without its environmental trade-offs.
Dr. Zoe Harris, Senior Lecturer in Environment and Sustainability at the University of Surrey, emphasized the potential of vertical farming to reduce agriculture’s climate impact, particularly when powered by renewable energy. “Our findings show that vertical farms can help reduce the climate impact of farming, especially if their electricity comes from renewable sources,” she said.
As global population growth, urbanization, and climate change continue to strain traditional food supply chains, vertical farming offers a promising alternative. The study’s findings suggest that with suitable energy sources and materials, vertical farming can be a viable and environmentally friendly option for producing fresh produce. However, continued research and innovation are necessary to address the current challenges and fully realize the potential of this emerging agricultural method.
