Environmental implications of lettuce sourcing: Comparison of sourcing from vertical farms and conventional...

Today's globalised agricultural sector poses significant environmental challenges that are expected to worsen with population growth, increased urbanisation, and with the effects of climate change. In this context, vertical farming systems have gained traction as potential solutions to create a more resilient and sustainable food system. This study aims to evaluate the environmental performance of mixed salad bags from a conventional supply chain and compare it with that of mixed salad supplied by a large-scale vertical farm. Different locations for the vertical farm are also investigated. To compare the environmental impacts, life cycle assessment was conducted for various scenarios employing a cradle-to-grave perspective. The results suggest that the vertical-farmed supply can have lower environmental impacts compared to the conventional supply of mixed salad bags, e.g. having roughly 44 % lower CO₂-eq emissions. However, in five of the eight impact categories assessed, the vertical farm was found to have higher emissions, notably for resource use. Furthermore, it was found that the location of the vertical farm can play a critical role in its sustainability due to varying electricity mix compositions and transportation distances to final processing or consumers. Furthermore, the results are sensitive to the conventional supply data for comparisons. The findings contribute to the growing field of vertical farming and provide valuable information for transitioning toward a more sustainable food system.