Pathways to net-zero farming: a carbon footprint comparison of vertical versus traditional agriculture

F. Baumont de Oliveira, S. Bannon, L. Evans, L. Anderson, P. Myers, J.M.H. Thomas
Agriculture is one of the leading causes of climate change, contributing nearly a quarter of global greenhouse gas emissions. Indoor vertical plant farming (VPF) is a novel form of agriculture offering space savings, water efficiency, and hyper-local production. A significant caveat is the associated CO2 emissions from energy consumption. We conduct a carbon life-cycle analysis of lettuce production comparing imports from a Spanish field-based farm with hydrogen fuel cell-powered vertical farm in a UK context. We examine the implications of energy source trade-offs and the effects of deforestation. Experimental data using blue hydrogen energy shows emissions for VPF as 3.79 kg CO2e kg-1 without and 4.45 kg CO2e kg-1 with the impact of deforestation considered. Associated emissions for field-based imported lettuce are 1.14 kg CO2e 
kg-1 and 5.05 kg CO2e kg-1 without and with deforestation, respectively. Sensitivity analysis of energy sources in VPF shows tidal energy reduces emissions to 1.57 kg CO2e kg-1 with deforestation considered, a third of the emissions from conventional agriculture. Wind, tidal and geothermal energies also show promise for low carbon footprints. The results show that VPF with renewable energy sources could provide a lower carbon footprint than imported lettuce from a field-based farm. We believe this is the first attempt to make such a comparison based on real-world data from a VPF and consideration of the effects of deforestation.
Baumont de Oliveira, F., Bannon, S., Evans, L., Anderson, L., Myers, P. and Thomas, J.M.H. (2023). Pathways to net-zero farming: a carbon footprint comparison of vertical versus traditional agriculture. Acta Hortic. 1369, 125-132
DOI: 10.17660/ActaHortic.2023.1369.15
vertical plant farming, life cycle analysis, rewilding, renewable energy

Acta Horticulturae