# Life Cycle Assessment of Land Use Trade-Offs in Indoor Vertical Farming +
## 3 Results and Discussion
### Environmental Footprint Results
By comparing the relative contribution of each process, most impact categories show a similar trend across both scenarios. The main difference is seen in LU, where Packaging accounts for a much larger share in the PV scenario (about 80%) compared to the GM scenario (around 39%). Although Cultivation maintains the main contributor in both cases, its percentage is lower in the PV scenario. This is because Cultivation is energy-intensive, and the PV scenario uses more renewable energy, which reduces its impact. As a result, \begin{table}
\begin{tabular}{l c c c} \hline
**Categories** & **Unit** & **GM** & **PV** \\ \hline Acidification (AC) & Mole of H+ eq. & \(4.85\times 10^{-2}\) & \(4.07\times 10^{-2}\) \\ Climate Change—total (CC) & kg CO2 eq. & \(7.11\times 10^{0}\) & \(5.20\times 10^{0}\) \\ Ecotoxicity, freshwater—total (EF) & CTUe & \(7.50\times 10^{1}\) & \(7.12\times 10^{1}\) \\ Eutrophication, freshwater (EuF) & kg P eq. & \(2.05\times 10^{-3}\) & \(1.79\times 10^{-3}\) \\ Eutrophication, marine (EuM) & kg N eq. & \(1.08\times 10^{-2}\) & \(9.06\times 10^{-3}\) \\ Eutrophication, terrestrial (EuT) & Mole of N eq. & \(1.21\times 10^{-1}\) & \(9.95\times 10^{-2}\) \\ Human toxicity, cancer—total (HTc) & CTUh & \(1.03\times 10^{-8}\) & \(9.14\times 10^{-9}\) \\ Human toxicity, non-cancer—total (HTnc) & CTUh & \(2.42\times 10^{-7}\) & \(2.24\times 10^{-7}\) \\ Ionizing radiation, human health (IR) & kBq U235 eq. & \(6.44\times 10^{-1}\) & \(5.44\times 10^{-1}\) \\ Land Use (LU) & Pt & \(1.15\times 10^{2}\) & \(5.70\times 10^{1}\) \\ Ozone depletion (OD) & kg CFC-11 eq. & \(3.83\times 10^{-7}\) & \(3.29\times 10^{-7}\) \\ Particulate matter (PM) & Disease incidences & \(3.68\times 10^{-7}\) & \(3.08\times 10^{-7}\) \\ Photochemical ozone formation, human health (POF) & kg NMVOC eq. & \(3.36\times 10^{-2}\) & \(2.71\times 10^{-2}\) \\ Resource use, fossils (RUf) & MJ & \(9.63\times 10^{1}\) & \(7.28\times 10^{1}\) \\ Resource use, mineral and metals (RUm) & kg Sb eq. & \(6.65\times 10^{-5}\) & \(5.98\times 10^{-5}\) \\ Water use (WU) & m\({}^{3}\) world equiv. & \(1.58\times 10^{1}\) & \(6.43\times 10^{0}\) \\ \hline \end{tabular}
\end{table} 
Table 1: Characterization results on the sixteen impact categories of EF v.3.1. with Cultivation contributing less, other processes like Packaging represent a higher share of the total impact in the PV scenario. The other impact categories where Cultivation was not the major contributor were Ozone Depletion (OD) and Resource Use, mineral and metals (RUm). Across both scenarios, OD was mainly affected by Packaging while RUm was predominantly influenced by Construction. In this study, the Packaging contribution to OD came from the production of polyethylene terephthalate. This result aligns with the observations of [PERSON] & [PERSON] (2018) [43], which indicate that ozone depletion, during plastic bag manufacturing, is strongly correlated with the production of low-density polyethylene and other polyethylene-based materials. On the other hand, the Construction phase contributed substantially to RUm due to the intensive material demands involved in setting up an IVF system. These systems, in fact, typically require large quantities of metals and high-tech materials for lighting, climate control, structural framing, and hydroponic equipment. This aligns with findings from [PERSON] et al. (2021) [44], who highlighted the construction of controlled environments as a major environmental hotspot due to the embodied impacts of materials and components. Due to its significance in these results, Cultivation was broken down into its main percentage contributions in Figure 3. Sub-processes contributing less than 1% in all categories, such as the production and use of trays and sensors, were excluded from the figure.