The climate impact and land use of cultivated meat: Evaluating agricultural feedstock production

forests, wetlands, or savannas. When these ecosystems are altered or converted, for instance into crop fields or pastures, the carbon that could have been sequestered by the native vegeta- tion is a forgone benefit and therefore must be considered as an opportunity cost when quanti- fying the climate impact of a food product [104]. Searchinger et al. (2018) [68] suggest using the “carbon cost of consumption” (CCC) to evaluate the climate impact of food products. CCC is the sum of production emissions and car- bon opportunity cost of a consumed product. Most previous studies only focus on production emissions. By factoring in carbon opportunity cost, we can quantify the climate impact of not only the production emissions from agriculture, but also the forgone benefit of native vegeta- tion. This is especially relevant when comparing conventional animal agriculture with alterna- tive food production methods like plant-based meat alternatives or CM, which potentially require less land and thereby incur lower carbon opportunity cost. Incorporating carbon opportunity cost into climate impact assessments offers a more nuanced and comprehensive understanding of the climate impact of food production systems, particularly highlighting the value of native vegetation for climate change mitigation [68, 105]. The foregone carbon sequestrations potential of arable land in Germany is assumed with 2.9 t CO2 ha-1 yr-1. Multiplying this factor with 44/12, which is the conversion factor from C to CO2 [106], and the land requirements results in the carbon opportunity cost per output. The sum

of total production emissions and carbon opportunity cost results in the carbon cost of con- sumption. Data for environmental impact of soy was taken from DonauSoja (2022) [107] and data of foregone carbon sequestration of arable land was taken from Fehrenbach & Bu¨rck (2022) [108]. 4. Results The analysis of CM production, factoring in energy consumption and land use, yields compel- ling insights. We have found that solar energy integration and land utilization, coupled with crop rotation restrictions, play a critical role in the sustainability and feasibility of CM. In the ensuing results and discussion section, we elaborate on these findings, positioning them in the context of the existing body of research. The crops’ share in the 100-hectare reference land area following linear optimization is shown in Fig 1. In terms of crop distribution, all four scenarios utilized soybeans with a maxi- mum cultivation area of 50 hectares. The cultivation of rapeseed was maximized within crop rotation limitations at 20 hectares for all scenarios. For wheat, scenario 1 had a cultivation area of 13.33 hectares, while scenario 2 had a cultivation area of 7.59 hectares. In contrast, scenarios 3 and 4 had a wheat cultivation area of 13.33 hectares and 8.75 hectares, respectively. For maize, scenario 1 had a cultivation area of 8.10 hectares and scenario 2 had a cultivation area of 9.63 hectares. In contrast, scenarios 3 and 4 have a cultivation area of 0 hectares for maize. Sunflower was cultivated at 13.33 hectares in scenarios 3 and 4 but was not cultivated in sce-

narios 1 and 2. Potato cultivation was 8.57 hectares for scenario 1, 7.04 hectares for scenario 2, and 3.33 hectares for scenarios 3 and 4. In terms of energy production, scenario 2 and 4 uti- lized solar panels with an area devoted to solar panels amounting to 5.74 hectares and 4.58 hectares, respectively. A comparison of different scenarios for CM production and traditional pork farming was conducted, presented in Table 7. We made use of the review by Gislason et al. (2023) [21] to compare scenario outcomes to pork production worldwide. The review analyzed 31 LCAs cal- culating land use efficiency for pork production. Boxplots for land use efficiency reported in CM LCAs, Gislason et al. (2023) [21] and the scenarios of this study are visualized in Fig 2. PLOS ONE Evaluating agricultural feedstock for cultivated meat PLOS ONE | https://doi.org/10.1371/journal.pone.0316480 January 22, 2025 15 / 27