19 Jun What does a life cycle assessment (LCA) of cultured meat tell us?
Life Cycle Assessment (LCA) is a systematic method used to evaluate the environmental impacts associated with a product, process, or activity throughout its life cycle. It is a comprehensive and quantitative approach that considers the environmental burdens and benefits at each stage of a product’s life, from the extraction of raw materials through production, use, and disposal.
In a recent LCA study (available as preprint) conducted at the University of California Davis, it was claimed that cultured meat could emit 4-25 times the amount of CO2 equivalent per kilogram of meat, than conventional meat production. This has resulted in a hot debate from authors of another recent LCA study for cultured meat, who claimed that cultured meat would be more environmentally sustainable. So, why are there such significant differences between these studies?
The primary reason is that no companies have really scaled cultured meat beyond bench or pilot scale and therefore the assumptions made around the method of manufacture vary and the requirement on the quality of input materials and facility design are imperfect. Examining the question of scale, the largest current operational facility is a pilot facility run by Upside Foods that has the capacity to produce approximately 22,680 kg of product per year. This equates to approximately 454 kg of product per week which is equivalent to less than the weight of 3 beef carcasses. Clearly, this is a long way from the scale of the US beef industry which produced 12.6 billion kg of red meat in 2021.
Both of these recent studies build on earlier LCA studies on cultured meat published by the Journal of Biotechnology and Bioengineering and CE Delft in 2021. The functional capacity of facilities modelled in these LCA studies varies from 10 million kg per year in one study, to 100 million kg and 122 million kg in the other two. One major difference in the comparison was the type of beef production system used. In the LCA assessment conducted by Sinke et al. (2023), comparisons were made based on the chicken, pork and beef production systems from Western Europe, whereas Risner et al. (2023) used data from US beef and dairy herds. These are both relatively intensive production systems whereas in many parts of South America and Asia-Pacific countries, ruminants graze native pasture and therefore have significantly different footprints.
An important assumption made by Sinke et al. (2023) is that cultured meat and conventional meat are equal, or in LCA terminology, the same functional unit was considered for both. However, at a nutritional level this is not correct, as cultured meat produced from a single cell type (e.g., muscle cells) will not contain key vitamins such as Vitamin A (which is fat soluble) or vitamin B12 (which is produced by bacteria in the gut of animals). No nutritional profiles for cultured meat have been published, so it is not clear what the levels of minerals such as iron, zinc or calcium will be in these products. It is expected that most cultured meat products will be hybrids with plant-based material and fortified with the above vitamins and minerals. What impact this will have on the bioavailability of these components is unknown.
It is interesting that in the LCA study conducted by Sinke et al. (2023), the environmental impact of buildings was not included, which given the nature of biotechnology facilities could be a significant source of any energy utilisation. The major conclusion from this report is that the carbon footprint of cultivated meat would be 44-92% lower than pork and beef and equivalent to chicken. However, this can only be achieved under the assumption that the energy source would be solar or wind-generated. What they did conclude, that agreed with the recent study from UC Davis is, that cultivated meat is a far more energy-intensive manufacturing process than conventional meat production, with 75% of this energy use attributed to cooling in the facilities, mostly during the large-scale growth stage.
In the recent study from UC Davis the need to remove endotoxin (bacterial lipopolysaccharides which can trigger a strong immune response in mammalian cells) from the cell-culture media was considered as a critical step due to its potential to impact on cell growth and human health, if retained in the final products. If these processes were not required, the Global Warming Potential (GWP) of cultivated meat production would be a lot closer to traditional meat production. This issue is therefore a major difference between these two reports. The final decision on endotoxin removal will sit with the various regulatory agencies, which will set limits for endotoxin in the final products. Major sources of endotoxin contamination can come from the water used or raw materials like amino acids and would be concentrated during the manufacturing phase. Cultured meat companies plan to use food-grade media for production due to the lower costs; however, this will result in greater variability in cell growth with potentially lower yields and higher scrap rates.
Other sustainability issues such as land and water utilisation, air pollution, acidification, and marine and freshwater eutrophication were also considered in the Sinke et al. (2023) study as an overall indicator of sustainability, however, energy demand was clearly the major issue. They concluded that cultured meat utilising renewable energy may increase energy demand by 58-616%, compared with a projected 2030 conventional meat production system that also uses renewable energy.
A relevant example of another emerging food production system is indoor vertical farming (IVF), which can offer valuable insights for the cultivated meat industry. In both IVF and the cultured meat sector, a significant portion of environmental impacts is attributed to energy inputs hence, any environmental impact assessment will be highly energy-source sensitive. As shown in an LCA study on IVF published in Sustainability, even minor changes in energy source selection can make a significant impact on the LCA outcomes of vertical farms.
Although research has demonstrated that transitioning to renewable energy sources could reduce running costs and the environmental footprint of IVF, the status appears far from promising. Despite the initial excitement in attracting venture capital, IVF companies now face a daunting road ahead as they confront a range of sustainability obstacles, most of them energy-related. Five prominent IVF companies have already halted operations or filed for bankruptcy in 2023 and the remaining companies represent a small fraction of the fresh food market, mostly affording to produce leafy vegetables and microgreens.
Cultivated meat will also be an energy-intensive process and will require the use of significant quantities of renewable energy to be less carbon-intensive than conventional meat production. In addition to the many technical and consumer acceptance challenges facing cultivated meat, the issue of sustainability will be critical, as it is one of the major drivers for the over $3 billion that has been invested in the technology. In countries like Singapore, which has the only commercially available cultivated meat product, access to renewable energy is minimal and this could be the case for many regions.
The key conclusion from the comparison of these studies is that it is challenging to conduct LCAs for technologies in their early stages of commercial development. The difficulty arises from the reliance on assumptions embedded within the models. With additional scaling of cultivated meat, the modelling of these production systems will improve, and we can expect to see refinements in the LCAs, including the incorporation of nutritional value.
This Thought for Food was written by Professor Paul Wood and Dr Mahya Tavan.
Photo by Firn from Canva Pro.