Lab-grown meat is claimed to be the sustainable future of meat. This illuminating study suggests otherwise.
A recent study by researchers at the University of Oxford suggests that lab-grown meat may cause more environmental damage than real beef.
They predicted and compared the greenhouse gas emissions and resultant warming impact of cattle farming and lab-grown meat(1).
The study reports that whilst beef production causes more global warming in the short term, this effect decreases and stabilises, whereas lab-grown meat causes more persistent warming. Therefore, in some cases, cattle farming may actually cause less warming in the long-term. They say it is all about the different impacts of methane and carbon dioxide (CO2) emissions(1).
Meat consumption is a major driver of climate change. In fact, livestock production is estimated to account for 14.5% of human-generated greenhouse gas emissions(2). Cows are responsible for most of these emissions, with beef and milk production accounting for 41% and 20%, respectively(2). Our taste for meat also drives deforestation, biodiversity losses and requires lots of water(2). Livestock use an estimated 40% of farmable land and eat one third of cereal crops (e.g. wheat, rice) that are produced globally(3).
As we become more aware of meat’s environmental impact, plant-based diets and plant-based meat-alternatives such as Quorn or Beyond Meat are becoming increasingly popular. However, there is also increasing interest in cultured meat (also called lab-grown meat, cell-based meat or clean-meat) as the solution for environmentally friendly meat consumption.
So how is meat ‘grown’ in a Petri dish?
Cultured meat is made using tissue engineering techniques. It begins with taking stem cells from a live animal, which are unspecialised cells that can become different specialised cell types (Figure 1). In a bioreactor, a tank that provides perfect growth conditions, these stem cells are cultivated on a scaffold with a growth medium. The growth medium provides the nutrients needed to form numerous muscle cells (Figure 2). The scaffold provides a mould for the muscle cells to grow into 3D structures to mimic meat texture(4). They can be made of various materials such as gelatine, soy and even Lego.
In addition to fewer emissions, cultured meat may have further advantages, including fewer animal deaths, less antibiotic use and lower land and water requirements. Sounds perfect, right?
The type of gas matters
The current study compared the greenhouse gas emissions of three different cattle farming systems with four cultured meat production systems. These emissions footprints and the warming caused were compared under three meat consumption scenarios over the next 1,000 years using a climate model(1). This computer model simulates the interactions between different components of our climate (e.g. land, ocean and atmosphere).
The key aspect of the study is that it considered how different greenhouse gases behave. Most studies assessing cattle emissions convert other greenhouse gases to a carbon dioxide equivalent. This metric may poorly indicate the actual warming caused by emissions as some gases stay in the atmosphere for longer. For example, whilst methane, often associated with cow emissions, has a higher warming effect than CO2, it only stays in the atmosphere for approximately 12 years(1). Conversely, CO2 might persist and accumulate for thousands of years, potentially affecting the climate for much longer.
This is important because beef and cultured meat systems produce different greenhouse gases. Beef production produces all three gases that were looked at in the study – CO2, methane and nitrous oxide. However, cultured meat’s emissions are mainly CO2 associated with the energy required to power laboratories(1).
In one modelled scenario, meat consumption increased and then decreased to more sustainable levels. Here, beef production caused more warming initially, reaching a higher peak. It then decreased as consumption declined. Meanwhile, the warming impact of cultured meat continued to increase even when consumption decreased, due to the persistence of CO2 in the atmosphere.
In all modelled scenarios, because CO2 remained in the atmosphere for much longer than methane, cultured meat production might be just as harmful, and potentially worse, than cattle farming in the long-term.
It’s not that simple
Whilst this study provides valuable insights into the impacts of cultured meat, there are some limitations.
Firstly, it only assessed the impact of beef production on the climate. However, beef production also harms the environment in several other ways(2). Potential deforestation, water pollution, biodiversity loss and disease emergence risk need to be considered as cultured meat might perform better in these areas.
Furthermore, the study only used emissions data from three beef production systems (Sweden, Brazil and Midwestern USA)(1). As acknowledged in the study, the results are therefore not representative of global climate impacts as beef production varies between countries.
Additionally, the researchers had to use data from hypothetical cultured meat production methods, because currently no mass-produced commercial product exists(1). It is therefore important to remember that these predictions are slightly speculative.
Whilst the 1,000-year timeframe provides useful long-term predictions, it is difficult to accurately predict that far ahead. It is likely that production methods and technology will change in that time, possibly leading to lower emissions for both beef and cultured meat. So, while the results are still useful for the near to mid future, later predictions should be taken with a grain of salt.
So, no lab-grown meat in the future?
Despite its limitations, the study valuably demonstrates that, given the currently available data, it is unclear whether cultured meat is more sustainable than beef. It highlights the need to consider the type of greenhouse gas and its atmospheric lifespan to more accurately assess our climate impact. Currently, it looks unlikely that, in the near future, cultured meat will be the silver bullet against climate change that many hope for it to be; especially since consumers remain sceptic(5).
Nevertheless, it will be exciting to see if, or rather when, technological innovation makes cultured meat mainstream. The one thing that is clear is that our meat consumption needs to change; through improved cultured meat, meat alternatives or simply by following a plant-based diet.
1. Lynch J, Pierrehumbert R. Climate Impacts of Cultured Meat and Beef Cattle. Frontiers in Sustainable Food Systems. 2019;3.
2. Gerber P, Steinfeld H, Henderson B, Mottet A, Opio C, Dijkman J et al. Tackling climate change through livestock – A global assessment of emissions and mitigation opportunities. Rome: Food and Agriculture Organization of the United Nations (FAO); 2013.
3. Mottet A, de Haan C, Falcucci A, Tempio G, Opio C, Gerber P. Livestock: On our plates or eating at our table? A new analysis of the feed/food debate. Global Food Security. 2017;14:1-8.
4. Mattick C, Landis A, Allenby B, Genovese N. Anticipatory Life Cycle Analysis of In Vitro Biomass Cultivation for Cultured Meat Production in the United States. Environmental Science & Technology. 2015;49(19):11941-11949.
5. Bryant C, Barnett J. Consumer acceptance of cultured meat: A systematic review. Meat Science. 2018;143:8-17.