I don’t remember a lot of my college chemistry classes, but I do recall the professor stressing that you can’t make something out of nothing. Or as he put it, “there is no such thing as a free lunch.”
Proponents, and their allies in the media, seem to assume that lab-grown meats will inherently come with less environmental impact than meat from animals. These assumptions, however, lack any data to back them up, in part because no one has yet developed a commercial-scale process for evaluation. Also, they are not anxious to share the details of their processes, including raw-material inputs, energy inputs and waste products such as greenhouse gas (GHG) emissions.
In conventional beef production, sunlight represents a primary input, allowing forage plants to create biomass, which cattle use to grow and produce beef. Cattle, of course, also produce waste products such as manure and urine, which are recycled into plant nutrients. Cattle also produce GHGs such as methane and CO2, but at lower levels than typically cited in the media. (See a summary of the latest life-cycle analysis of beef production.)
Cultured muscle cells also require raw materials or feedstock to provide the carbohydrates, amino acids and other nutrients cells need to grow and reproduce (Remember: No free lunch). They’ll also require energy and water, and will create their own GHG emissions. So far, we don’t really know how much feedstock or what commodities will be used in these processes, but it probably will not be native hay. We also do not know what level of energy inputs these processes will require, or what waste products will result.
However, results of a new study from the LEAP (Livestock, Environment and People) program at the Oxford Martin School at the University of Oxford suggest that CO2 emissions from lab-grown meat cultures could exceed those from conventional livestock production. Cattle probably produce more methane, which is considered a powerful GHG, but CO2 persists much longer in the atmosphere, and thus, cultured meat cells could over the long-term, contribute more to global warming than conventional meat production.
Published in Frontiers in Sustainable Food Systems, the Oxford findings highlight that the climate impact of cultured meat production will depend on its energy demands and the availability of low-carbon energy sources.
“There has been a great deal of public interest in cultured meat recently, and many articles highlight the potential for substituting cattle beef with cultured meat to provide an important climate benefit,” explains lead author Dr John Lynch. “We show that it is not yet clear whether this is the case, partly because of uncertainties about how cultured meat would be produced at scale.” Lynch concludes, “The climate impacts of cultured meat production will depend on what level of sustainable energy generation can be achieved, as well as the efficiency of future culture processes.”
Someday, production of cultured muscle tissue might become more efficient and more environmentally friendly than animal-based meat production. The processes likely will involve some tradeoffs, sacrificing some efficiencies to gain others. Cattle production capitalizes on several efficiencies that require consideration as we weight those tradeoffs. Forage plants capture sunlight to produce biomass, which cattle convert to beef, milk and numerous useful byproducts. Forages often grow on land unsuitable for production of crops for human foods, and cattle also convert by-products such as distillers’ grains, corn stubble, wheat straw, oilseed meal and others into beef.
So when people tell you cultured muscle tissue will be “greener” or produce lower GHG emissions than conventional meat production, ask for proof. They base their opinions on a series of unproven assumptions, and typically forget those cultures require inputs. Cells don’t grow out of thin air. There is no such thing as a free lunch.