Currently proposed types of lab-grown meat cannot provide a cure-all for the detrimental climate impacts of meat production without a large-scale transition to a decarbonised energy system, a new study has found.
The first-of-its-kind study from the LEAP (Livestock, Environment and People) programme, assessed the climate-change impact of several production methods for lab-grown and farmed beef accounting for the differing greenhouse gases produced. Their new projections reveal that replacing cattle with cultured meat may not be a simple replacement of high-impact with low-impact.
The study found that some projections for the uptake of particular forms of cultured meat could indeed be better for the climate, but others could actually lead to higher global temperatures in the long run. Published in Frontiers in Sustainable Food Systems, their 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. 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. An important issue in comparing farmed and cultured beef is that the different warming impacts of greenhouse gases are also not well accounted for in the standard measure used in carbon footprints.” explains lead author Dr John Lynch.
Agricultural greenhouse gas emissions are responsible for around a quarter of current global warming. Replacing conventional cattle farming with ’labriculture’ – meat grown in the lab using cell culture techniques – has been widely discussed as a way of reducing this environmental impact. But these estimates are based on carbon-dioxide equivalent footprints, which can be misleading because not all greenhouse gases generate the same amount of warming or have the same lifespan.
“Cattle are very emissions-intensive because they produce a large amount of methane from fermentation in their gut,” advises study co-author Raymond Pierrehumbert, Halley Professor of Physics at the University of Oxford. “Methane is an important greenhouse gas, but the way in which we generally describe methane emissions as ‘carbon dioxide equivalent’ amounts can be misleading because the two gases are very different. Per tonne emitted, methane has a much larger warming impact than carbon dioxide, however, it only remains in the atmosphere for about 12 years whereas carbon dioxide persists and accumulates for millennia. This means methane’s impact on long-term warming is not cumulative and is impacted greatly if emissions increase or decrease over time.”