In 2050 around ten billion people could live on earth. A large proportion of them are expected to cook with animal milk, eat cheese or meat. But how can all the cows, goats and sheep that are needed be kept without producing much more methane and further fueling the climate crisis? After all, the global food system is already responsible for up to 30 percent of all global greenhouse gases.
A newly published study in the specialist journal “PNAS” may have the answer. According to this, farmers can reduce the methane emissions of livestock with certain feeding and animal husbandry to such an extent that they can help to meet the 1.5 degree target by 2030. This was discovered by a research team led by scientist Claudia Arndt from the International Livestock Research Institute in Kenya’s capital, Nairobi. To do this, the researchers evaluated 430 studies.
According to the analysis, three strategies are promising for producing more milk or meat with less methane emissions: feeding the animals more overall, feeding them younger grass and mixing in more nutrient-rich concentrates. This increases the yield for farmers by an average of 17 percent, while methane emissions decrease by an average of 12 percent per kilo of meat produced or per liter of milk produced.
If, on the other hand, the aim is to reduce the daily methane emissions from livestock farming overall – and not just per kilo of meat or per liter of milk – according to the agricultural scientists, five feed additives can be considered: methane inhibitors such as 3-nitrooxypropanol, tannic green fodder such as clover, oilseeds, nitrates and oils and fats. With these additives, cows and other livestock would, on average, belch 21 percent less methane and give just as much milk or put on meat as without the additives.
Farmers around the world would need to use these feeding tricks on cows, goats and other ruminants to help meet the 1.5 degree limit by 2030. The authors of the study have also recognized that this is unlikely: “Europe, but probably not Africa, could make its contribution to the 1.5-degree target.”
According to the analysis, the feeding tricks come up against another limit: In livestock farming, they would fail to achieve the 1.5-degree target by 2050 and not just by 2030. Because the savings effects would probably fizzle out because the growing world population more and more meat and milk is starving—which drives up methane emissions from more cows, goats, and sheep.
Friedhelm Taube, Professor of Grassland, Forage Production and Organic Farming at the Christian-Albrechts-University in Kiel, has researched methane emissions in livestock farming on a test farm. He is partially critical of the study results: “More concentrated feed or more oilseed for cows would first have to be produced – and that would further reduce valuable arable land.” Since there is significantly more grassland than fertile arable land on earth, such additives would create unnecessary competition for land.
As far as methane inhibitors like 3-nitrooxypropanol are concerned, there simply aren’t enough studies to convincingly demonstrate their long-term benefits.
On the other hand, Taube sees a promising strategy for saving methane if cows can eat younger grass in the pasture. “Preserving easily digestible material for the animals and the grazing land also helps to bind the carbon in the soil, promote biodiversity and protect groundwater from further nitrate pollution.”
According to the agronomist, feeding cows more tannin-rich plants such as clover makes sense. “Nutrient-rich herbs and clover species can bloom on the forage areas over the summer and thus provide food for increasingly endangered wild bees and other pollinators, for example.”
All in all, studies on climate protection in livestock farming should not only look at the emissions balance, but also, according to Taube, take into account possible competition for land, species protection and animal welfare aspects.
Greenhouse gas emissions from agriculture and livestock farming are considered to be particularly difficult to avoid. In this way, mankind can say goodbye to coal, oil and gas to protect the climate and, for example, electrify cars, use heat pumps instead of oil heating or build wind turbines and solar systems. This saves CO2 that would be produced by burning fossil fuels.
When cows and sheep belch methane into the atmosphere or fertilized fields emit climate-damaging nitrous oxide, there are few ways to completely avoid these emissions. According to the findings of the Intergovernmental Panel on Climate Change (IPCC), these “residual emissions” must therefore be offset with negative emissions elsewhere, primarily through direct or indirect removal of CO2 from the atmosphere. This includes governments reforesting forests and rewetting bogs, as well as using costly air filtration systems to extract CO2 from the atmosphere.