Above photo: Cows graze in the shadow of the coal-fired Chalk Point Generating Station in Benedict, Maryland on May 29, 2014. Mark Wilson / Getty Images.
A new study highlights the risk of depending on soil carbon sequestration as a way to offset the emissions produced from raising livestock.
The study found that offsetting the methane and nitrous oxide emissions from the global livestock industry would require 135 gigatonnes (135 billion metric tons) of carbon stocks. According to the authors, that amount is nearly double the carbon stored in managed grasslands globally. Some regions would require an increase in carbon sequestration in the soil of up to 2,000% to match livestock emissions. The findings were published in the journal Nature Communications.
Peter Smith, co-author of the study and chair of the Plant and Soil Science at University of Aberdeen, said the study is “a nail in the coffin for the suggestion that carbon sequestration can offset the methane emissions” produced by the global livestock industry, as reported by DeSmog.
The U.S. Environmental Protection Agency said on its website that a single cow emits around 154 to 264 pounds of methane per year. While methane doesn’t last as long in the atmosphere as carbon dioxide, it is about 28 times more potent. Methane is linked to about 30% of global warming, according to the International Energy Agency. Nitrous oxide, another commonly emitted gas from livestock, is a long-lasting greenhouse gas that is about 300 times more potent than carbon dioxide.
In total, livestock emissions are estimated to make up around 11.1% to 19.6% of total global emissions, The Breakthrough Institute reported.
Another study published in March 2023 revealed that veterinary antibiotics used for livestock can further limit the ability of soil to sequester carbon. Further, the March 2023 study noted that the microbial carbon use efficiency on soils under livestock areas was 19% lower than areas with native herbivores.
In New Zealand, the agriculture industry is already looking toward other methods to minimize emissions, knowing that depending on carbon stocks in soil wouldn’t be sufficient. Professor Louis Schipper at Waikato University told Farmers Weekly, “We already have high soil carbon stocks and no evidence of gains on flat land. A possibly more important consideration is avoiding losses of existing soil carbon stocks, such as from drained peat soil, excessive periodic cropping with bare ground and large offtakes.”
The authors of the new study said the primary goal is to reduce emissions, rather than offset them. In addition to phasing out fossil fuels, the authors suggested solutions such as reducing the number of livestock, improving animal health and better managing livestock waste.
Additionally, the authors wrote that there will need to be more efforts to restore grasslands, preserve their stored carbon and continue to increase carbon stocks.