The Real Contribution To Climate Warming Of Livestock Production

Livestock production is more than grass grazing; it includes all impacts associated with producing meat or dairy, including soil erosion, water pollution, dewatering of rivers for irrigated pasture or hay production, and so on. Photo George Wuerthner

For years, I have suggested that studies conclude that livestock production (not just grazing) is one of the most significant contributors to global climate warming. However, the actual influence of livestock production on climate is obscured due to different accounting methodologies.

GHG emissions resulting from the clearing of tropical rainforests for livestock pasture is one of the most significant contributions to climate warming. Photo George Wuerthner

In the most recent estimates, atmospheric CO2 level was 51 percent above that of the pre-industrial era. In 2023, CO2 concentrations were at 420 parts per million (ppm), methane at 1,934 parts per billion, and nitrous oxide at 336 parts per billion.

Cattle grazing on pasture carved from tropical rainforest. Photo George Wuerthner

A recent 2023 U.N. study estimates that livestock was responsible for only 6 percent of global greenhouse gas emissions. Yet at least one World Watch article suggests that livestock production may contribute to as much as 51% of climate warming.

Other sources conclude that livestock, particularly cattle, are somewhere in between attributing  11 to 20% of all global GHG emissions to livestock.

Dairy cows are a major source of GHG emissions, seen here degrading Point Reyes National Seashore, California. Photo George Wuerthner

How can basic facts diverge so much? It all has to do with what is included in the accounting.

A good analogy would be looking at the profit and loss of a business.  One can’t just count the money consumers spend on the product as the profit. A company must pay rent, power, employees, insurance, taxes, transportation, and other costs that must be deducted from the overall business income to determine the “profit.”  

Dairy cow CAFO operation in Arizona. Photo George Wuerthner

The  U.N. report is a clear example of a narrow definition of livestock climate contributions.

Dairy cow operation on Idaho’s Snake River Plain. The manure, methane emissions ,digestion, and crop production for livestock feed, all are contributors to GHG emissions. Photo George Wuerthner

The report measures only direct emissions: the methane released by digestion, manure, and fertilizers associated with livestock farming.  Other GHG emissions costs are ignored.

However, other studies include a more complete accounting of what some call the “full lifecycle emissions” of the livestock industry’s climate impact. A lifecycle study includes more than the methane produced by livestock.

A bucolic scene like this dairy operation in Vermont obscures the fact that the cow pasture was created by deforestation. Trees store far more carbon than the livestock pasture. Photo George Wuerthner

For example, expanding cattle pasture land is responsible for 41 percent of tropical deforestation, but deforestation emissions are separate under land use, land-use change, and forestry (LULUCF)). Letting pasture return to forest would store far more carbon than any benefits from so-called “regenerative” agriculture.

Throughout the world, but particularly in tropical areas, forests are cleared to create pasture for cattle. The trees are often burned, releasing carbon into the atmosphere. However, more importantly, trees store carbon. Deforestation of the land to create pasture represents a substantial net loss in carbon storage and releases a large amount of carbon when the forest is burned.

Cornfield at farm in Richmond, Vermont. The majority of corn grown in the United States is used for livestock forage, not direct human consumption. Photo George Wuerthner

Other costs of the livestock industry include growing feed like alfalfa, corn, and soybeans for CAFO and even “grass-fed” beef. These, in turn, have other unaccounted ecological costs. For instance, throughout the West, the single biggest consumer of water from rivers is irrigation for livestock feed and pasture, degrading aquatic ecosystems.

The livestock industry has censored U.N. reports on livestock emissions and opposes any recommendations that we should shift to “plant-based diets and that meat is beneficial for the environment. The U.S. Food and Nutrition Service recommends that Americans eat less meat and more vegetables and fruit.

Fruits and vegetables have a significantly lower carbon footprint than meat and dairy production. Photo George Wuerthner

The U.N. report obscures the full impact of the livestock industry on climate warming. Yet shifting one’s diet from dairy and red meat to other foods, whether with fruit and vegetables or other meat sources like chickens, rabbits, and geese, could significantly reduce one’s contribution to climate warming.

One of the easiest ways that individuals can reduce their carbon footprint is through the food choices they make. Photo George Wuerthner

Overall, less meat is the more sustainable diet choice.  As a generalization, plant-based foods tend to have a lower carbon footprint than meat and dairy. In many cases, it has a much smaller footprint.

Comments

  1. Mary Avatar
    Mary

    Red meat isn’t all that good for people, as it is a factor in heart disease.

    ‘Red and processed meat linked to increased risk of heart disease, Oxford study shows’
    https://www.ox.ac.uk/news/2021-07-21-red-and-processed-meat-linked-increased-risk-heart-disease-oxford-study-shows

  2. Todd Shuman Avatar
    Todd Shuman

    From Reisinger and Clarke, 2017 :
    << Abstract
    Agriculture directly contributes about 10
    -12% of current global anthropogenic greenhouse gas (GHG)
    emissions, mostly from livestock. However, such percentage estimates are based on Global Warming
    Potentials (GWPs), which do not measure the actual warming caused by emissions and ignore the
    fact that methane does not accumulate in the atmosphere in the same way as CO2. Here we employ
    a simple carbon cycle
    -climate model, historical estimates and future projections of livestock emissions to infer the fraction of actual warming that is attributable to direct livestock non
    -CO2 emissions now and in future, and to CO
    2 from pasture conversions, without relying on GWPs. We
    find that direct livestock non
    -CO2 emissions caused about 19% of the total modelled warming of
    0.81°C from all anthropogenic sources in 2010. CO2 from pasture conversions contributed at least
    another 0.03°C, bringing the warming directly attributable to livestock to 23% of the total warming
    in 2010. The significance of direct livestock emissions to future warming depends strongly on global actions to reduce emissions from other sectors. Direct non-CO2 livestock emissions would contribute only about 5% of the warming in 2100 if emissions from other sectors increase unabated, but could
    constitute as much as 18% (0.27°C) of the warming in 2100 if global CO2 emissions from other
    sectors are reduced to near or below zero by 2100, consistent with the goal of limiting warming to well below 2°C. These estimates constitute a lower bound since indirect emissions linked to livestock feed production and supply chains were not included. Our estimates demonstrate that expanding
    the mitigation potential and realizing substantial reductions of direct livestock non
    -CO2 emissions
    through demand and supply side measures can make an important contribution to achieve the stringent mitigation goals set out in the Paris Agreement, including by increasing the carbon budget
    consistent with the 1.5°C goal

  3. Ted Heisel Avatar
    Ted Heisel

    Thanks for publishing more inconvenient truths about our impact on the planet. Additionally, beef is terribly inefficient, converting only around 2% of caloric input into useable output (i.e. meat), which is a significant reason there are essentially no eastern tallgrass prairies remaining in the U.S., instead about 90 million acres of corn fields.

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George Wuerthner is an ecologist and writer who has published 38 books on various topics related to environmental and natural history. He has visited over 400 designated wilderness areas and over 200 national park units.

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