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ARS Home » Northeast Area » University Park, Pennsylvania » Pasture Systems & Watershed Management Research » Research » Publications at this Location » Publication #361585

Research Project: Sustainable Intensification of Crop and Integrated Crop-Livestock Systems at Multiple Scales

Location: Pasture Systems & Watershed Management Research

Title: Are cattle in the U.S. causing an increase in global warming

item Rotz, Clarence - Al
item HRISTOV, ALEX - Pennsylvania State University

Submitted to: Popular Publication
Publication Type: Popular Publication
Publication Acceptance Date: 3/6/2019
Publication Date: 7/24/2019
Citation: Rotz, C.A., Hristov, A. 2019. Are cattle in the U.S. causing an increase in global warming. Popular Publication. P. 1. Available:

Interpretive Summary: No Interpretive Summary is required for this Popular Publication. JLB.

Technical Abstract: Over the past decade, we have seen the media place blame for our changing climate on cattle. Cattle do produce a lot of methane gas, primarily through enteric fermentation in their rumen and fermentation in their manure. Methane is a powerful greenhouse gas that, along with nitrous oxide, carbon dioxide and some other compounds in the atmosphere, create a blanket around our planet to keep us warm. Our current problem is that our blanket is thickening. The methane that cattle produce is part of a natural carbon cycle that has been happening since the beginning of life on our planet. This methane is oxidized in the atmosphere through a chain of reactions. Within about 10 years of its release, over 90% of the methane is removed from the atmosphere with the carbon in the methane ultimately transformed back to carbon dioxide. This replaces the carbon dioxide that was originally drawn from the atmosphere and fixed in crops to produce feed. In contrast, when we burn fossil fuels, we are taking carbon that has been stored in the earth since pre-historic times and converting it to “new” carbon dioxide released to the atmosphere where it will be with us for 1000s of years. Whereas cattle are part of a natural cycle with short-term impact, burning of fossil fuels has a much more permanent impact. Cattle do produce a lot of methane, and this methane is essentially wasted energy escaping the rumen. Reducing this waste by increasing the efficiency of the rumen may provide a substantial benefit by producing more meat or milk with less feed consumed. Dietary changes and feed supplements can reduce enteric methane emissions and improve feed efficiency. So, although cattle in the U.S. are not contributing to the increase in global warming and related climate change, they may become part of the solution by reducing the greenhouse gas they produce.