|Rotz, Clarence - Al
|HRISTOV, ALEX - Pennsylvania State University
Submitted to: Hoard's Dairyman
Publication Type: Popular Publication
Publication Acceptance Date: 5/28/2019
Publication Date: 7/8/2019
Citation: Rotz, C.A., Hristov, A. 2019. Are our cows causing an increase in global warming. Hoard's Dairyman. P. 398-399.
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. For dairy cows in the U.S., this claim cannot be supported by science and the information available on our production systems. The accusations are being made because of limited understanding of the role cattle in the cycling of carbon on earth. The methane that cows produce is part of a natural carbon cycle that has been happening since the beginning of life on our planet. Within about 12 years of its release, the methane is recycled back to carbon dioxide and no longer exists in the atmosphere. Thus, this carbon cycling has a relatively short-term effect on the atmosphere. 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. The fact remains that cows produce a lot of methane. Enteric 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 milk with less feed consumed. Dietary changes can reduce enteric methane production, and feed supplements are being explored to improve feed efficiency and reduce emissions. Alternatives in manure management such as covered storages and anaerobic digestion can also reduce emissions. So, although dairy cows in the United States are not contributing to an increase in global warming and related climate change, there is still benefit in mitigating their emissions. Reducing any source of greenhouse gas emission will benefit our planet.