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United States Department of Agriculture

Agricultural Research Service

Title: Our Role in Global Warming Through Ruminants

Authors
item Fisher, Dwight
item Burns, Joseph

Submitted to: Southern Pasture and Forage Crop Improvement Conference Proceedings
Publication Type: Proceedings
Publication Acceptance Date: June 15, 1996
Publication Date: N/A

Interpretive Summary: Greenhouse gases result in a net warming of the earth. Two of those gases (carbon dioxide and methane) have increased substantially since the industrial revolution. Sources of methane have been identified but the relative sizes of the sources are open to question. The largest man-made source of methane is paddy rice production. Domesticated ruminants also produce large amounts of methane. Developing nations have most of the ruminant animals and produce 5 to 7 times more methane per unit of product than North American production systems. However, use of gasoline in the US contributes much more to global warming. Currently, about 80% of our energy comes from fossil fuels (coal, petroleum, and natural gas). World development in the US model of prosperity may not be sustainable. Both major agricultural sources of methane (rice and ruminant production) are too small in relation to the carbon dioxide from fossil fuels to provide effective control points for global warming. If the negative impact of global warming is minor, it will be because we were fortunate and not because we thought through the possible consequences of our actions and acted prudently.

Technical Abstract: Carbon dioxide (CO2) has increased from 270 ppm at the beginning of the industrial revolution to approximately 360 ppm and methane (CH4) has increased from 750 ppb to approximately 1800 ppb. Sources of CH4 have been identified but their relative contributions are open to question. The largest man-made source of CH4 is paddy rice production. Domesticated ruminants produce about 9% of the total CH4 released into the atmosphere. Africa, Latin America, Asia, and the Near East account for over 60% of the animal units. Developing nations produce 5 to 7 times more CH4 per kg of product than North American production systems. Gasoline consumption in the US contributes about 1,000 Tg of CO2. Currently, about 80% of the energy we generate comes from fossil fuels (coal, petroleum, and natural gas). World development in the US model of prosperity may not be sustain- able. Both major agricultural sources of CH4, rice and ruminant production, ,are too small in relation to the thousands of teragrams of CO2 from fossil fuels to provide effective control points for global warming. If the negative impact global warming is minor, it will be because we were fortunate and not because we thought through the possible consequences of our actions and acted prudently.

Last Modified: 11/22/2014
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