Can cattle, fed solely on grass, reverse climate change? Scientific studies are pointing in that direction.
Of all the animals that humans eat, cattle get the worst rap from environmentalists. It’s because conventional, grain-fed steer consume more “energy intensive” food than other livestock. Cows also produce more methane—a powerful greenhouse gas.
Growing grain to feed cattle requires fossil fuel-based fertilizers, pesticides and transportation. It’s said that conventional cattle ranching takes from the planet, without putting anything back.
That mindset changes with 100 percent grass-fed cattle. In fact, Michael Pollan, author of “the Omnivore’s Dilemma,” states, “Grass-fed beef has a much lighter carbon footprint” than its grain-fed counterpart.
Grass and soil store carbon
Grass-fed animals rotate among pastures of perennial grass, trimming the blades like lawn mowers to spur new growth. Their tramping works manure and other decaying organic mater into the soil, turning it into a rich layer of humus. The humus feeds the grass plant’s roots, which helps maintain the soil’s health by retaining water and microbes.
It’s a well-known fact that trees draw carbon dioxide from the air and store it as carbon—an important natural process that curbs global warming. Soil rich in organic matter does the same. A Duke University study found that grass stores vast amounts of carbon too—it gets shelved in its underground root mass. In fact, natural grasslands can be just as effective at sequestering CO2 as forests.
Pasture reduces topsoil erosion
Not only does pastureland absorb carbon, it also prevents erosion. According to eatwild.com, an informational website on pasture-based farming, the U.S. is losing three billion tons of nutrient-rich topsoil each year.
It’s believed that growing corn and soy for animal feed using conventional “row” farming methods causes a significant amount of topsoil loss. “Compared with row crops, pasture reduces soil loss by as much as 93 percent,” reports eatwild.com. A University of Wisconsin study compared the loss of topsoil in pastured land and rowed crops. It found sloped land devoted to corn and soybeans lost six times more topsoil each year when compared to sloped pastureland.
Beef with a Better Carbon Footprint
Yes, methane gas is a by-product of ruminant digestion—a process where plant-based food is digested by initially softening it in the first of four stomachs, called a rumen. The semi-digested food is regurgitated and re-chewed as “cud” before again swallowed for further digestion (goats, sheep, bison, deer, antelope and nine other animals are also ruminants). The resulting gas is even more potent than carbon dioxide in trapping the sun’s heat. While cattle fed-and- finished on grass produce more methane (by eating high-fiber grass) than grain-fed cows, their net emission, or carbon footprint, is lower because grass-fed animals help the soil sequester carbon.
Proving this fact was a study by the Institute for Environmental Research and Education. It found raising ruminants on pasture offsets the animals’ methane production and may actually reduce greenhouse gases. More research needs to be done on this issue. To see a graph detailing the study’s findings, visit http://eatwild.com/environment.html.
According to TIME magazine, some researchers hypothesize that a one percent increase in carbon sequestration on vast acreages of healthy, productive land could be enough to capture the total equivalent of the world’s greenhouse gas emissions.
Grass-Fed Beef and Climate Change
As the grass-fed beef industry requires healthy and productive pastureland, it seems logical that grass-fed cattle can play a key role in reversing global warming. With the planet feeding nine billion people by 2050, it makes sense to eat food that’s cultivated using environmentally sound and sustainable methods. The Natural Resources Conservation Service reports, “properly managed grazing is one of the most energy-efficient ways of producing food and fiber.”
Hawaii pastureland: Mark Thorne
Closeup shots of numbered cattle:: Fern Gavelek