By Jessie Haas
According to Walter Jehne of Healthy Soils Australia, hydrology governs 95% of the heat dynamics of the planet. That is water, cooling us and the earth, managed by plants and the soil carbon sponge.
Image: Flickr/Ryan Thompson
We humans have been oxidizing the soil for the last 10,000 years as we cut, plowed and burned fields, left ground bare, applied chemicals, destroyed soil micro-organisms. Just in the past hundred years, agricultural soils have declined from 5% carbon to less than 1% in many places. That carbon is in the atmosphere, trapping heat, and not in the soil, managing the cooling effects of water.
Using grazing animals to restore soil carbon is widely recognized to be essential to turning that around. That’s why the Food, Climate Research Network’s (FCRN) “Grazed and Confused” report (that was published in Issue 49 of Green Energy Times) is so discouraging, with its firm headline-grabbing conclusion that grass-fed beef is “in no way a climate solution.”
FCRN examined a large basket of grazing practices, many very old-school. More recently, a study by Michigan State University (MSU) and the Union of Concerned Scientists showed that cattle finished on grass in the Midwest sequester enough carbon to completely offset their methane emission. Their lead researcher says, “This research suggests that … adaptive multi-paddock grazing can contribute to climate change mitigation through soil organic carbon sequestration and challenges existing conclusions that only feed-lot intensification reduced the overall beef greenhouse gas footprint . . .”
Who’s right? The MSU study is narrower and deeper. It takes into account all associated emissions from feedlot and pasture finishing. It also avoids a major mistake made by FCRN. Their study assumes large inputs of fertilizer, and mechanized management, causing CO2 emissions. But that’s not how grass-fed works. At worst, cows are turned loose on pasture to fend for themselves. At best, they move from one small paddock to the next, grazing, fertilizing the ground with their manure, and requiring only that someone walk out and open the next gate. The MSU/UCS study takes that reality into account. That and its focus on a modern, advanced grazing system probably accounts for the difference. Carolyn Grindrod of Wilderculture notes that “Well-managed pasture is a HUGE photosynthetic cell that cools the planet, filters pollution, prevents heat hazes, keeps the water in the ground and rivers, and as a by-product produces a nutrient-dense food source that humans are well-adapted to eat.”
Grazing can’t be properly understood as a simple carbon-to-methane ratio. They are part of a complex biological system that we humans have unbalanced. According to Walter Jehne, “Nature created our soils, bio-systems, their hydrology and climate via carbon drawdown rates that exceeded oxidation rates, yet for 10,000 years we have reversed this. While plant photosynthesis is critical to fix solar energy into plant bio-mass, it is what happens next to that biomass that matters. Does it rapidly oxidize back to CO2 by burning or does it get partly bio-converted by fungi into stable soil carbon? There are no other options. We live in the balance between fire and fungi.”
Cattle on pasture tip the balance toward fungi, and scientists are finding ways to make them even more effective. A California study finds that spreading compost on rangeland resulted in far greater carbon sequestration. Meanwhile feeding seaweed, tannin-rich leafy fodder, and common mineralized salt blocks can reduce enteric methane significantly.
Managed grazing is recognized as a climate solution by the IPCC and Project Drawdown, among many others. Buying grass-fed beef is one way consumers can help soils tip the balance from fire to fungi.
Jessie Haas has written 40 books, mainly for children, and has lived in an off-grid cabin in Westminster West, VT since 1984, www.jessiehaas.com. Links available with the posting of this article on the GET website.
Additional links:
https://www.ipcc.ch/publications_and_data/ar4/wg3/en/ch8s8-4-1-2.html
http://www.globalcoolingearth.org/wp-content/uploads/2017/09/Regenerate-Earth-Paper-Walter-Jehne.pdf
http://www.drawdown.org/solutions/food/managed-grazing
https://wilderculture.com/blog/grass-fed-meat-and-carbon-why-everyone-is-missing-the-point/
https://www.nytimes.com/2018/04/18/magazine/dirt-save-earth-carbon-farming-climate-change.html
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