Calculating the carbon footprint of our grass fed beef!

I've always wanted to know where I stand in the grand scheme of things. Towards this end, the 6 years old me drew a lot. When I was 15 I started writing poetry and songs. This week I crunched the numbers to calculate the carbon footprint of my grass-fed beef career. I wanted to know if on the major global processes and carbon cycling scheme of things I am part of the problem or part of the solution. What I found out is surprising. It looks like as far as cow farming endeavors go, our grass fed beef farming may go a long ways to solving one of the most pressing environmental problems of our time-global warming.

Most of us have some sense of what global warming is, and most of us accept that humans are actually driving a global warming event by increasing the amount of carbon in our atmosphere and slowing Earth's cooling rates by creating a carbon-dense blanket in the air that traps the planet's heat. Fewer of us understand how human actions lead to carbon getting into the atmosphere. Let me start by explaining how carbon gets into the air at Wild Mountain Farm. This is the part about how we contribute to the problem, but I hope you can hold your judgment until closer to the end of this story!

When we drive vehicles powered by fossil fuels, carbon locked into photosynthesizing organisms millions of years ago, from the ancient oceans and lakes mainly is finally released through the exhausts of our vehicles. This and other combustion engines based on gasoline and diesel fuel contribute to carbon in the atmosphere. When I drive my truck to move the cow herd to and from wintering grounds, or drive an animal to the provincially inspected abattoir, or deliver meat to customers in Wolfville or Halifax, long bound-up carbon finds its way back to the atmosphere, now in the form of the (greenhouse) gasses like carbon dioxde and methane. How much carbon? About 5-6 tonnes to run our half ton truck for the year to do all that, including a little bit from my helpers fuel efficient car and some from friend's trucks who help transport the herd sometimes.

In Nova Scotia's case, a whole lot of carbon gets released to generate our electricity. This is because most of it still comes from fossil fuel-powered generation plants. Some provinces like Quebec generate most of their power from damned up rivers, but not us. Our electricity has a lot of carbon-release associated with it, at least until we get more from wind, tidal flows, or the sun. To run the coolers where our meat is aged, to run the lights, meat saw, and meat grinder at Reid's Meats where the meat is cut up, and to freeze the meat until it gets packed for customer orders, it all takes power and that power's generation puts carbon into the atmosphere. How much carbon? About 16-20 tonnes per year according to my calculations, most of this to run our walk-in freezer all year.

But what about the herd itself? For their role in the rumination process where they make meat and milk from grass and hay, cows have become famous for their burping and farting, expelling methane and carbon dixide. Methane has a "carbon equivalent" figure we include in the calculations, just like carbon dioxide. Using the numbers from a farm carbon footprinting calculator available online (called CPLAN), our herd of about 50 mother cows and 80 some young animals represents a carbon output of about 72 tonnes per year. Add to this another 3 tonnes per year to run the Diesel engine in our tractor to spread manure on hay land and to put up and transport hay to get the animals through the winter and the total cow carbon out-put for the herd is a hefty 75 tonnes per year! Still holding your judgment? Be patient!

When you add together these stages of production, processing, and distribution, you find the total output to be a whopping 101 tonnes of greenhouse gases released into the atmosphere per year from our grass fed beef enterprise on Wild Mountain Farm. Of course these are estimates based on standards for average scenarios calculated by competent scientists, we'll assume.

Now you're wondering where the good part is, right? To understand the kicker in all this, you'll have to understand a little about grass-land ecology and nutrient cycling. Once upon a time herds of herbivores grazed grass-based ecosystems on massive scales. Sun powered photosynthesis in plants, turning atmospheric carbon into plants, and herds of grazing animals ate some of the grass, but stomped a lot of it into the soil (where the carbon-dense roots are too) and they left behind manure and urine to fertilize the process. As they moved from new grass to new grass, the grass kept growing, and the soil kept building up. Organic matter in the form of stomped-in grass, roots, and manure constantly entered the soil. This soil developed through time to have more and more organic matter build-up. This organic matter is mostly carbon, bound-up and secured into deep and fertile soil. We measure it as percent organic matter. Historical grassland ecosystems maintained by herbivore disturbance typically contain 10 percent or more organic matter-call it carbon--in the upper 12 inches of soil. This was the making of the great plains for example, created and maintained in the timeless grazings of sixty million or so bison.

Then comes settlers, then comes the bread basket, then comes industrial agriculture. Now the same soils usually have less than a third of the carbon richness, and the rest of it has gone to the atmosphere because the fertility inputs were replaced by chemical-based fertilizers, subtracting most of the carbon from the cycle. Basically, cheap energy from fossil fuels lead us to take an approach to agriculture that favored larger is better philosophies as political forecasters set the stage for a globalized economy. The successful world players became the ones who could produce the cheapest commodities for export throughout the world.

Like no time before in human history we could produce food so easily and on such a scale that we ended up with grain crops far beyond humans' abilities to eat them. So, we did the next reasonable step--we decided we could feed the grains to cattle. To keep it simple, economically efficient, and scalable, we put the cattle in feedlots. Cattle and other ruminants until this point had always been the means for using the vast majority of farmland-pasture. Grain was used sparingly because it was previously a labor-intensive crop to plow, plant, weed, and harvest, and cattle were well designed to not need grain. In the process, we had forsaken the invaluable process of carbon sequestration in grasslands and unlocked billions of tonnes of carbon into the air.

This all being said and done, where is the hope to finish the carbon footprint equation in this story with a positive sum. We need to measure the carbon sequestration component of the Wild Mountain Farm grassland landbase used to support our cattle herd. Work to this end inadvertently happened this past summer. As part of the government initiated Nova Scotia Grass Fed Beef project, I was able to have 28 fields we farm as pasture or hay production (or both) tested for soil nutrient analysis. Part of soil analysis tests is to quantify the percentage of soil organic matter-the amount of carbon stored in the soil. Here are the results. Of the fields, 11 were predominately small hay fields, with a soil organic matter averaging 7.1%. The other 10 fields were used mostly for pasture (though sometimes hayed first in the springtime), and had been in pasture for at least 10 years. The organic matter was predictably higher than the hay fields, averaging 9.6%.

The conclusion here is that these fields are high in stored soil carbon, especially the pastured fields. For a reference, the lowest testing field was 3.7% organic matter, a field I had just seeded to grass land this spring for the first time. Previously it was being successively cropped for corn, soybean, and wheat by a neighboring dairy farmer. The highest testing field registered a whopping 16.0% organic matter. This is a field at our home farm that has been in permanent pasture and hay production since I was 4 years old (so 35 years ago). I remember my dad seeding it down to red clover, white clover, and timothy grass.

The take home point is that our fields have a lot of stored carbon, and the longer they have been in pasture it seems the more carbon they have stored. But here is the super interesting finding and the grassy glory of this story. Seven summers ago I soil tested five fields I was farming at that time. These same fields were all part of the 2013 tests, three pasture fields and two hay fields. I dug out the results of that old test and was able to get some very real insight into what grass fed beef farming has been doing for soil carbon over the last seven years. Over this period, the hay fields on average increased in organic matter 0.3 of a percentage point, while the pasture fields increased an impressive 3.0 percentage points, or an average of 0.04 and 0.4 percent per year respectively.

So what does this mean in terms of the amount of atmospheric carbon being removed from the air and stored in the soils of Wild Mountain Farm? Soil scientists estimate that one percentage point of organic matter in the upper 12 inches of soil represents a total carbon weight of 8.4 tonnes per acre of land. At Wild Mountain Farm, to support our cow herd we farm approximately 300 acres of grassland, half as mostly pasture and half as mostly hayland. Using our last seven years on the five fields tested as the benchmark, the calculation for carbon sequestered per year would be 0.04 percentage points of organic matter x 8.4 tonnes per acre x 150 acres of hayland + 0.40 percentage points of organic matter x 8.4 tonnes per acre x 150 acres of pasture = 554 tonnes.

These figures suggest that the grasslands farmed for grass fed beef at Wild Mountain Farm sequester 554 tonnes of atmospheric carbon per year! Revisiting the first half of our equation, the 101 tonnes of carbon we released from cow farting, haying, meat processing, and food distribution, the total net carbon footprint of Wild Mountain Farm's grass fed beef enterprise is actually very positive at 554-101=453 metric tonnes of carbon sequestered into the soil per year! This is about 10 metric tonnes sequestered for each of the 45 or so beef animals we produce for our customers each year!

This finding came as an unexpected and exciting surprise! I wish I could point you to some figure that would show how if we all choose grass fed beef it could save the whole world. Some scientists suggest we could remove the greenhouse effect if we could remove about 167 billion metric tonnes of carbon from the atmosphere and store it back into the world's agricultural lands. In terms of soil organic matter, this translates to an increase of about 1.6 % of global agricultural soils. At 0.4 % increase per year at Wild Mountain Farm this only took four years to achieve for the section of the planet we graze, though it would take 40 years or better management to do the same on our hayland.

So, in the grand scheme, I'm not a nomad following the herds but I figure my time as a grass fed beef farmer is time well spent. The benefits of grass fed beef literally outweigh the costs, tonne for tonne!

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3 comments

Thank you for spelling it all out, multiplier by multiplier. Even when the numbers look bad at first. The way I shall remember this story in short: Pasture-raised local meat is another form of the practice of “no-till” farming, which is being rediscovered worldwide as a way to sequester more and more carbon each year, while simultaneously fertilizing the grasslands. Pasture animals digest the additional organic material before it goes back into the ground, increasing it’s nutrient density, but no-till wheat farmers in eastern Washington (Shepherd’s Grain) are finding similar increases in percent organic matter and carbon storage, I heard. Thanks for your story’s level of detail again.

Maria Everhart

Well done! Great article.

Kevin

Thanks for this well thought out and presented posting. It frustrates me when people claim that feedlot cattle is better for humans or the earth- especially when those people are journalists. It looks like the methane production from a feedlot cow is less. However, they aren’t sequestering any carbon to make up for it. If you take a farm with cattle that get fed no outside inputs and have soil that is increasing in carbon content every year, it makes sense that there MUST be a net carbon sequestration taking place. And it sounds like the amount being sequestered is far more than the carbon required for transportation and electricity on your farm.

Presumably if you really wanted to push the envelope, a methane digester running on the barnyard manure could someday produce enough gas to run a natural gas powered vehicle and provide the electricity needs of your operation.

Keep up the great work.

Luke Parkhurst

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