Sustainability in Agriculture: Using Plants to Capture Carbon

Mark Johnson
6 min readApr 8, 2021

Agriculture is responsible for about a quarter of global greenhouse gas emissions.

Given the scope of the general problem of sustainability in agriculture, I’ve been researching how to address carbon emissions at the farm level. Since the market is focused on carbon sequestration, that’s where I’ve focused my attention.

Why is carbon sequestration such a hot topic? My working thesis is as follows:

  • There’s no silver bullet for sustainability in agriculture.
  • We must focus on solutions that are effective and easy-to-adopt within the current system.
  • Farmers are driven by ROI.
  • Land-use change is a major contributor to agricultural emissions.
  • Plants remove carbon from the atmosphere.
  • More science needs to be done to understand carbon capture.
  • We need a ledger to track emissions and a marketplace to buy and sell credits.
  • There is a lot of innovation in this space.

This post is a combination of my own research and a reflection of a the conversation we had last week in our Entrepreneurs in #AgTech Clubhouse, which will be continued this Friday. I’d welcome comments from industry experts, companies working to address sustainability, and, perhaps most importantly, the perspective of farmers themselves.

There’s no silver bullet for sustainability in agriculture

In the world of energy, it’s generally agreed that ultimately, we need to stop pumping hydrocarbons out of the ground. Folks will disagree on the timeline — whether it’s going to be decades or tomorrow — but the idea of creating cheap (essentially free), portable, zero-emissions energy, is a clear end goal. Technologies like nuclear, solar, and wind, combined with advanced batteries, are a framework for achieving zero-carbon energy.

Unlike energy, the sustainability response from agriculture is murkier.

Plants are wondrous little machines, utilizing the natural resources of the planet — sunlight, water, nutrients in the soil — to create the sugars and proteins we humans need as energy.

Plants aren’t going away any time soon, so we need to figure out how to grow enough food for the planet while doing so as sustainably as possible.

We must focus on solutions that are effective and easy-to-adopt within the current system

In the above graph, the x-axis is the ease of adoption and the y-access is the impact on greenhouse gas emissions.

Dreaming about big solutions may be fun, but often impractical. For example, livestock is a large source of emissions, but converting everyone on the planet to vegetarianism is a fantasy. Though the potential of lab-grown meat from companies like Impossible Foods and Beyond Meat is exciting, we need solutions for today, not decades from now.

How do we find solutions in the sweet spot: relatively easy-to-adopt and high impact on sustainability?

Farmers are driven by ROI

Farmers are the ultimate entrepreneurs, betting every growing season that through a combination of grit and technology, they can bend Mother Nature to their will and grow food to maintain their business.

If we can find solutions that drive positive ROI on the farm and benefit the environment, then we’ll have a far better chance of adoption at scale.

An example of this is how seed technology has improved crop yields in the latter half of the 20th century. Farmers adopt new seed varieties because it increases their yield, improving their revenue; and it means that we need less total farmland to grow more food for the planet.

Graph from research at Purdue.

Land-use change is a quarter of agricultural emissions.

The most striking fact (to me) in my research is that about a quarter of agricultural emissions is from converting natural biomes into farmland. Plants suck carbon out of the atmosphere and store it in themselves (like trees in a forest) and in the ground. Disrupting these processes means less carbon is sequestered naturally.

That means that if we want to have a meaningful dent in carbon emissions, we can’t just focus on the agricultural process, we need to have a long-term path to converting some percentage farmland back to nature, whether that’s forest or tallgrass prairie. That’s a tall order, likely decades in the making.

Luckily, there might be ways to have our cake and eat it too, with a combination of farming practices, including cover crops and soil management.

This entire post from Our World in Data is fantastic.

Plants remove carbon from the atmosphere.

Humans require oxygen to create and return carbon dioxide. Plants are the opposite, and pull carbon dioxide from the atmosphere and return oxygen. We can use this fact to encourage farming practices that maximize the amount of carbon captured in the soil. For example, if we can encourage cover crops and tilling practices that leave soil undisturbed, there’s the potential to store a huge amount of carbon within existing farmland.

Graphic from Mother Jones.

More science needs to be done to understand carbon capture.

Like any cutting-edge science we need a lot more data.

How do we determine how much carbon is being captured? Today, the state of the art involves pulling out multiple soil cores from a field and baking them in an oven. That process is not scalable. Plus, it doesn’t account for the variation in soil types (300,000+) across the US. We’ll need a lot more data so we can accurate estimate how much carbon is actually being sequestered by a farmer.

There are even skeptics who suggest that we’re not capturing nearly as much carbon as we think or creating new problems. For example, some research suggests that increased carbon levels breed microbes that belch out nitrous oxide, an extremely pernicious greenhouse gas. Even if the carbon capture thesis is correct, it will take some serious science to allay all of the concerns.

The worst case scenario is if we put a ton of effort behind carbon capture and find out that we didn’t capture as much as we had hoped.

We need a ledger to track emissions and a marketplace to buy and sell credits.

A carbon credit market works by one party selling carbon credits and the buyer using those offsets against their own carbon output. In order to do that well, it’s critical to track how much carbon is sequestered by a farm, which needs to happen over time. That’s exactly why the science becomes so important.

A challenge here is that the bad taste of the carbon market collapse in 2010 is still felt; and farmers have not shown willingness to enter into speculative markets, even if the promise of additional revenue is there. Less than 1% of farmers have entered a carbon contract, according to this survey.

There is a lot of innovation in this space.

Trace Genomics is trying to better understand soil. Indigo Ag is focused on a grain marketplace with their carbon offering being a centerpiece. Nori has a carbon removal marketplace. Truterra is Land O’Lakes’ ambitious carbon project. And many, many more.

On one hand, all this innovation is great. Venture investors and large companies are putting a lot of dollars behind carbon marketplaces. On the other hand, there is still a lot of noise, which makes it difficult for a farmer to decide to participate in something so new and unproven.

Conclusion

My conclusion is that carbon capture is a fascinating area with lots of promise, but more research needs to be done before we all jump on the bandwagon; plus we’ll need agreement from key actors in the supply chain before it will be widely adopted.

What am I missing? What companies are innovating in carbon? Is there something beyond carbon capture I should be looking at? Where do you see sustainability going in ag?

Interested to hear more from industry experts. We’re actually hosting a second Clubhouse this week because last week’s discussion was rich, but inconclusive. Do join if you can.

A reading list

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Mark Johnson

CTO of Stand Together. Former CEO of GrainBridge, Co-founder of Descartes Labs, CEO of Zite. Love product, philosophy, data refineries, and models.