Soil as the Ultimate Carbon Sink

December 5, 2019

Wall Street Journal:

AINSWORTH, Iowa—What if there was a way to combat climate change that didn’t require technological breakthroughs, carbon taxes or eliminating all fossil fuels?

Such a solution might lie here in an Iowa cornfield beneath the feet of Mitchell Hora, a seventh-generation farmer. Mr. Hora experiments with “regenerative growing practices” that improve soil health, boost yields, reduce water and fertilizer use, and carry a significant collateral benefit: they sequester in the soil carbon released from burning fossil fuels.

Mr. Hora could soon be rewarded for providing this social benefit. Indigo Ag Inc., a Boston-based company specializing in agricultural technology and management, is setting up a market for carbon credits. Companies and consumers with voluntary or compulsory commitments to reduce their carbon footprint can, rather than reduce emissions themselves, pay farmers to do it for them. Via the Indigo Carbon marketplace, they can pay farmers like Mr. Hora $15 to sequester one metric ton of carbon dioxide in the soil.

“I’ve been doing all of this out of my own pocket,” says Mr. Hora. “Most farmers cannot take on that kind of risk, to experiment and to try to change. But now, with Indigo Carbon, it gives them that incentive to actually try.”

David Perry, Indigo’s chief executive, is almost messianic about the potential: “We could soak up half to 100% of all the carbon dioxide emitted since the industrial revolution,” or roughly one trillion tons.

The Rodale Institute, a think tank that promotes organic agriculture and has partnered with Indigo, cites trials that suggest through regenerative growing practices, an acre of agricultural land can sequester one to 2.6 tons of carbon dioxide a year. Extrapolating to the world, that equals the about 37 billion metric tons of carbon dioxide released globally through fossil fuel use each year.

That’s not realistic, according to Rattan Lal, a soil scientist who heads the Carbon Management and Sequestration Center at Ohio State University. He says the maximum soil sequestration that can be achieved, under ideal conditions, is nine billion tons and even that—given the political and practical obstacles—“is a dream.” In 2015 France persuaded the world to commit to raising the carbon content of soil by 0.4% per year and it has yet to trigger any meaningful action.

A more feasible goal, he says, would be six billion tons globally, including one billion in the U.S. That won’t absorb all or even most fossil-fuel emissions, but could offset those from sectors with no realistic alternative to fossil fuels, such as aviation and steel making.

Longer piece here deserves a click thru if you want more perspective.

Civil Eats:

Farm country is abuzz about the latest in carbon market opportunities. Boston-based agtech company Indigo Ag announced in June that its Terraton initiative will pay farmers $15 per metric ton for the carbon that they store in their soils and in trees on their farms.

The company, which has raised over $600 million in investors since it was founded in 2016, says it intends to remove one trillion tons of carbon dioxide from the atmosphere in part by using a patented microbial seed coating and digital technology that allow the company to monitor and track soil carbon and on-farm emission levels.

A spokesperson from Indigo Ag says that the response has been overwhelming, with farmers signing up millions of acres in the United States and abroad. He added that carbon credit buyers—large retailers, food companies, and more—are also knocking on their door, wanting to purchase the carbon credits generated by farmers committing to the company’s carbon program.

This move toward reviving a new form of voluntary carbon market prompts a number of big questions. What does it mean for those who want to advance sustainable agricultural solutions to climate change? How does it fit into the larger landscape of efforts to transform farming and address our climate crisis? And will it ultimately pay off for farmers?

Early Carbon Markets

The Chicago Climate Exchange was the first national effort to put a carbon market in place. The Exchange set up a market for offset credits generated by farmers and ranchers whose practices reduced greenhouse gas emissions and increased carbon sinks on agricultural lands—practices such as rotational grazingconservation tillage, and prairie plantings. Companies and local governments would buy those credits as a way of offsetting their own greenhouse gas emissions.

I was working in Wisconsin in 2006 when the state’s Farmers Union began reaching out to dairy producers and other farmers offering to pay them for their climate-beneficial practices. The response was considerable: Within two years, the Farmers Union had 2.6 million agricultural acres under contract with the Chicago Climate Exchange in Minnesota, Wisconsin, Montana, and the Dakotas. The Iowa Farm Bureau had another 600,000 acres under contract.

But by 2010, the exchange had collapsed. The carbon market was swamped with offset credits from willing farmers, but it didn’t have enough buyers. As a result, the price of the carbon credits went from a high of roughly $7 to just 5 cents per metric ton of carbon. In December 2010, the Chicago Climate Exchange closed its doors, leaving farmers and ranchers without support for their carbon farming efforts.

The next effort to create a carbon market came from California. In 2012, as part of its climate change law, the state launched a cap-and-trade program, requiring large greenhouse gas emitters to participate. Now, seven years later, there are still very few ways for farmers to earn carbon credits, and they include installing dairy digesters and taking up certain rice management practices, both aimed at reducing methane emissions. But with a low carbon price and high transaction costs for farmers, only the dairy digester projects have sold carbon credits, largely because of other state financial support for the projects. Meanwhile, the state’s rice producers have stayed out of the California carbon market.

15 Responses to “Soil as the Ultimate Carbon Sink”

  1. redskylite Says:

    Much discussion on terrestrial carbon sinks and Mr Hora certainly is working hard to improve agricultural land management, as I hope agricultural colleges are too in this day.

    Under the weather extremes we are experiencing worldwide lately, I wonder how effective carbon management will be under flooded and drought parched lands however.

    Mangroves, wetlands, humble bogs and kelp forests are also much studied possible sinks that can be enhanced. When I read about some of the draconian artificial geoengineering ideas, I’m glad that universities and individuals are researching and actively working to improve carbon sinks of all varieties.

    Not so sure that steel must use fossil fuel to be manufactured – seem to remember reading about reduced carbon heavy processes being employed.


    “Why bogs may be key to fighting climate change”

    Plant material is broken down by enzymes in microorganisms, but in peatlands there are an assortment of compounds called phenols that stop the various enzymes working.


    Apple buys first-ever carbon-free aluminum from Alcoa-Rio Tinto venture

    The carbon-free move is a response to consumer, activist and investor demand for firms to lessen their emissions

    • doldrom Says:

      Steel making depends on coking coal.

      Even before the industrial age, people were not able to use iron until they had perfected using charcoal in ovens with bellows.

      • redskylite Says:

        The article I read was a plan to realized in 2045 to use “hydrogen produced from “clean” electricity” a joint venture from SSAB, LKAB and Vattenfall – I guess we have too wait to see it in action. TATA are exploring carbon capture & Boston Metal has developed technology to electrify steelmaking, and a pending funding round will kick-start a large demonstration project. Nothing in practise yet.

    • indy222 Says:

      While you’re thinking about bogs and peatlands…. don’t forget the new instability discovered a few years ago – the “Compost Bomb Instability”, which triggers when the local atmospheric temperature rises at a rate of 0.88C per decade and stays at or above that rate for 15+ years. That rate is, for the Arctic peatlands, within the trends predicted.

      The other worry is that at all wetlands, there is a strong consistent methane emission rise rate vs temperature. The numbers work out to 44% rise in methane release rate for a 1% rise in absolute temperature. (Yvon-Durocher et al 2014)

  2. Greg Wellman Says:

    Yeah, I have to agree with the soil scientist who says that’s not realistic. Yes, some carbon sequestration by soil creation/enrichment is possible, but we haven’t achieved any yet, and are likely to only achieve enough to offset emissions “from sectors with no realistic alternative to fossil fuels, such as aviation and steel making” as he says.

    • Brent Jensen-Schmidt Says:

      Not the silver bullet, but it is being done successfully. Recently viewed a number of docos and reports, of high probity, featuring individuals and outfits actively improving their soil. The important thrust was the vastly improved yields and economics. The grins were wide on the faces. Win win.

    • Keith Omelvena Says:

      But then, if the consumption of air travel and steel products was to substantially reduce? As it needs to!

  3. indy222 Says:

    IPCC values from the AR5 were more like 18% of our emissions as an optimistic estimate. We of course need to rehab our soils – without soils, we’re pretty much doomed. But the carbon market?…

    This looks like an area ripe for fraud. Get paid for carbon “sequestration” and ignore that it’s only caught in the fast carbon cycle, not sequestered. Get your money, and then when the carbon comes out later due to drying soils, indirect warming from indirect CO2 and methane from the permafrost, rising temperatures in the tropics triggering more rapid methane creation (a 44:1 amplifier)…. and then where are you? Not good.

    Worse is getting paid carbon offsets for palm oil tree planting in the rainforest – after illegal cutting of the trees that are adapted to be there. What a racket!

    • rhymeswithgoalie Says:

      Aye, surface vegetation is transient carbon storage (lumber for furniture and structures may sequester it longer). Deep-rooted plants can sequester carbon below the area of rot.

  4. doldrom Says:

    Soil sequestration (and carbon sequestration generally) is a little like new battery technologies. It all sounds very promising, but it’s rare to read about how it’s taken off and earning billions somewhere …

  5. toddinnorway Says:

    We need a portfolio of solutions to reduce GHGs. Biochar is definitely one of them. In other words, it is deeply unrealistic to expect biochar will solve the entire GHG emissions problem. The offset market is already selling negative emissions offsets from biochar produced and used in Finland. A competing offset market is the setup. Their prime offset solution is biochar. They have completed some pilot auctioning, and plan to ramp up soon.

  6. jimbills Says:

    News today:
    The Arctic may have crossed key threshold, emitting billions of tons of carbon into the air, in a long-dreaded climate feedback

    Update on Madrid talks:
    Madrid Climate Negotiators Seek to Break Deadlock on Role of Carbon Markets

    ‘Negotiations on how carbon markets can be used by countries to meet their global warming goals under the Paris accord go down to the wire this week as United Nations climate talks enter their final days in Madrid.’

    ‘”All of the provisions regarding environmental integrity (of carbon markets) have not been resolved,” said Kelly Kizzier, vice president for international climate at the Environmental Defence Fund.’

Leave a Reply

Please log in using one of these methods to post your comment: Logo

You are commenting using your account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

%d bloggers like this: