Could carbon sequestration be a new untapped market that can save the pocketbooks of US farmers? The easiest way to sequester carbon is to plant more trees- but that would diminish the world’s food supply. The next logical step is for farmers to sequester carbon in their soils, and now there’s a new market that is offering incentives for farmers to participate. The US has the greatest potential of any country for soil carbon storage, and new research shows that cover crops have a role to play in all of it.
No “Magic Bullet” in Carbon Sequestration
Brian Wallheimer of The Pig Site reported on a newly released Purdue University study which found that large-scale carbon sequestration isn’t the magic solution to slowing climate change. The study was study led by Wally Tyner, the James and Lois Ackerman Chair in Purdue’s Department of Agricultural Economics. Tyner, along with the University of Florida’s Luis Moisés Peña‑Lévano, and Farzad Taheripour, a research associate professor of agricultural economics at Purdue, came to this conclusion using Purdue’s GTAP-BIO-FCS model.
The Paris Climate Agreement calls for a reduction of greenhouse gases in order to keep global temperatures from rising 1.5 degrees Celsius since pre-industrial levels. This goal could be achieved if we’re able to reduce our carbon emissions, or by capturing and storing the atmospheric carbon.
One cheap and efficient way to capture carbon is by planting more trees, or increasing forested lands. Forests can store up to 80 or more metric tonnes of carbon per acre. Trees can capture atmospheric carbon through photosynthesis and store it in their roots and in the soil.
Threat to Food Security
However, even if we’re able to reach half the the Paris Climate Agreement’s goal using this method, it would send global food prices soaring. Especially in small, developing economies. Tyner said,
“Significant forest carbon sequestration leads to reductions in food supply at the same time we’re expecting population increases. This is a simple supply and demand problem.”
We would be incentivizing the conversion of cropland to forest at a time when crop yields are anticipated to go down and the world population is growing.
“When we incorporate the overall adverse effects of climate change on agricultural productivity – the cost for society of providing FCS incentives can become a threat for food security because it increases the competition for land between forestry and agriculture, and that significantly boosts crop prices and land rent,” the authors report. “An aggressive FCS policy drives a major decline in food and livestock production across the world leading to substantial increases in food prices, higher than 200 percent in many regions for most agricultural sectors, especially emerging economies.”
Tyner believes that carbon sequestration can play a role in reducing carbon emissions, but crop yields must also be significantly increased.
“Forest carbon sequestration is not the silver bullet. On a small scale, it’s an efficient way to capture carbon. But if you try to take it too far, forest land competes with cropland, and then the poor would see huge increases in food prices,” Tyner said. “If we want to be serious about climate change, we need to implement carbon taxes to see reductions in emissions.”
Carbon Sequestration Market
If planting more trees is the easiest solution to capturing carbon, but doing so would have too detrimental of an impact on the world’s food supply, then it appears a viable option to addressing this problem could lie in agriculture. Not only is there value in increased efficiency and productivity of crops, but farmers could also begin sequestering more carbon in their own soil.
Last month, Virginia Gewin of Successful Farming reported on plans for market to pay farmers for soil carbon and water conservation. Ten companies and non-profit organizations have come together to establish a national market by 2022. Plans have been in the making for two years and the project is largely supported by the Noble Research Institute, which has committed over $2 million. Additional support from the General Mills Foundation, Walton Family Foundation, and McKnight Foundations has been secured.
The market will work in a couple of ways. Farmers will receive credits for the amount of carbon they’re able to sequester in the soil, or credits for improved water quality. Then, companies buy these credits from the farmers, which creates a new stream of potential income for them. For the companies, the market will offset their greenhouse gas reductions with purchased carbon credits.
Jerry Lynch, the vice president and chief sustainability officer for General Mills says the project will help improve soil health and the ecosystem.
“We’ve been scaling [efforts to improve soil health] in our own supply chain. It’s intensive and it’s slow going,” says Lynch. Earlier this week, “we made a public commitment to advance regenerative practices on 1 million acres by 2030. This [market] is a mechanism that can help us do that much more effectively.”
Verification a Challenge
There have been carbon markets before, but they’ve struggled to really take off in agriculture. The cost to farmers to verify and report their carbon storage has just been too high. Nearly 70% of the cost of a credit would go to verification, and that just wasn’t worth it to many farmers.
This time it’s different, says Pipa Elias, soil health strategy manager at The Nature Conservancy.
“We started from an agricultural perspective, and then created the market, rather than trying to fit agriculture into an existing carbon trading system.”
“We’re creating a system that gives growers the flexibility to do what works for their farm, but still generates a societal benefit,” she says.
Farmers will need to have their soil tested before enrolling and before they seek a carbon credit. They plan to begin using more advanced ways to analyze the soil like satellite imagery, which should lower monitoring costs. Elias believes that if they’re able to create enough demand, the farmers will figure out a way to serve the market.
National Farmers Union spokesman Tom Driscoll endorses the plan, and believes farmers might be more receptive to generating alternative sources of income.
“There’s a lot happening to make farmers receptive to this type of market,” says Driscoll, including volatility in markets for global products, changing consumer demands, and extreme weather.
Good for Pocketbooks, Good for Soil
Carbon sequestration isn’t just a good thing for farmers’ pocketbooks. It’s also good for their soil. A recent study just published in March from the University of Nebraska has found that cover crops increase the organic particulate matter of soil and promote soil aggregation, which creates a greater potential to store carbon. The study was conducted by Julie McDowell, Sabrina Ruis and Humberto Blanco.
Cover Crops Help
The four year study was conducted on three sites in Nebraska. The group tried to determine how planting date and cover crop types could impact the soil organic carbon (SOC), organic matter concentration, and aggregation in corn and soybeans. Overall, the study found that the cover crops could improve soil aggregation and particulate organic matter concentration in the short-term, which could mean that cover crops could store soil carbon in the long term.
Restoring soil carbon has many benefits. It promotes aggregation of soil particles, helps the soil retain water, increases microbial activity, nutrient cycling and other important soil processes. It increases soil fertility and productivity. The amount of soil that can be sequestered in the soil is dependent on several factors, like soil type, management, elevation, and climate.
After carbon enters the soil, it’s more likely to remain there if there’s good soil aggregation and microbial activity. The addition of organic matter through residues is also helps keep that carbon in the soil by moderating the soil temperature. The United States has the highest potential of any country for soil carbon storage, so it appears that we may have a key role to play in the reduction of carbon in the atmosphere.