Given the momentum behind carbon farming as a climate change mitigation strategy, we believe now is the time to establish clear standards that ensure that only real net changes in carbon receive financial rewards.
Carbon farming basics
As plants grow, they pull carbon from the atmosphere, and soil soaks it up and stores it. The amount of carbon stored varies significantly across soil type and climate.
Another climate-friendly strategy is raising livestock and crops together. Rotating cows among pastures allows grasses to recover from grazing, and the animals’ manure and the impacts of their grazing regenerate carbon in soils.
Carbon farming is also a potential revenue stream for farmers and ranchers, who can sell the credits they earn in carbon markets. Large-scale greenhouse gas emitters, such as manufacturers, purchase these credits to offset their own emissions.
Companies such as IndigoAg and Nori are already facilitating payments to farmers for carbon credits. And on June 24, 2021, the U.S. Senate passed the Growing Climate Solutions Act of 2021 by a vote of 92-8. The bill would authorize the U.S. Department of Agriculture to help farmers, ranchers and private forest landowners participate in carbon markets.
So far, however, there are no universal standards for measuring, reporting or verifying agricultural carbon credits. Here are the questions we see as top priorities.
This “solution” is virtually impossible to prove or disprove and yet “The closer you look at carbon farming, the more it comes to resemble a sweet deal between Big Ag and corporate America...while tapping into public money along the way.” @WIRED https://t.co/E0ppGsbk2w
One major challenge is that soils absorb varying amounts of carbon depending on depth, texture and mineral content. While certain practices increase carbon storage, quantifying how much is stored and for how long is critical for assigning dollar values to them. The markets and practices that work in different locations also vary widely.
Another priority is developing national minimum standards to predict and properly value soil carbon capture. Carbon may reside in soil anywhere from days to millennia, so time scale is an important consideration for markets. In our view, credits should reflect the duration carbon resides in soil, with full offsets generated only for longer-lasting storage.
We also believe that these programs must consider an operation’s net greenhouse gas emissions. For example, practices may store more carbon in soil but also increase emissions of nitrous oxide, another greenhouse gas.
Benefits and challenges
Rebuilding carbon-rich soil supports farmers’ bottom lines by improving soil health and increasing crop yields. But federal incentives could preferentially provide resources to big operations that have greater ability to sequester carbon on their vast acreage.
Ultimately, the goals of climate policy include curbing greenhouse gas emissions and actively removing carbon dioxide from the atmosphere. Before farmers receive soil carbon credits they can sell to offset other sources of emissions, we believe their value must be accurately assessed to ensure that society gets what it pays for.
This article has been updated to reflect that IndigoAg does not purchase carbon credits.
About Laura van der Pol, Dale Manning, Francesca Cotrufo and Megan Machmuller
Laura van der Pol is Ph.D Student in Ecology, Colorado State University.
Dale Manning is Associate Professor of Agricultural and Resource Economics, Colorado State University.
Francesca Cotrufo is Professor, Department of Soil and Crop Sciences, Colorado State University.
Megan Machmuller is Research Scientist, Colorado State University.