“It’s a very contentious space right now,” Emily Oldfield, lead author of the report and an agricultural soil carbon scientist at EDF, said in an interview.
Why it matters: The Biden administration, much of corporate America and the international community are all increasingly recognizing the potential for agriculture to cut and sequester carbon dioxide and other greenhouse gases as part of a broader strategy to mitigate climate change. But the potential will not be realized if the offset credits generated by agriculture are not seen as consistent or trustworthy.
A call to standardize: Green groups are calling for USDA to set standards so there’s more clarity in the rapidly changing market. “There’s a lot of variation and we need USDA to step into that role,” said Callie Eideberg, director of agricultural policy for EDF.
Eideberg predicted USDA would probably not take action in this space until closer to the end of this year, or early 2022. What role the department will ultimately play is “anybody’s guess,” she said.
How long a carbon credit lasts: To understand the current variability among the protocols, it’s helpful to look at permanence, or the length of time a landowner needs to commit to storing a ton of carbon dioxide in their soil — and out of the atmosphere — to count as a verified credit.
Under the Nori Croplands Methodology, the permanence period is 10 years. Under one of Verra’s protocols, it’s 30 years. One of the Climate Action Reserve protocols is 100 years, or some portion thereof, according to the report.
How to estimate a carbon credit: Each of the protocols also has different ways of estimating how much carbon is being sunk into soil. Some require a combination of soil sampling and modeling; some stick with only sampling or modeling. If soil samples are required, some protocols stipulate how many need to be taken, and how often they have to be pulled, while others are not as specific, according to the report.
“We really want to make sure a ton of CO2 is a ton of CO2 is a ton of CO2,” Oldfield said.
While this is sorted out, cut those emissions: The report acknowledges that carbon sequestration remains an “uncertain approach” to climate change mitigation. The authors encourage a greater focus on using credits generated from cut or avoided emissions while policymakers come up with standards and fund more research to ensure confidence on the carbon sequestration side.
The report was funded through a gift to EDF from the High Meadows Foundation for post- doctoral fellowships and through the Bezos Earth Fund.