“It’s a very controversial space right now,” said Emily Oldfield, senior report author and agricultural soil carbon scientist at EDF, in an interview.
Why is this important: The Biden administration, much of U.S. business, and the international community are increasingly recognizing the potential of agriculture to reduce and sequester carbon dioxide and other greenhouse gases as part of a broader climate change mitigation strategy. 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 call on USDA to set standards so there is more clarity in the rapidly changing market. “There are a lot of variations and we need the USDA to play that role,” said Callie Eideberg, director of agricultural policy for EDF.
Eideberg predicted that the USDA likely won’t act in that space until the end of this year, or early 2022. The role the department will ultimately play is “everyone’s guessing,” he said. she declared.
How long does a carbon credit last: To understand the current variability between protocols, it is helpful to look at the permanence, or length of time that a landowner must commit to storing a ton of carbon dioxide in their soil – and out of the atmosphere – for count as a verified credit.
According to the Nori Croplands methodology, the tenure period is 10 years. According to one of Verra’s protocols, it’s 30 years. One of the protocols for the climate action reserve is 100 years, or part of it, according to the report.
How to estimate a carbon credit: Each of the protocols also has different ways of estimating the amount of carbon that is buried in the soil. Some require a combination of soil sampling and modeling; some stick only to sampling or modeling. If soil samples are required, some protocols stipulate how many should be taken and how often they should be taken, while others are not as specific, according to the report.
“We really want to make sure that a ton of CO2 is a ton of CO2 is a ton of CO2,” Oldfield said.
While this is fixed, reduce these emissions: The report recognizes that carbon sequestration remains an “uncertain approach” to climate change mitigation. The authors encourage a greater focus on the use of credits generated by reduced or avoided emissions, while policymakers are developing standards and funding more research to ensure confidence in carbon sequestration.
The report was funded by a grant to EDF from the High Meadows Foundation for postdoctoral fellowships and by the Bezos Earth Fund.