CDR Verification Framework Documentation
Docs: Component
Soil carbon impacts
Uncertainty
Adding ammendments like minerals or biochar to soils has the potential to induce changes to soil carbon, including by affecting pH or impacting plant or microbial activity. Theoretically, these impacts could increase or decrease soil organic carbon (SOC) storage (i.e. the priming effect). There is relatively little research on these potential interactions to date, and they merit further exploration. Due to the high uncertainty of these potential effects, we recommend this component not be included in the accounting of net carbon removal. If biochar application does increase SOC storage beyond the carbon embodied in the biochar, we recommend that these changes not be used to counterbalance project-related fossil CO₂ emissions nor counted as additional durable carbon removal due to the impermanence of soil carbon storage.
Applicable pathways
Pathway
VCL
Biochar
1-3
Revision history

Jun 29 2023
Fixed typo.

Apr 10 2023
Edited for cross-pathway consistency in response to the addition of the Biochar pathway.

Dec 19 2022
Second release. Edited component to reflect the possibility mineral weathering may also drive outgassing from soils. These edits occured as part of a broader update of the Enhanced Weathering pathway.

Sep 19 2022
First release.
Soil carbon impacts
Uncertainty
Adding ammendments like minerals or biochar to soils has the potential to induce changes to soil carbon, including by affecting pH or impacting plant or microbial activity. Theoretically, these impacts could increase or decrease soil organic carbon (SOC) storage (i.e. the priming effect). There is relatively little research on these potential interactions to date, and they merit further exploration. Due to the high uncertainty of these potential effects, we recommend this component not be included in the accounting of net carbon removal. If biochar application does increase SOC storage beyond the carbon embodied in the biochar, we recommend that these changes not be used to counterbalance project-related fossil CO₂ emissions nor counted as additional durable carbon removal due to the impermanence of soil carbon storage.
Applicable pathways
Pathway
VCL
Revision history

Jun 29 2023
Fixed typo.

Apr 10 2023
Edited for cross-pathway consistency in response to the addition of the Biochar pathway.

Dec 19 2022
Second release. Edited component to reflect the possibility mineral weathering may also drive outgassing from soils. These edits occured as part of a broader update of the Enhanced Weathering pathway.

Sep 19 2022
First release.