Improved Soil Management

This Protocol provides the requirements and procedures for the calculation of net carbon dioxide equivalent (CO₂e) removal from the atmosphere via improvements to soil organic carbon (SOC) stocks. In the context of this Protocol, we define SOC enhancement as the intentional adoption or intensification of land management practices that increase the accumulation of organic carbon within the soil profile, providing additional net carbon storage against a counterfactual baseline.

Soils represent the largest terrestrial carbon pool on Earth, storing an estimated 3,000 Pg of organic carbon¹. The potential for agricultural soils alone to contribute to climate mitigation is substantial: recent estimates suggest that improved cropland and grassland management could sequester between 0.28 and 0.43 Gt CO₂e yr⁻¹ globally², placing SOC enhancement among the most scalable nature-based climate solutions available. In addition to climate mitigation, improvements to SOC can provide a wide range of environmental and social co-benefits, including enhanced soil water retention and drought resilience, improved crop yields and long-term agricultural productivity, reduced fertilizer dependency, support for above- and below-ground biodiversity, and mitigation of erosion and nutrient runoff into waterways^{3, 4}. Despite these potential benefits, adoption of SOC-enhancing practices is frequently constrained by upfront implementation costs, limited access to agronomic expertise, and the absence of reliable financial incentives for farmers^5,6. Carbon finance presents a meaningful opportunity to address these barriers, enabling the climate mitigation potential of improved soil management to be realized alongside tangible co-benefits for land managers and local communities.

This Protocol applies to a wide range of land management practices capable of demonstrably increasing SOC stocks within agricultural and grassland systems. This Protocol is process-agnostic, focusing on verified outcomes rather than prescribed methods. Eligible Project activities encompass any practice that results in a net, sustained increase in SOC stocks against a counterfactual baseline.

This Protocol and its eligibility requirements are designed to ensure that all Project activities support the goal of durable climate mitigation and associated co-benefits, while excluding practices that may produce short-term apparent SOC gains without genuine long-term carbon storage.

This Protocol accounts for the quantification of the gross amount of CO₂ removed via net increases in SOC stocks, as well as all cradle-to-grave life-cycle Greenhouse Gas (GHG) emissions associated with project activities. This Protocol is developed to adhere to the requirements of ISO 14064-2: 2019 – Greenhouse Gases – Part 2: Specification with guidance at the project level for quantification, monitoring, and reporting of greenhouse gas emission reductions or removal enhancements.

The Protocol ensures:

• Consistent, accurate procedures are used to measure and monitor SOC stocks across the project area, utilizing direct soil sampling combined with validated modeling approaches to enable accurate accounting of net CO₂e removals;

• Consistent system boundaries and calculations are utilized to quantify net CO₂e removal, incorporating all material GHG sources and sinks within the project boundary;

• All net CO₂e removal claims are verified by an accredited third party;

• Project activities avoid harm to local ecosystems or biodiversity;

• Leakage impacts are quantified and appropriately addressed;

• Agreements with smallholder landowners and farmers, where applicable, are the result of a thorough engagement process and the terms help to support and advance local livelihoods;

• Removals are additional through the use of baseline approaches that integrate data on changing conditions and other guardrails set forth in the Isometric Standard;

• Comprehensive guidance on project design, soil sampling protocols, and monitoring mechanisms to confirm Durability and protect against Reversals, ensuring transparent Credit delivery.

This Protocol and all standardized approaches therein, including but not limited to the baseline, removal quantification, and the treatment of non-permanence risk, are informed by the best available scientific knowledge and have undergone external review by subject matter experts and relevant stakeholders. All comments received during consultation are publicly addressed, with revisions incorporated as appropriate, to ensure the certified version of the Protocol will yield high-quality Carbon Credits via rigorous, conservative, and appropriate methodologies.

Throughout this Protocol, the use of "must" indicates a requirement, whereas "should" indicates a recommendation.

This Protocol relies on and is intended to be compliant with the following standards and protocols:

• The Isometric Standard

• ISO 14064-2: 2019 - Greenhouse Gases - Part 2: Specification with guidance at the project level for quantification, monitoring, and reporting of greenhouse gas emission reductions or removal enhancements

Additional reference standards that inform the requirements and overall practices incorporated in this Protocol include:

• ISO 14064-3: 2019 - Greenhouse Gases - Part 3: Specification with Guidance for the verification and validation of greenhouse gas statements
• ISO 14040: 2006 - Environmental Management - Lifecycle Assessment - Principles & Framework
• ISO 14044: 2006 - Environmental Management - Lifecycle Assessment - Requirements & Guidelines

Additional principles that were considered in the development of this Protocol and aligned with, where feasible, include:

• The Core Carbon Principles of The Integrity Council for the Voluntary Carbon Market, v1.1, ICVCM, 2024
• Criteria for High-Quality Carbon Dioxide Removal, Carbon Direct & Microsoft, 2025
• Challenges and Opportunities in Soil Carbon Credits, Carbon Direct, 2025

Protocols and Methodologies that were assessed as part of a literature review during the development of this Protocol include:

• VM0042 Improved Agricultural Land Management, v2.2, Verra, 2025
• VMD0053 Model Calibration, Validation, and Uncertainty Guidance for Biogeochemical Modeling for Agricultural Land Management Projects, v2.1, Verra, 2025
• VT0014 Estimating organic carbon stocks using digital soil mapping, version 1.0, Verra, 2025
• US Soil Enrichment Protocol v1.1, Climate Action Reserve, 2022

This Protocol was developed based on the current state of the art, publicly available science regarding soil organic carbon improvement activities and MRV of improved soil management projects. This Protocol aims to be scientifically stringent and robust. We recognize that some requirements may exceed the status quo in the market and that there are numerous opportunities to improve the rigor of this Protocol. Key future improvements to the Protocol are outlined in Appendix A.

Additionally, this Protocol will be reviewed when there is an update to published scientific literature, government policies, or legal requirements which would affect net CO₂e removal quantification or the monitoring guidelines outlined in this Protocol, or at a minimum of every 2 years.

This Protocol aims to guide Projects that enhance soil organic carbon stocks through improved management activities in ways that support sustainable production, ecosystem services, and local livelihoods while remaining resilient to future climate scenarios. Projects must maintain or enhance ecological integrity. Where project interventions are implemented within working lands, The Project must support sustainable production within the landscape.

Project Proponents must provide a comprehensive description of all project activities and interventions to be implemented within the project boundary, and demonstrate, with reference to peer-reviewed scientific literature, the causal mechanism by which each intervention is expected to result in a net increase in soil organic carbon stocks.

This Protocol sets forth universal requirements for all Improved Soil Management Projects. All Projects are also subject to additional requirements tailored to the implementation practice(s) and setting of the Project Proponent’s soil management activities, and all Project Proponents must therefore select one or more of the following improved soil management intervention Modules, and demonstrate their reasoning for and capability to carry out the selected implementation practice(s) in the Project Design Document (PDD).

Project activities must not involve the conversion of native ecosystems, wetlands, or other high-conservation-value land to other uses. Project interventions also must not generate short-term apparent SOC gains at the expense of long-term soil health or biodiversity. Any inputs used within the project area, including biostimulants, biological inoculants, compost, or other amendments, must be applied in compliance with local regulation and disclosed to Isometric. Their associated life-cycle GHG emissions must be accounted for within the project boundary.

The geographic Project Boundary must encompass all areas where the Project Proponent is implementing SOC-enhancing management activities for crediting purposes. The Project Boundary may consist of a single area or a collection of discrete management areas. In the context of this Protocol, a discrete management area is the collection of one or more fields or land parcels subject to the same Project activities and management regime under the control of a single landowner or operator. Parcels within a discrete management area need not be physically contiguous. Sampling strata and monitoring units must be defined within the Project Boundary in accordance with the requirements set out in Section 8.0, and must be of sufficient resolution to capture meaningful spatial variation in SOC stocks across soil types, land use histories, and management zones.

Where land directly adjacent to the Project Boundary is under the management of the Project Proponent or an enrolled grower, and is subject to management activities with a plausible potential to influence SOC stocks within the Project Boundary (including tillage, application of organic inputs, or changes in vegetation cover at or near the boundary), those activities must be disclosed with justification and evidence that they do not pose a risk of Leakage or Reversal with respect to the enrolled area. This requirement is limited to land directly adjacent to the Project Boundary and does not extend to unenrolled fields elsewhere within a grower's operation.

This Protocol applies across the full temporal (see Section 5.0) and spatial scope of the Project. The Project Boundary is set at the time of project initiation and may be modified during the Crediting Period in the following circumstances:

• Addition of new fields or management areas. New fields or discrete management areas may be added to the Project Boundary during the Crediting Period, subject to the eligibility, baseline, and additionality requirements set out in this Protocol. Added areas enter the Project at the time of their addition and are subject to a Project Timeline reflecting that initiation date.
• Removal of fields or management areas. Fields or discrete management areas may be removed from the Project Boundary during the Crediting Period. Removed areas are treated in accordance with the unenrollment provisions of this Protocol, including the default assumption of a full reversal where ongoing monitoring is not maintained.
• Correction of boundary errors. Project Proponents may correct errors in field boundaries (for example, where grower-submitted boundaries require revision based on subsequent data review) without these corrections being treated as additions or removals, provided that: (i) the correction reflects a data-quality refinement rather than a substantive change to the enrolled area; (ii) the cumulative net effect of boundary corrections in any Reporting Period does not exceed 5% of the total enrolled area; and (iii) all corrections are documented, justified, and reported at verification.

All boundary modifications must be documented in the Monitoring Report and verified at the next Verification event.

The Project must not harm biodiversity or existing ecological function, and should aim to improve ecosystem function and biodiversity where possible.

The Project must not harm Indigenous Peoples and local, underserved, or marginalized communities, in compliance with the Social Impacts Section of the Isometric Standard and Section 6 of this Protocol. Where project activities occur on land owned, occupied, or customarily used by Indigenous Peoples, or where project activities have the potential to directly or indirectly affect the territories, resources, or livelihoods of Indigenous Peoples, Project Proponents must enact a Stakeholder Engagement Plan consistent with the principles of Free, Prior, and Informed Consent (FPIC) as outlined by the United Nations Declaration on the Rights of Indigenous Peoples. Project Proponents must document the impact assessment underlying their determination. Geographic proximity alone, in the absence of a plausible impact pathway, does not trigger this requirement.

The unit of enrollment, eligibility assessment, baseline determination, and quantification under this Protocol is the field, defined as a contiguous area of cropland under a single management regime. Project Proponents may enroll individual fields within a landowner's or operator's holdings without requiring enrollment of all fields under common ownership, lease, or operational control. References to "farm," "property," or "landowner" elsewhere in this Protocol should be interpreted at the field level unless the context expressly requires otherwise (for example, where legal tenure or contractual obligations are inherently held at the entity or parcel level).

Additionally, projects under this Protocol must meet all of the following project conditions:

• The Project must provide a net-negative CO₂e impact (net CO₂e removal) as calculated in the GHG Statement, in compliance with Section 9.

• The Project must be considered additional, in accordance with the requirements of Section 7.4.  

• The Project must meet the transparency requirements of this Protocol, outlined in Section 7.7.

The Project Commitment Period consists of the Crediting Period and any Ongoing Monitoring Period which is required by the Module under which The Project is crediting.

The Crediting Period is the interval between project initiation (e.g., first activity on site associated with the Project) and the end of the last Reporting Period. The Crediting Period is made up of successive Reporting Periods.

The Ongoing Monitoring period encompasses a period following the Crediting Period during which carbon stocks are monitored for potential reversals. Requirements for inclusion of an Ongoing Monitoring Period as part of the Project Commitment Period, as well as monitoring requirements, are covered at the Module level.

The Project Commitment Period is a project-level obligation held by the Project Proponent. Individual contracts between the Project Proponent and enrolled landowners or operators are not required to run for the full Project Commitment Period. Where individual contracts are shorter than the Project Commitment Period, the Project Proponent must demonstrate how monitoring and reversal liability for the affected enrolled land will be sustained for the remainder of the Project Commitment Period, including through the Ongoing Monitoring Period. An additional buffer pool contribution applies for Reporting Periods in which contracts are not in place for the full Project Commitment Period, in accordance with Section 10.4.1. For grouped projects where new fields are added to the Project over time, the Project Timeline may be staggered across enrolled fields to reflect different initiation times of Project activities.

Credit issuances occur throughout the Crediting Period and are issued upon verification of a Reporting Period. Under the cumulative accounting framework, credits issued at each verification event represent the cumulative net CO₂e removal from project initiation to the end of the current Reporting Period, less all credits previously issued under the Project and other discounts (e.g., leakage discount), in accordance with Section 9.0.

Abandonment of the Project or failure to perform the land management activities required to maintain SOC stocks at any point during the Crediting Period may result in project failure. In the event of project failure, all Credits issued under The Project will be canceled.

The duration of the Crediting Period, Reporting Period and Ongoing Monitoring Period, and Durability are defined at the Module level.

To ensure the Project Proponent has proper authorization from the true property ownership, this Protocol explicitly prohibits lessees or concessionaires from enrolling land for Credits without the landowner's signatory consent, which must be provided in the PDD.

For each enrolled area, the landowner or operator with rights of use over that area must have legal, documented land tenure for the duration of the Crediting Period applicable to that area. Where the Project Proponent is itself the landowner or operator, this obligation falls on the Project Proponent. Where the Project Proponent is contracting on land owned or operated by another party, this obligation falls on that landowner or operator, and the Project Proponent must document the underlying tenure as part of its enrollment evidence.

Tenure and contractual arrangements with individual landowners or operators are not required to extend to the full Project Commitment Period. Where they do not, the Project Proponent's project-level monitoring and reversal-compensation obligations continue to apply across the full Project Commitment Period as set out in Section 5.1 and Section 10, and an additional buffer pool contribution applies in accordance with Section 10.4.1.

Project Proponents are liable for the maintenance of the project system carbon stocks throughout the Project Commitment Period in accordance with the requirements of this Protocol and applicable Modules. Where the Project Proponent is contracting on land owned or operated by another party, including smallholder land, the landowner or operator must be contractually obligated to maintain the project system carbon stocks in accordance with the requirements of this Protocol and applicable Modules for the duration of their contractual participation in the Project.

• The Project Proponent and/or landowner(s) must provide documentation to verify their tenure, which could be demonstrated via legal agreements/contracts, tax records, notarized statements, and/or government records.

• In cases where all land is held by the government or in commons, or in cases where the land will be returned to the government during the Project Commitment Period, the Project Proponent must provide legal documents attesting to such land ownership structure and a legal agreement from the relevant authorities that project activities can be carried out for the length of the Crediting Period, and access will be granted during any Ongoing Monitoring Period.

• For land held in trust, the governing body must provide signatory consent for carbon credit enrollment.

• For land with multiple owners, all parties must give their signatory consent. Where extensive co-ownership structures (e.g., heirship land, undivided family interests, or analogous arrangements under local law) render universal signatory consent impracticable, the Project Proponent may instead demonstrate all of the following:

  • The operator enrolling the land holds documented, legally enforceable rights of use — through ownership, lease, usufruct, or equivalent — sufficient to direct land management activities for the duration of the Crediting Period applicable to that area;
  • Reasonable efforts have been made to identify and engage non-signing co-owners or rights-holders, including documented notification of project activities and a documented opportunity for them to raise objections, in accordance with Section 6.6.1; and
  • Any objections received from non-signing co-owners or rights-holders have been documented and addressed.
  • For areas with customary land tenure systems, Project Proponents may submit documentation or statements from local authorities or leaders.
  • The reversal risk arising from co-ownership fragmentation is addressed through the buffer pool framework in Section 10.4.

• The same alternative pathway set out above applies where land is enrolled by an operator under a leasehold or analogous tenure arrangement and signatory consent from the landowner is impracticable due to fragmented landownership, absent or unreachable landowners, or analogous circumstances. In such cases, the operator must demonstrate documented, legally enforceable rights of use sufficient to direct land management activities for the duration of the applicable Crediting Period, and must satisfy the engagement and objection-handling requirements set out above with respect to the landowner(s).

• In the event of land ownership transfer, including inheritance, sale, or other forms of succession, the Project Proponent should - subject to local, national, and regional laws - make every effort to ensure that the new owner(s) or heir(s) uphold the commitments outlined in the land agreement. This includes maintaining the system carbon stocks in accordance with the requirements of this Protocol and applicable Modules, and upholding any other project requirements for the duration of the Project Commitment Period. If land area is unenrolled as a result of transfer of ownership, then the requirement for ongoing monitoring in Section 5.1.1.1 must be upheld.

Monitoring for Reversals is the responsibility of the Project Proponent throughout the Project Commitment Period. Loss of land access through unenrollment or other means does not extinguish the Project Proponent's monitoring obligation; where direct measurement is not possible for a given enrolled area, the Project Proponent must either secure equivalent remote and modeled monitoring sufficient to characterize reversal risk for that area, or treat the area as having experienced a full Reversal. For example remote sensing as a screening layer to detect surface-visible reversal triggers (including land use change, tillage events, fire, and major erosion), ideally coupled with sampling or modelling.

Credit issuances may decrease over time, and continued financial payments may be needed to incentivize maintenance of carbon stocks. To evidence the continued financial viability of the Project over the full Project Commitment Period, Project Proponents must provide a financial model and cash flow statement demonstrating a clear payment structure for the duration of the Project Commitment Period. Methods to maintain continued financial incentives may include, but are not limited to:

• Revenue or subsistence benefits from commodity production occurring within the project system; and/or

• Investing a portion of revenue into a trust which shifts payments over the full Project Commitment Period.

If operational, legal, or regulatory constraints preclude the development of a financial model or negate its efficacy for supporting long-term maintenance, the Project Proponent must provide justification for the absence of a financially-based plan for long-term maintenance, as well as details of what alternative mechanisms will be in place to support maintenance of the Project carbon stocks over the full Project Commitment Period. Such mechanisms may include, but are not limited to, conservation easements, governmental protections, or land trusts.

Following the Isometric Standard, Credits issued under this Protocol are contingent on the implementation, transparent reporting, and independent Verification of comprehensive safeguards. These safeguards encompass a wide range of considerations, including environmental protection, social equity, community engagement, and respect for cultural values. The process mandates that safeguard plans be incorporated into all major project phases, with detailed reports made accessible to stakeholders. Adherence to and verification of environmental and social safeguards is a condition for all Crediting Projects.

An environmental and social risk assessment, in compliance with the Environmental and Social Impacts Section of the Isometric Standard, must be completed to identify potential risks, followed by the development of tailored mitigation plans. These plans must encompass specific actions to avoid, minimize or rectify identified impacts. Effective implementation of these measures must also be accompanied by a robust monitoring plan to detect adverse effects and pause project activities if necessary, using the principles of adaptive management described below.

Environmental and social risk identification, assessment, avoidance, and mitigation planning will be unique to the technical, environmental, and social contexts of the Project. To accommodate this variation, the requirements outlined in this section serve as minimum safeguards to which the Project Proponent and Isometric can add to on a case by case basis, to be included in the PDD, if applicable.

Project Proponents must comply with all national and local laws, regulations and policies, and receive any necessary permits for project activities, if applicable. Where relevant, projects must comply with international conventions and standards governing human rights and uses of the environment.

Project Proponents must document activities that trigger environmental permitting requirements.

Where Projects aim to apply new or novel technologies such as biostimulants, Project Proponents must document activities that trigger environmental permitting requirements. This is to include, at a minimum:

1. Demonstration that any product has approval, or is registered with a regulatory authority where required by national legislation.

2. Demonstration that the use within the context of the project does not have any adverse effect on soil, plant, human or animal health and the surrounding environment, both after application to the soil and during storage and handling.

3. Where the product is being relied upon as an SOC-enhancement intervention for the purposes of crediting, demonstration through scientific literature appropriate to the product and project context of a credible mechanism by which the product could contribute to SOC stock gains. This requirement does not apply where the product is deployed for agronomic purposes (such as crop stress tolerance, pest management, or nutrient cycling) and any contribution to SOC is incidental to its primary use.

Adaptive management incorporates learnings and takeaways from project monitoring into project development⁷. Regular data collection and sharing is necessary to implement adaptive management. Results from data collection at the end of each Reporting Period must be shared with local stakeholders, as described in Section 6.6.1, and be used to inform future iterations of project management and development.

Project Proponents are required to predict and plan for potential unintended but foreseeable outcomes of project activities and construct mitigation plans for such instances. Foreseeable risks identified during the preparation of the environmental and social risk assessment must be included in the PDD and the following must be detailed for each potential risk:

• A region specific mitigation plan
• The measured or observed outcome that will trigger the mitigation plan
• Plan for information sharing
• Emergency response plan, if applicable

The Project should not hinder the ability of the community or local ecosystem to adapt to climate change as a result of the CDR activity.

Projects must maintain and should enhance the biodiversity of existing ecosystems while optimizing carbon storage outcomes, regardless of whether the project interventions involve a change in land use. Some projects under this Protocol may be established in working landscapes where existing species assemblages, soil communities, and ecological processes are already present. The primary biodiversity objective for these projects is to ensure that land management practice changes designed to enhance soil carbon sequestration and storage do not compromise the ecological integrity of these established land uses, and where possible, enhance biodiversity through improved soil health, vegetation diversity, and habitat complexity.

SOC-enhancing practices can provide significant opportunities to enhance biodiversity by improving soil biological diversity, increasing vegetation cover, supporting pollinator habitat, and reducing agrochemical inputs. However, these same practices must be carefully designed to avoid unintended consequences such as introduction of invasive species, disruption of existing soil communities, or habitat degradation arising from changes in water management or agrochemical use.

• Project Proponents must not implement land management practices that result in net degradation of soil biological diversity, and must demonstrate adherence to this requirement in the Project Design Document. For all project interventions, the Project Proponent must provide evidence (peer-reviewed literature, project data, or equivalent) demonstrating that the implemented practice does not pose a threat of net degradation to soil biological diversity, and must demonstrate adherence to this requirement in the Project Design Document. If no such evidence exists, Project Proponents must provide additional details on how the system health will be monitored over the course of The Project.

Additionally, Project Proponents must demonstrate that proposed management practice changes will maintain existing biodiversity and, where possible, contribute to measurable improvements in ecosystem function and resilience as further described in the requirements below.

Project Proponents must list all plant species introduced as part of project activities in the Project Design Document. Introduced species must be native, naturalized, or non-native range-expanding species appropriate to the project area. Project Proponents must not introduce or maintain species invasive to the region or similar climates, geographies, or ecosystems of the project area.

Where non-native species are introduced as part of project activities (e.g., non-native cover crop species), Project Proponents must demonstrate that:

• The species do not have the potential to become invasive, evidenced through peer-reviewed literature or observational studies from the same region or regions with similar climates, geographies, and ecologies; and
• The species will serve a functional role consistent with the ecological context of the project area (e.g., as a nitrogen-fixing cover crop or pollinator resource), and that its introduction is not expected to materially disrupt nutrient cycling regimes, pollinator resource availability, soil microbial communities, or other ecological functions of the project area or surrounding landscape, beyond the effects intended as part of the project intervention.
• The level of evidence required is proportionate to the species and context: species with extensive regional deployment history and well-characterized ecological behavior may rely on existing peer-reviewed literature and observational evidence, while species without such deployment history must be supported by site-specific or analogous evidence sufficient to characterize the relevant ecological risks.

The definition of 'invasive species' in this Protocol is consistent with the Convention on Biological Diversity's definition of Invasive Alien Species, being a "species whose introduction and/or spread threatens biological diversity”⁸.

Project Proponents must provide due diligence to avoid harm to rare, threatened, and endangered species in the project area, as well as preventing against new species added to this list as a result of project activities. A review of rare, threatened, and endangered species must be included and referenced in the Project Design Document.

The list must be developed using the following sources in order of priority:

• Local and regional registries;

• National registries;

• Peer-reviewed publications; and

• The IUCN Red List of Threatened Species, where the designation of Vulnerable (VU) shall be considered Threatened and Near Threatened (NT) shall be considered Rare.

For each rare, threatened, or endangered species identified, the Project Proponent must document in the Project Design Document:

• Ecosystem services vital to the ecology and population stability of the species in the project area;

• How the project will maintain or enhance these ecosystem services throughout the Project Commitment Period; and

• A population monitoring plan where project activities pose an identified risk to the species.

Project Proponents must handle data and information related to rare, threatened, and endangered species with discretion, particularly in regions with histories of poaching, over-harvesting, or other elevated threats.

Any use of synthetic herbicides or fertilizers as part of project interventions must be reported to Isometric.

Any use of synthetic pesticides must be targeted and limited in scope towards the targeted pest(s) or insect(s), be thoroughly justified and reported immediately to Isometric.

All uses of chemical amendments must adhere to BMPs as well as all local, state/provincial, and national laws and regulations regarding their use. The following reporting is required of all projects using chemical amendments:

• Any planned use within the Project Area must be reported in the PDD at project initiation. Any updates to these activities over the project lifetime must be reported during subsequent verifications.

• Project Proponents must identify the BMPs and/or laws and regulations, and describe how they will conform in the PDD.

The emissions associated with any use of synthetic herbicides, fertilizers, and pesticides must be accounted for in line with the emissions accounting requirements of Section 9.5.

In accordance with the Stakeholder Input Process Section of the Isometric Standard, Project Proponents must demonstrate active stakeholder engagement throughout project planning and operation, ensuring that all risk mitigation strategies contribute to sustainable project outcomes. Local stakeholders may contribute an in-depth understanding of the project area and operations, and provide invaluable insights and recommendations on potential risks, necessary safeguards and specific monitoring needs. Engaging local stakeholders in projects creates community buy-in, providing long-term commitment and investment in the success of nature-based projects^{9, 10}. Furthermore, lack of community support, stakeholder engagement, and perceived community benefits has been identified as a primary source of project failure in previous nature-based projects¹¹.

The Project Proponent must develop a Stakeholder Engagement Plan in accordance with the requirements outlined in the Stakeholder Input Process Section of the Isometric Standard. The plan and supporting documentation, including evidence of meetings or other forms of engagement, must be submitted in the PDD.

Prior to the commencement of project activities, Project Proponents must assess whether Indigenous Peoples will be impacted by project activities. Impacts may include, but are not limited to:

• Project activities that occur on land or territories that are owned, occupied, or utilized by Indigenous Peoples, regardless of whether or not this claim is recognized by the local governing body or held by rights to self-determination, as recognized by the United Nations;
• Project activities that will affect natural resources necessary for the livelihoods or cultural rights of Indigenous Peoples.

This assessment must incorporate analysis of reputable, independent data by a subject matter expert, who may be a third party. The results of this assessment must be included in the PDD. If the assessment identifies potential impacts to Indigenous Peoples, the Project Proponent must enact a Stakeholder Engagement Plan consistent with the principles of Free, Prior, and Informed Consent (FPIC) as outlined by the United Nations (UN) Declaration on the Rights of Indigenous Peoples¹² in 2007 and expanded upon by the Food and Agriculture Organization of the United Nations in 2016¹³, and the additional requirements in Section 6.6.1.2 apply.

Where the assessment does not identify potential impacts on Indigenous Peoples, Project Proponents are encouraged, but not required, to complete a Stakeholder Engagement Plan consistent with FPIC principles, particularly where other relevant stakeholders rely on land or resources located within the project area.

The following information from the stakeholder engagement process must be made publicly available, with personal information anonymised or redacted to protect stakeholders, project personnel, and project outcomes:

• Due diligence that the stakeholder engagement processes were carried out (e.g., meeting recordings or copies of information shared with stakeholders);
• The structure of revenue sharing arrangements, including the percentage of revenue allocated to each documented party (Project Proponent, enrolled landowners, insurance providers, and other parties listed in the PDD), and the eligible forms of revenue sharing.

Absolute revenue figures, individual transaction values, and buyer-specific pricing are not required to be made publicly available under this Protocol. Where the Isometric Standard or this Protocol requires Project Proponents to report financial information to Isometric for verification or oversight purposes, that information may be submitted in confidence and is not subject to public disclosure unless expressly required elsewhere in this Protocol.

Where the impact assessment in Section 6.6.1.1 identifies potential impacts on Indigenous Peoples, the Project Proponent must enact a Stakeholder Engagement Plan consistent with the principles of Free, Prior, and Informed Consent (FPIC) as outlined by the United Nations Declaration on the Rights of Indigenous Peoples in 2007 and expanded upon by the Food and Agriculture Organization of the United Nations in 2016.

FPIC is a governance mechanism, not an informational disclosure process. The requirements of this section are intended to ensure that affected Indigenous Peoples have a substantive role in shaping project design and the genuine ability to grant, condition, or withhold consent, not merely to receive information about decisions already made.

The FPIC principals are as below:

• Free: Stakeholders are not subject to intimidation, coercion or manipulation during the decision making process.

• Prior: Engagement is sought in the early stages of project development before commencement of project activities. Consent must be sought as part of project development, regardless of local requirements. The timeline for the decision making and deliberation periods is set in consultation with all stakeholder groups and is informed by customary, local, and/or traditional practices.

  • The stakeholder engagement process must be enacted early in the project development process, prior to the initiation of Project activities. The stakeholder engagement schedule must be circulated prior to project initiation, and with enough notice to engage stakeholders in the planning processes. In some instances, Project Proponents that initiated project activities prior to engaging with Isometric and did not engage Indigenous Peoples stakeholders under the principles of FPIC may still be eligible for crediting under this Protocol, in consultation with Isometric, by demonstrating how stakeholder engagement will be incorporated into future project planning.

• Informed: Information is presented in a manner that is accessible to all stakeholder groups. Accessible content may differ across stakeholder groups. The Project Proponent must consider in the information sharing process the language and medium of communication. For example, if information is presented electronically, stakeholders must have access to and familiarity with the necessary technology to review the information. If information is presented during in-person meetings, the meetings must be held at a time and in a location that is conducive to stakeholder attendance. Information presented to stakeholders must be objective and present trade-offs fairly and accurately. Finally, information must be provided on an ongoing basis. The following due diligence is strongly recommended to ensure stakeholder groups are well informed of project development and outcomes:

  • Stakeholders should be made aware of the value of the Credits, and anticipated revenue of the Project at-large. The Project’s anticipated growth and issuance should be modeled, and simulations describing the value of Credits at current market prices should be made clear to proponents.
  • Stakeholders should have full access to The Project’s finances, budget, and forecasted returns.
  • Stakeholders should be aware of alternative land-use/land management scenarios.
  • Stakeholders should be aware of how changes in management practices might affect expected yields within existing productive areas.
  • Stakeholders should have a clear understanding of the breakdowns in project income expenditure, and a clear understanding of the precise percentage of revenue that they are entitled to.

• Consent: Must be freely given and may be withdrawn. Consent may be conditional upon milestones in project development or the emergence of new information. Stakeholder consent is not guaranteed as a result of the Stakeholder Input Process.

The Project Proponent is encouraged to prepare alternatives for the withdrawal or denial of consent to project activities by stakeholder groups.

The following may serve as burdens of proof that the Stakeholder Input Process conforms with the principles of FPIC. The Project Proponent must indicate how these steps in the stakeholder engagement process were or will be carried out during the project lifetime. Multiple rounds of stakeholder engagement may take place during a project lifetime, as needed. The Project Proponent may identify other burdens of proof demonstrating that the principles of FPIC have been observed and submit them in the PDD in addition to, or instead of, those below, in consultation with Isometric.

• Measures taken to effectively reach (i.e., identify and locate) all stakeholder groups. If the Project Proponent is not able to reach all adult community members, the percentage of adults in the community reached must be included in the PDD, as well as proof of the attempt to reach the remaining community members. The majority of adult community members must be successfully reached to be eligible for crediting under this Protocol.

• The manner in which information was presented to stakeholders, including the medium and language.

• How stakeholder input was obtained, including the medium and language.

• How stakeholder input was incorporated into the project design.

The VVB may conduct random surveys or interviews with stakeholder groups, and/or witness some or all of the processes described above.

Additional requirements apply to any projects which operate via partnerships with smallholder landowners. We note that there is no standard definition of the term smallholder, and the land area of such properties can be variable across the globe¹⁴. In the context of this Protocol, landowners are considered to be individuals who hold rights to the land and play a primary role in management activities occurring within the land. Projects which operate via a collection of separate land agreements which are held directly with such landowners will be considered to be operating via a smallholder arrangement and subject to the following requirements. Project Proponents must follow the same stakeholder engagement plan and principles of FPIC described in Section 6.6.1 for all enrolled landowners.

It is vital that enrolled landowners understand the contracts they are entering into as part of the Project. As part of this stakeholder engagement and FPIC process, Project Proponents must disclose the following to enrolled landowner(s) and ensure that these landowner(s) understand:

• Financials, including: revenue sharing arrangement, the anticipated value of the carbon Credits, and the anticipated earnings of The Project.
• Carbon Markets, including: the volatility of the carbon market and that the sale of carbon Credits is not guaranteed.
• Project Crediting, including: the concept of counterfactuals, and the unpredictability of carbon storage and loss overtime — Credits may be less than anticipated under ex-ante projections.
• Monitoring, including: that their land is may be monitored via satellite imagery as required by this Protocol and related Modules, and that this data — as well as geospatial information related to their land — will be anonymized and shared with the public through the Isometric Registry.
• Geospatial information and other data that must be publicly shared by enrolled landowners includes remote-sensing maps and imagery that document the Project’s carbon stocks, structure, and ecological benefits.
• Data Sharing Practices, including: what data will be shared with different parties (e.g., Isometric, public, government bodies, etc.), how data collected from their land will be used, Project Proponent data security procedures, and data ownership.

Project Proponent must disburse a minimum of 20% of the revenues generated from Credits issued under the Project to enrolled landowners over the lifetime of the Project unless a different threshold is defined by the intervention Module.

Eligible forms of revenue sharing include:

• Direct payments (may include lease payments for land access by the Project)
• Planting materials (e.g., seedlings, fertilizer)
• Equipment and/or infrastructure
• Training (costs to conduct the training)

All of these must be provided to landowners at an individual level and any non-monetary, in-kind components must involve a transfer of ownership to the landowner. If any of these are contingent upon the landowner meeting particular requirements (e.g., maintenance of system), those requirements must be clearly communicated to landowners at the time of the initial agreement and disclosed in the PDD. At PDD submission, Project Proponents must provide details of the systems which will be used for benefit distribution and the documentation which will be produced for tracking distribution (e.g., digital payment records, other documentation in absence of formal financial systems). These systems must also include a mechanism for landowners to report any grievances or disputes related to revenue sharing and for the tracking of the response and resolution of these issues.

Project Proponents must provide an anticipated timeline of how revenue sharing will be distributed over the duration of the Project in the PDD. At every verification, Project Proponents must provide evidence demonstrating progress on the revenue sharing plans, including proof of payments and benefit distribution, and report any grievances raised by landowners via the reporting system and subsequent responses and resolution by the Project Proponents. Projects which fail to provide sufficient evidence and/or reporting may be required to undergo an audit by an independent certified financial auditor. If at any verification the cumulative revenue sharing has fallen >20% below the level at which it was projected to be at for that time in the initial plan at PDD submission, the Project Proponent must submit an updated revenue sharing plan and timeline to demonstrate how the Project will meet the revenue sharing required by this Protocol and their agreements with landowners. This revised plan will be used as the benchmark for subsequent verifications.

Revenue sharing percentages must be made public, including the percentage of revenue or Credits allocated to each documented party (e.g., Project Proponent, enrolled landowner(s), insurance provider(s), and other documented parties listed in the PDD). This requirement applies to the structure and proportions of benefit sharing; absolute revenue figures, individual transaction values, and buyer-specific pricing are not required to be made publicly available.

Project Proponents must also disclose within the PDD what training and/or assistance will be provided to enrolled landowners to support proper management of the project system and implementation of project interventions. These plans should be informed by engagement with the enrolled landowners, and address any needs or risks that are identified through this process.

The Project Proponent must identify and develop processes for the protection and promotion of community well-being in the PDD, as follows:

• Protection of human rights:

  • Policies and practices upholding anti-discrimination on the basis of gender, sexual orientation, etc.

• Grievances, feedback, and complaints:

  • The process by which the Project Proponent accepts grievances, feedback, and complaints. Project Proponents must provide details on how adjudication and oversight will be supported with third parties. The grievance redress process must be outlined in the PDD.

  • Mediation and resolution process for grievances and complaints.

• Employment Opportunities:

  • Hiring practices and policies, including the number of short-, medium-, and long-term employment opportunities that were directly created (or expected to be created) via project activities. The Project Proponent must also report how many of these employment opportunities were/will be recruited for in the local community.

As previously mentioned, community buy-in is critical to the success of improved soil management projects. Community buy-in may be established when stakeholders are properly informed about the benefits they can expect from the Project. Equally important in maintaining buy-in is for the positive impacts resulting from the Project to match the (perception of) potential benefits presented to community stakeholders at the project onset. A mismatch in benefits expected and benefits realized may similarly hinder project success.

While this Protocol will not prescribe requirements for community impacts, the Project Proponent is strongly encouraged to consider establishing the following programs and activities:

• Employment opportunity programs favoring local community members, especially in the creation of long-term jobs;

• Establishment of community benefit-sharing arrangements;

• Construction of infrastructure, such as roads, that are accessible to the community;

• Establishment of programs to support training in sustainable land management practices;

• Development of site specific mitigation plans for potential negative community impacts.

Positive impacts should be felt by all stakeholder groups identified in Section 6.6.1. Project Proponents should consider which groups may face the brunt of negative community impacts, and how positive community benefits may be shared equitably with these and other marginalized groups.

It is recommended that the Project Proponent provide support to the local communities and ecosystems to establish region-specific mitigation strategies to adapt to changing climates.

The following topics are covered briefly in this Protocol due to their inclusion in the Isometric Standard, which governs all Isometric Protocols. See in-text references to the Isometric Standard for further guidance.

For each specific Project to be evaluated under this Protocol, the Project Proponent must document project characteristics in a Project Design Document (PDD) as outlined in the Documentation Section of the Isometric Standard. The PDD will form the basis for project validation and evaluation in accordance with this Protocol.

Projects must be validated and net CO₂e removals verified by an independent third party, consistent with the requirements described in this Protocol and the Module(s) under which the Project is crediting, as well as in the Validation and Verification Requirements Section of the Isometric Standard.

The Validation and Verification Body (VVB) must consider the following requisite components:

• Verify that The Project meets the Applicability conditions described in Section 4

• Verify that the Environmental & Social Safeguards outlined in Section 6 are met

• Verify that the System Boundary & Leakage assessment adheres to the requirements of Section 8

• Verify that the quantification approach and monitoring plan adheres to requirements of Section 9

• Verify that the conditions for ensuring durability and monitoring for Reversals in Section 10 are met

• Verify that the Project is compliant with requirements outlined in the Isometric Standard

As part of this evaluation, the VVB must also review the characterization and quantification of all individual uncertainty sources within the listed components that contribute to the calculation of net CO₂e removal.

The threshold for Materiality, considering the totality of all omissions, errors and misstatements, is 5%, in accordance with the Materiality Threshold Section of the Isometric Standard.

Verifiers should also verify the documentation of uncertainty of the GHG Statement as required by the Uncertainty in Removals and Reductions Section of the Isometric Standard. Qualitative Materiality issues may also be identified and documented, such as:

• Control issues that erode the verifier’s confidence in the reported data;

• Poor management documented information;

• Difficulty in locating requested information; and

• Noncompliance with regulations indirectly related to GHG emissions, removals or storage.

Project Validation and Verification must incorporate site visits to Project facilities, namely in situ field plots, in accordance with the requirements of ISO 14064-3, 6.1.4.2. This is to include, at a minimum, site visits during the first Validation or Verification of a Project, to the project site(s). Validators should, whenever possible, observe project operation to ensure full documentation of process inputs and outputs through visual observation and validation of instrumentation, measurements, and required data quality measures.

A site visit must occur at least once during each Project Validation. Additional site visits may be required if there are substantial changes to field operations over the course of a Project's Validation period, or if deemed necessary by Isometric or the VVB. Site visit plans are to be determined according to the VVB's internal assessment, in consultation with Isometric.

Verifiers and Validators must comply with the requirements defined in the Validation and Verification Requirements Section of the Isometric Standard. In addition, verification teams must maintain and demonstrate expertise associated with land management practices and soil science, including both field measurements processing and analysis and model-based analysis. Verification teams must also demonstrate competence in assessing stakeholder engagement processes.

CDR via soil sequestration is a result of a multi-step process (e.g., site preparation, land management activities, system maintenance, monitoring), with activities in each step potentially managed by a different operator, company, or owner. Further, improved soil management projects can also often involve a coalition of smallholder landowners. A single Project Proponent must be specified contractually as the sole owner of the Credits when there are multiple parties involved in the process, and to avoid Materiality of net CO₂e removals. Contracts must comply with all requirements defined in the Ownership Section of the Isometric Standard.

The Project Proponent must be able to demonstrate additionality through compliance with the Additionality Section of the Isometric Standard. The Baseline scenario and Counterfactual utilized to assess additionality must be project-specific and comply with Section 9.4.

Projects must not occur in regions where significant rates of the project interventions are driven by market demand, local and/or national incentives, or policies that would lead to similar land management practices without Carbon Finance.

For projects where the Project Proponent is not the land owner, the landowners, land managers, or authorized (with documentation) representative thereof must provide signed attestations confirming that implementation of the relevant project activities was contingent upon participation in the Project.

Government subsidies or civil contractual obligations for specific land management practices, such as organization bylaws, inhibit additionality and fall under the Regulatory criteria in the Additionality section of the Isometric Standard. Additionality is assessed each Reporting Period using the counterfactual assessment described in Section 9.4.

All projects must demonstrate the necessity of Carbon Finance for project viability following the Additionality Section of the Isometric Standard. If any revenue will be produced from commodity production within the project area or sources other than Removals, additional requirements for demonstrating financial additionality are described in Financial Additionality Considerations Section of the Isometric Standard.

The Project must document that the relevant project activities have not been implemented on participating sites prior to enrollment. The project must complete a prior-adoption lookback :

• Default**:** 5 consecutive years of non-adoption for the relevant project activities immediately preceding the project start date.

• Trial**** exception**:** A single year of adoption within the lookback is permissible if the Project Proponent demonstrates continuous non-adoption across an extended 7–10 year window. Two or more years of adoption (consecutive or not) within the extended window disqualifies the field.

• Management**-change** exception**:** Where documented arm's-length management change has occurred within the 5-year window (new owner, new tenant), the lookback is reduced to 3 consecutive years of non-adoption under the new management, provided the new manager has not previously practised the intervention on the enrolled field.

Financial Additionality must be reconsidered at Crediting Period renewal, in accordance with the requirements in this section. Projects must select one of the following options to meet ongoing Financial Additionality:

1. Continued validity of existing Financial Additionality demonstration
2. Reassessment of Financial Additionality

If a review indicates the Project has become non-additional, the Project will be ineligible for future Credits. Current or past Crediting Periods will not be affected.

Where a Project’s existing Financial Additionality demonstration was conducted over a defined investment horizon, the existing Financial Additionality determination remains valid up to the end of that investment horizon, provided the Project can demonstrate that key economic and operational assumptions used in the original demonstration remain materially unchanged. Projects which continue under an existing Financial Additionality determination in this way may only do so until the end of the investment horizon considered in the original determination, and must reassess Financial Additionality at the first verification event following the end of the existing investment horizon period.

Reassessment of Financial Additionality is required if any of the following conditions apply:

1. The renewal date occurs after the originally defined investment horizon;
2. A new investment or continuation decision is necessary to continue project crediting activities; and/or
3. Material changes to market conditions, regulatory requirements or project operations have occurred such that the original assumptions are no longer valid.

Where reassessment is required in accordance with the above requirements, the Project Proponent must demonstrate that continued Carbon Finance remains necessary to continue project crediting activities, by conducting a full Financial Additionality assessment against the updated Project and baseline scenarios.

The following steps must be taken to demonstrate that without Carbon Finance the project activity is not Common Practice, in accordance with the requirements defined in the Common Practice Analysis Section of the Isometric Standard.

1. Define the project activity (e.g., no tillage).
2. Identify the applicable geographic area, as described in the Common Practice Analysis Section of the Isometric Standard.
3. Identify a similar class of adopters or landowners (e.g., smallholder farmers, community-held land, private concessions).
4. Identify and explain any essential distinctions between the proposed Project and similar activities, as described in the Common Practice Analysis Section of the Isometric Standard.
5. Assess the market penetration rate using either a) a survey-based approach, or b) relevant data from existing literature, as follows:

a) Survey-based approach:

• Survey a representative sample of similar landowners from within the relevant geographic domain within five years of the project start date.

• Calculate the cumulative market penetration rate (as an area percentage) of the project activity by landowners who have not received Carbon Finance revenue (e.g., are neither part of a registered Isometric Project, nor registered under other GHG programs) in the sample of adopters.

b) Data from existing literature: Statistics on land management activities derived from data collected within five years of the project start date may be used for this demonstration, provided they are relevant to the project area, do not distinguish between activities incentivized by and not incentivized by Carbon Finance (thus are conservative), and are publicly available as:

• agricultural census, survey or other government data;

• peer-reviewed scientific literature; or

• independent research or reports, with full and transparent methods and documentation of results.

In accordance with the Common Practice Analysis Section of the Isometric Standard, the proposed Project activity is considered to demonstrate Common Practice additionality where the market penetration rate is below or equal to 20% on an acreage basis.

If the overall adoption rate for the practice in the geographic area exceeds 20% on an acreage basis, The Project may demonstrate Common Practice additionality if they can evidence that:

1. The market penetration rate for the activity is below or equal to 20% on fields with similar cropping rotations and irrigation infrastructures, or
2. The market penetration rate for the activity is below or equal to 50%, but evidence can be provided that the adoption rate has fallen by at least 10 percentage points over the prior decade as measured by USDA Census of Agriculture publications or equivalent reporting in other jurisdictions.

Projects aiming to implement multiple practices within each geographical area, must demonstrate the penetration rate of each practice individually is less than 20% according to the criteria outlined above.

The 20% adoption rate for a practice should control for adoption funded or motivated by other incentives or programs. The following acre categories should be subtracted from adoption rate in the geographic area according to procedures above to yield the net adoption rate:

• Acres enrolled in any private-market carbon credit program for the relevant practice.
• Acres under any per-acre incentive program paying > $5/acre for the relevant practice.
• Acres under USDA EQIP/CSP contracts (or equivalent government conservation programs) that specifically name the relevant practice.

For example, if in a geographic area the gross adoption rate for a practice is 35%, but 20% of that adoption is due to enrollment in alternative carbon credit programs, and a USDA conservation program, the net adoption rate is 15% and The Project is deemed additional from a common practice standpoint, all else equal.

The uncertainty in the overall estimate of the net CO₂e removal as a result of the Project must be accounted for. The total net increase in CO₂e removed for a specific Reporting Period, CO₂e_Removal,RP, must be conservatively determined in accordance with the requirements outlined in the Uncertainty in Removals and Reductions Section of the Isometric Standard.

Projects must report a list of all key variables used in the net CO₂e removal calculation and their individual uncertainties, as well as a description of the uncertainty analysis approach, including:

• field measurements used for the net CO₂e removal calculation

• parameters that impact the estimation of the soil organic carbon content, such as bulk density, etc.

• emission factors utilized, as published in public and other databases used

The uncertainty information should at least include the minimum and maximum values of each individual variable. More detailed uncertainty information should be provided if available, as outlined in the Uncertainty in Removals and Reductions Section of the Isometric Standard.

In addition, a sensitivity analysis that demonstrates the impact of each input parameter’s uncertainty on the final net CO₂e uncertainty must be provided. Variables may be omitted from the sensitivity analysis if they are already being included in the uncertainty analysis. Details of the sensitivity analysis method must be provided such that a third party can reproduce the results. Input variables may be omitted from an uncertainty analysis if they contribute to a < 1% change in the net CO₂e removal. For all other parameters, information about uncertainty must be specified.

In accordance with the Isometric Standard, all evidence and data related to the underlying quantification of CO₂e removal and environmental and social safeguards monitoring will be available to the public through the Isometric platform. That includes:

• Project Design Document

• GHG Statement

• Measurements taken, with supporting documentation (e.g., calibration certificates)

• Emission factors used

• Scientific literature used

• Proof of approval for necessary permits

• Remote sensing and/or field plot data collected by The Project

• All data and methodological details used for the baseline calculation

• Model specifications and output

The Project Proponent can request certain information to be restricted (only available to authorized Buyers, the Registry, and VVB) where it is subject to confidentiality. This includes emission factors, specific data, and/or proprietary models from licensed databases. Restrictions can also be requested when working with smallholder landowners when it is necessary for protecting landowner privacy. However, all other numerical data produced or used as part of the quantification of net CO₂e removal will be made available.

The scope of this Protocol includes GHG sources, sinks and reservoirs (SSRs) associated with an improved soil management project.

A cradle-to-grave GHG Statement must be prepared encompassing the GHG emissions and removals relating to the activities outlined within the system boundary.

GHG emissions and removals associated with the Project may be direct emissions from a process, or indirect emissions from combustion of fuels, electricity generation, or other sources. Emissions must include all GHG SSRs within the system boundary, from the establishment of amended land management practices and associated inputs, through to the end of the Project Commitment Period. This includes embodied emissions of all equipment, amendments, and consumables used in the project. The Project Proponent is responsible for identifying all sources of emissions directly or indirectly related to project activities.

Any emissions from sub-processes or process changes that would not have taken place without the CDR Project must be fully considered in the system boundary. Any activity that ultimately leads to the issuance of Credits should be included in the system boundary.

Where projects are implemented on land under active production prior to the project start date, emissions associated with continuation of pre-project productivity are excluded from the calculation (see Section 9.8).

The system boundary must include all relevant GHG SSRs controlled and related to The Project, including but not limited to the SSRs set out in Table 1. Values for all SSRs outlined in Table 1 must be strictly positive. Any emissions reductions will not count to offset positive emissions for purposes of calculating CO2e_Removals. See 8.2.1.1 for further details.

If any GHG SSRs within Table 1 are deemed not appropriate to include in the system boundary, they may be excluded provided that robust justification and appropriate evidence is provided in the PDD. Furthermore if any SSR is expected to be negligible, they may be excluded in line with Section 5 of the GHG Accounting Module.

Table 1. Scope of activities and GHG SSRs to be included in the system boundary.

Emissions associated with The Project's impact on activities that fall outside of the system boundary of The Project must also be considered. This is covered under Leakage in Section 9.5.4.

Miscellaneous GHG emissions are those that cannot be categorized by the GHG SSR categories provided in Table 1. The Project Proponent is responsible for identifying all sources of emissions directly or indirectly related to project activities and must report any outside of the SSR categories identified as miscellaneous emissions.

In line with the GHG Accounting Module v1.1, the Project must:

• Consider all GHGs associated with SSRs, in alignment with the United States Environmental Protection Agency’s definition of GHGs which includes: carbon dioxide (CO₂), methane (CH₄), nitrous oxide (N₂0) and fluorinated gasses such as hydrofluorocarbons (HFCs), perfluorocarbons (PFCs), sulfur hexafluoride (SF₆) and nitrogen trifluoride (NF₃). For CO₂ stored, only CO₂ shall be included as part of the quantification. For all other activities all GHGs must be considered. For example, the release of CO₂, CH₄, and N₂O is expected during diesel consumption;

• Quantify emissions in tonnes CO₂ equivalent (t CO₂e) using the 100-year Global Warming Potential (GWP) for the GHG of interest, based on the most recent volume of the IPCC Assessment Report (currently the Sixth Assessment Report); and

• Consider materiality of SSRs in line with Isometric requirements.

The Baseline scenario for improved soil management assumes that the activities associated with The Project do not take place and that any infrastructure associated with The Project is not built.

The Counterfactual is the CO₂ stored that would have occurred under business as usual management practices over the Crediting Period in the absence of The Project. This is detailed in Section 9.4.

Improved soil management interventions may involve reductions in activities that result in emissions. A limited set of emissions reductions - specifically reduced CO₂, N₂O, and CH₄ from diesel use in tractors corresponding to fewer passes in no- and reduced-tilling intervention and avoided N₂O emissions from less fertilizer inputs into soils - are scoped in the Agricultural Practices Reduction Module. The Agricultural Practices Reduction Module scopes the eligibility criteria for evaluating these sources, as well as the accounting approach.

In order for a Project to claim emissions reductions credits, The Project must engage in interventions to increase SOC; A Project cannot generate stand-alone emissions reductions credits.

The permissible emissions reductions scoped in the Agricultural Practices Reductions Module are not expected to have any positive emissions associated with them that are not also related to the intervention to generate removals. All emissions with The Project shall be assigned to the term CO₂e_Emissions,RP for purposes of estimating CO2e_{Removals, RP} as outlined in Section 9. Any leakage emissions corresponding to yield reductions associated with the project must be allocated CO2e_{Removals, RP} in Equation 1.

Additionally, any emissions reductions shall be counted separately to removals and cannot be used to offset CO₂e_Emissions,RP for purposes of net CDR Quantification as outlined in Section 9.

If Reductions are generated, they must be submitted together with Removals as part of a GHG Entry for every Reporting Period:

$$GHG Entry = CO₂eRemovals + CO₂eReductions$$

Where:

• CO₂eRemovals are the net removals, quantified in accordance with the Improved Soil Management Protocol. CO₂eRemovals must be greater than zero.
• CO₂eReductions are net reductions, quantified in accordance with this Module. CO₂eReductions may be zero.

See the specific Agricultural Practices Reduction Module for specific details on emissions reductions eligible under this protocol.

The Reporting Period for improved soil management projects represents the interval of time over which removals are calculated and reported for Verification. The minimum duration of a Reporting Period is one year and the maximum duration is five years.

The increase in total net CO₂e removal is calculated for at Reporting Period and is referred to hereafter as CO₂e_Removal,RP. The net CO₂e removal must be conservatively determined, such that there is high confidence that, at a minimum, the credited quantity of CO₂e was removed and stored in the assessed pools.

GHG emission calculations must include all emissions associated with project activities occurring within the Reporting Period. This includes:

• emissions associated with project establishment, allocated to the Reporting Period on a pro-rata basis;

• operations emissions occurring within the Reporting Period, including those arising from changes to tillage, fertilizer application, cover cropping, or other soil management practices;

• any end-of-life or reversal-risk emissions allocated to the Reporting Period; and

• market and activity-shifting leakage emissions occurring outside the system boundary that are attributable to the Reporting Period.

Changes in carbon stocks within eligible pools must be estimated following the requirements within the intervention Module under which the Project is crediting.

In line with the Isometric Standard, this Protocol requires that Removal Credits are issued ex-post. Credits may only be issued once an increase in the relevant carbon pools has been measured and verified within the project boundary, and after accounting for all associated emissions and uncertainty discounts.

Net CO₂e removal for an improved soil management project for each Reporting Period (RP) is calculated as:

$$CO_2e_{Removal,RP} = CO_2e_{Stored,RP} - CO_2e_{Counterfactual,RP} - CO_2e_{Emissions,RP}$$

(Equation 1)

Where:

$CO2e_{Removal,RP}$ is the total net carbon removal for the reporting period in tonnes CO₂e

$CO2e_{Stored,RP}$ is the total change in carbon removed from the atmosphere and stored within the project boundary over the Reporting Period, calculated in accordance with Section 9.3, in tonnes CO₂e

$CO2e_{Counterfactual,RP}$ is the total change in counterfactual carbon that would have been stored within the project area in the absence of project activities over the Reporting Period, calculated in accordance with Section 9.4. This term ensures that only additional carbon storage attributable to the project is credited in tonnes CO₂e

$CO2e_{Emissions,RP}$ is the total GHG emissions associated with project activities over the Reporting Period, including all sources within the system boundary set out in Table 1 and calculated in accordance with Section 9.7, in tonnes CO₂e

The total increase in the amount of CO₂e stored for an improved soil management project over the most recent Reporting Period $RP_n$ is calculated as:

$$CO_2e_{Stored,RP_n} = (CO_2e_{Stored,t=n} - CO_2e_{Stored,t=0}) - \sum_{i=1}^{n-1}CO_2e_{Stored,RP_i}$$

(Equation 2)

Where

$CO_2e_{Stored,RP_n}$ is the total increase carbon storage from project activities over the most recent reporting period ($RP_n$) in tonnes CO₂e

$CO_2e_{Stored,t=n}$ is the total carbon storage within the project area at time t=n, the end of the most recent Reporting Period, in tonnes CO₂e

$CO_2e_{Stored,t=0}$ is the total carbon storage within the project area at time t=0, the time of project initiation, in tonnes CO₂e

$CO_2e_{Stored,RP_i}$ is the total increase carbon storage from project activities calculated for the prior reporting period ($RP_i$) in tonnes CO₂e

For the values from prior Reporting Periods ($CO_2e_{Stored,RP_i}$), these values represent the values calculated at those time points based on the data availability at that time. This does not refer to back-calculated values from the current time point using all currently available data.

At any given time point, the carbon storage within the Project Area is calculated as:

$$CO_2e_{Stored,t} = CO_2e_{SOC,t} + CO_2e_{AGB,t} + CO_2e_{BGB,t}$$

(Equation 3)

Where:

$CO_2e_{Stored,t}$ is the total CO₂e stored across all eligible organic carbon pools at time $t$, in tonnes CO₂e

$CO_2e_{SOC,t}$ is the total carbon stored as soil organic carbon at time $t$, calculated in accordance with the appropriate methods under the intervention Module, in tonnes CO₂e; this term is mandatory for all projects under this Protocol

$CO_2e_{AGB,t}$ is the total carbon stored in aboveground woody biomass at time $t$ in tonnes CO₂e. This term is optional and its inclusion is subject to requirements within the intervention Module the project is crediting under

$CO_2e\_{BGB,t}$ is the total carbon stored in belowground woody biomass at time $t$ in tonnes CO₂e. This term is optional and its inclusion is subject to requirements within the intervention Module the project is crediting under

The mandatory carbon pool under this Protocol is soil organic carbon ($CO_2e_{SOC,t}$), since it represents the primary storage reservoir for all project types within scope. The eligibility of inclusion of aboveground and belowground woody biomass pools is subject to requirements within the intervention Module under which the Project is crediting. All quantification of storage pools must follow the methodological and reporting requirements within the intervention Module under which the Project is crediting.

Deadwood, litter, and non-woody herbaceous biomass carbon pools are excluded from the calculation of $CO_2e_{Stored,RP}$ under this Protocol as these pools are considered transient.

The value of $CO_2e_{Counterfactual}$ represents the storage of carbon that would have happened in absence of the project interventions and act as a reference from which to assess the additionality of the project interventions. The Project Proponent is responsible for generating a conservative estimate of $CO_2e_{Counterfactual}$ following the requirements within the Module under which the Project is crediting.

$CO_2e_{Counterfactual,RP_n}$ is assessed as the change in cumulative carbon storage within the counterfactual scenario over most recent reporting period ($RP_n$):

$$CO_2e_{Counterfactual,RP_n} = (CO_2e_{Counterfactual,t=n} - CO_2e_{Counterfactual,t=0}) - \sum_{i=1}^{n-1}CO_2e_{Counterfactual,RP_i}$$

(Equation 4)

Where:

$CO_2e_{Counterfactual,RP_n}$ is the total increase carbon storage in the counterfactual scenario over the most recent reporting period ($RP_n$) in tonnes CO₂e

$CO_2e_{Counterfactual,t=n}$ is the total carbon storage within the counterfactual scenario at time t=n, the end of the most recent Reporting Period, in tonnes CO₂e

$CO_2e_{Counterfactual,t=0}$ is the total carbon storage within the counterfactual scenario at time t=0, the time of project initiation, in tonnes CO₂e

$CO_2e_{Counterfactual,RP_i}$ is the total increase carbon storage in the counterfactual scenario calculated for the prior reporting period ($RP_i$) in tonnes CO₂e

The values from prior Reporting Periods ($CO_2e_{Counterfactual,RP_i}$) represent the values calculated at those time points based on the data availability at that time. This does not refer to back-calculated values from the current time point using all currently available data.

The methods and requirements for calculating $CO_2e_{Counterfactual,t}$ are specified within the intervention Module under which the Project is crediting.

The total GHG emissions associated with a Reporting Period, RP can be calculated as:

$$CO_2e_{Emissions,RP}=CO_2e_{Establishment,RP}+CO_2e_{Operations,RP }+CO_2e_{EndOfLife,RP}+CO_2e_{Leakage,RP}$$

(Equation 5)

Where:

• $CO_2e_{Emissions,RP}$ represents the total GHG emissions for a Reporting Period, in tonnes of CO₂e.

• $CO_2e_{Establishment,RP}$ represents the GHG emissions associated with project establishment, represented for the RP, in tonnes of CO₂e, see Section 9.5.1.

• $CO_2e_{Operations,RP}$ represents the total GHG emissions associated with operational processes for a RP, in tonnes of CO2e, see Section 9.5.2.

• $CO_2e_{EndOfLife,RP}$ represents GHG emissions that occur after the RP and are allocated to a RP, in tonnes of CO2e, see Section 9.5.3.

• $CO_2e_{Leakage,RP}$ represents GHG emissions associated with the impact of the Project on activities that fall outside of the system boundary of the Project, over a given RP, in tonnes of CO₂e, see Section 9.5.4.

The following sections set out specific quantification requirements for each term in Equation 5.

GHG emissions associated with project establishment should include all historic emissions incurred as a result of project establishment, including but not limited to the SSRs set out in Table 1, such as biomass removal, irrigation installation, etc.

Project establishment emissions occur from the point of project inception to the moment before the first removal activity takes place. GHG emissions associated with project establishment may be amortized over the anticipated project lifetime, or per output of product. Requirements for amortization are outlined in Section 7 of the GHG Accounting Module.

GHG emissions associated with CO₂e_{Operations,RP} should include all emissions associated with operational activities, including but not limited to the SSRs set out in Table 1.

For improved soil management projects, the Reporting Period covers a set period of time (e.g., one year), during which soil organic carbon accumulates. CO₂e_{Operations,RP} emissions must be attributed to the Reporting Period in which they occur. This includes any emissions associated with management of the soil system or harvesting/processing of commodities for which production was established by the Project. The emissions from these activities must be calculated as explained in Section 9.7. Allocation outside of the current Reporting Period may be permitted in certain instances, on a case by case basis in agreement with Isometric.

CO₂e_EndOfLife,RP includes all emissions associated with activities that are anticipated to occur after the Crediting Period until the end of the Project Commitment Period. This includes activities related to ongoing monitoring for Reversals.

CO₂e_EndOfLife,RP must be estimated upfront and allocated in the same way as set out for calculation of CO₂e_{Establishment,RP}.

Given the uncertain nature of CO₂e_EndOfLife,RP emissions, assumptions must be revisited at each Reporting Period and any necessary adjustments made. Furthermore, if there are unexpected CO₂e_EndOfLife,RP emissions that occur after the Project has ended, then the Reversal process described in the Reversals and Buffer Pools Section of the Isometric Standard will be triggered to compensate for any emissions not accounted for.

CO₂e_Leakage,RP includes emissions associated with a Project's impact on activities that fall outside of the system boundary of The Project. It includes increases in GHG emissions as a result of the Project displacing emissions or causing a secondary effect that increases emissions elsewhere.

For Projects engaging in interventions to increase SOC the primary risk of leakage comes from reduced agricultural productivity on the project sites leading to supply shortfalls and price-induced market leakage emissions. This could present through reduced agricultural yields or reduced livestock productivity corresponding to the intervention. Market leakage could also result from retention of agricultural residues for SOC improvements that historically went to market for alternative productive use.

Specifics of leakage considerations and calculation approaches can be found in appropriate Modules under this Protocol.

GHG emissions accounting must be undertaken in alignment with the GHG Accounting Module v1.1, which ensures a consistently rigorous standard in how GHG emissions are quantified and reported between different CDR Projects and approaches. This includes:

• Requirements for data quality, including a detailed data quality hierarchy for activity data and emission factors;

• Consideration of materiality in emissions accounting;

• Emissions amortization requirements;

• Co-product and by-product allocation requirements. For improved soil management projects, this will apply to the production of co-products such as co-products from a cover- or rotational-crop for which the oil or grain is harvested for productive use;

• Waste input accounting relating to inputs to the process that are wastes, for example manure as a fertilizer amendment if it is demonstrated to be in excess.

The Energy Use Accounting Module 1.3 provides requirements on how energy-related emissions must be calculated for the Project so that they can be subtracted in the net CO₂e removal calculation. It sets out the calculation approach to be followed for intensive facilities and non-intensive facilities and acceptable emission factors.

Energy emissions are those related to electricity or fuel usage. They may include, but are not limited to:

• Emissions associated with operating mobile farm equipment (e.g., diesel use in tractors)

• Emissions associated with operating stationary farm equipment (e.g., electricity for pumps)

The GHG Accounting Module v1.1 provides requirements on how transportation and energy-related emissions must be calculated for the Project so that they can be subtracted in the net CO₂e removal calculation.

Embodied emissions are those related to the life cycle impact of equipment and consumables. They may include, but are not limited to:

• Embodied emissions associated with any new equipment required for executing the project intervention(s)

• Embodied emissions associated new seeds or seedlings that are applied as part of the project

• Embodied emissions associated with any soil additives (e.g., biostimulants, fertilizer)

Transportation emissions are those related to transportation of products and equipment. They may include, but are not limited to:

• Emissions associated with the transportation of any new seeds or seedlings

• Emissions associated with the collection, processing, and transport of any new products resulting from the intervention (e.g., from a new rotational crop)

• Emissions associated with the transportation of any additional agricultural inputs (e.g., fertilizer, pesticides, herbicides)

The storage reservoirs of the CO₂ removed through soil management interventions are soil organic carbon and optionally live aboveground woody biomass and belowground woody biomass depending on the intervention Module. The durability of a CDR process refers to the length of time for which CO₂ is removed from the Earth’s atmosphere and cannot contribute to further climate change.

For requirements associated with durability, reversal risk, risk assessment and management and buffer pool, please refer to the intervention Module under which the Project is crediting.

The durability of awarded Credits are defined by the Module under which the Project is crediting.

The durability must not exceed any of the following:

• Project Commitment Period. Project Proponents must be accountable for maintaining carbon stocks, monitoring for reversals, and compensating for any reversals throughout the Project Commitment Period.
  • This Project Proponent–level obligation persists regardless of the contract length of any individual enrolled landowner. Where individual contracts are shorter than the Project Commitment Period, the Project Proponent must demonstrate how monitoring and reversal liability will be maintained across the full Project Commitment Period, including through the Ongoing Monitoring Period set out in Section 5.1 where applicable.
• Project financial plan. Project Proponents must demonstrate continued payments and/or financial incentive to maintain carbon stocks during The Project.
• Soil carbon maintenance activities. Project Proponents must continue soil carbon management and risk mitigation practices to maintain carbon stocks throughout the Project Commitment Period.

Reversal risks which may threaten the durability of project system carbon and project-level risk assessment and mitigation requirements are discussed in Section 10.2 and Section 10.3, respectively.

A soil carbon-wide Buffer Pool managed by Isometric is used to insure Credits against Reversals. Throughout any Ongoing Monitoring Period, project carbon stocks must be monitored Reversals to ensure Credits achieve their stated durability. Upon detection and quantification of carbon losses, Credits issued to the Buffer Pool will be canceled in equal proportion to the loss (see Section 10.4 and Section 10.5).

Project Proponents must design The Project in a manner that is aligned with long-term durability and sustainability. Well-designed projects should mitigate risk of changes in land use and land management or Reversal after The Project ends (see Section 5.0). Support for long-term durability may consist of evidence of the following, and ideally a combination of factors:

• Ongoing project financial sustainability after the Project Commitment Period, such as through alternative income streams from commodity production within the project system system or process improvements which encourage continued maintenance;
• Establishing a plan to attain legal protection beyond the Project Commitment Period; and
• Building technical capacity or employment to facilitate long-term carbon stock management.

Reversals are defined as reductions in stored carbon within applicable pools that may result in emissions of CO₂ to the atmosphere. Reversal risk is quantified by assessing the likelihood of a disturbance event occurring over a period of time and estimating the severity of the disturbance in terms of carbon loss. Disturbance events may be natural or anthropogenic, such as fire, drought/heat, insect and disease, changes in management practices, and land use conversion. A disturbance event which results in a reduction in soil carbon and/or other covered pools is considered a loss event. The duration of disturbance events may be over multiple years (e.g., drought) or for a very limited duration (e.g., flood).

The likelihood and severity of disturbances are influenced by external and project-related factors.

External factors:

• Climate change effects
• Changes in areas adjacent to the project area(s) (e.g., land ownership, land use, farming practices, industrial activities, upstream water stress, ecosystem change)
• Suitability of landscape for supporting project activities
• Regulatory changes
• Historic disturbances in and around the project area(s)
• Changes in economics and/or market incentives

Project-related factors:

• Project plan (e.g., climate resilient interventions, management practices)
• Project governance (e.g., operations and financial structure, community ownership, local training)
• Risk mitigation safeguards
• Changes in land use, management, or ownership of the project area(s)
• Participation of enrolled landowners

Furthermore, the risk profile of The Project may change over the Project Commitment Period due to:

• Temporal variation in the risk profile of the project system due to age or characteristics
• Temporal variation in the risk profile of natural risks (e.g., wildfires, drought) and anthropogenic risks (e.g., land use changes)
• Length of the Project Commitment Period

Projects must complete the Risk Assessment(s) of the Improved Soil Management intervention Module(s) the Project is crediting against, the results of which are independently evaluated by a third-party VVB.

The Risk Assessment is used to determine the risk profile of the Project, including risks to Credit delivery and storage. Aspects of the Project which have higher risk exposure should be accompanied by an appropriate risk mitigation plan. To safeguard against high risk projects, the Project must score below the indicated thresholds to be eligible for crediting under this Protocol.

The Risk Assessment(s) must be updated each Reporting Period by the Project Proponent and increased risk scores will result in additional mitigation activities.

The following safeguards are required for all improved soil management projects and must be in place at the start of the Project and maintained throughout the Project Commitment Period. The Project Proponent must:

• Site the project appropriately to reduce disturbance risk from neighboring activities.
• Reduce risk of unintended fires through a fire management plan (e.g., removing fuel, fire breaks or fire towers, fire-fighting equipment and training).
• Reduce risk of drought through a water management plan (e.g., securing water supply, water infrastructure, drought resilience measures). If the Project has been identified to present other risks to local water resources, additional measures must be included that describe how the Project will mitigate risks and safeguard water resources.
• Reduce risks of flooding and erosion through land and water management practices.
• Identify and reduce risks unique to the Project, e.g., regionally pervasive pests.

As outlined in the Buffer Pools Section of the Isometric Standard, the Buffer Pool is a mechanism used to insure against risks of Reversals that may be observable and attributable to the Project through monitoring.

Currently, there is insufficient published scientific evidence to quantitatively account for climate change, management activities, or project age and translate this into a highly accurate Buffer Pool contribution. As a result, we apply either a flat contribution requirement on the Project or a model to translate the Risk Assessment for the intervention Module into a Buffer Pool contribution. As actuarial data improve and more research is published, Protocol requirements will be updated accordingly.

To be eligible under this Protocol, the Project must either:

• Contribute 20% of Credits generated in a Reporting Period to the Buffer Pool; or
• Opt-in to the method outlined in the intervention Module(s) the Project is crediting against. This project-specific method permits changes to the contribution for each Reporting Period as the risk profiles of the Project Proponent and project system change over time. The Buffer Pool contribution determined from this approach cannot be less than 10% of the Credits generated in any Reporting Period.
• In addition to the contribution determined under either of the approaches above, an additional 5% of Credits generated in the Reporting Period must be contributed to the Buffer Pool for any Reporting Period in which contractual agreements with enrolled landowners or operators are not in place for the full duration of the Project Commitment Period across all portions of the Project Area. This additional contribution reflects the increased Reversal risk associated with management practices after contract expiry, and applies on top of, not in lieu of, the base contribution.

The Buffer Pool contribution will be held in an improved soil management-wide Buffer Pool managed by Isometric. Pooling of a diversified portfolio of improved soil management projects across geographic regions, project types, spatial scales and temporal scales can reduce the exposure to systemic risks stemming from nature-based projects constrained to a geographic area or ecological type^12,13,14. The improved soil management-wide Buffer Pool composition will be transparently reported on the Isometric Registry.

The Buffer Pool Compensation Process is governed by the Isometric Standard. The following procedures apply upon detection and quantification of a loss event.

• Within the Crediting Period. For Reversals that occur during the Crediting Period (e.g., widespread disturbance), loss of soil carbon is incorporated into the quantification at each Verification. If the net CO₂e storage term (Equation 2) in a Reporting Period is found to be negative (soil carbon stock at t < soil carbon stock at t-1), Buffer Pool Credits are canceled equal to the net emissions from the Reporting Period.
• Within any Ongoing Monitoring Period after the end of the Crediting Period. Reversals that occur after the Crediting Period must be quantified following the requirements within the intervention Module that the Project is crediting under and fully compensated by the Buffer Pool within one year of the loss event.
• Procedure for Avoidable Reversals. Isometric cancels Credits in the Buffer Pool equal to the Reversal.
  • During the Crediting Period: Project Proponents must replenish the canceled Credits in the Buffer Pool using Credits generated in the next Reporting Period before additional Credits are issued.
  • Within any Ongoing Monitoring Period after the end of the Crediting Period: Project Proponents must replenish the canceled Credits in the Buffer Pool using Credits generated from other projects under operation by the Project Proponent, or using Credit generated from another project, deemed of equivalent quality by Isometric, at the Project Proponent's expense.
• Procedure for Unavoidable Reversals. Isometric cancels Credits in the Buffer Pool equal to the Reversal.
• Buffer Pool Depletion. If the Reversal has depleted the project's share of the Buffer Pool, the Project will be in a deficit, and must make up the loss within the next Reporting Period, or within one year of the loss event if the loss occurs during an Ongoing Monitoring Period. If the Project Proponent does not replenish the canceled Credits in the Buffer Pool in the amount equal to the Reversal, then the Project fails and is ineligible for future crediting. All Credits are canceled.

For more details on Reversals, refer to Isometric Standard sections covering risk of reversal and buffer pools.

Monitoring, reporting, and quantification of reversals must follow the requirements set within the Improved Soil Management intervention Module(s) The Project is crediting under.

Isometric would like to thank the following external contributors to this Protocol:

• Nuala Fitton PhD

• Benjamin Dube PhD

Buffer Pool Contribution

• Isometric will review and adapt third-party tools and datasets, such as buffer pool density maps, as they become publicly available to enable project- and site-specific determination. Buffer Pools will be reassessed and scaled as appropriate to account for risk amplification or mitigation due to management activities and climate change.

Geospatial Dynamic Baselines

• The current baseline approach is designed to incorporate dynamic variables which evolve over the course of The Project. As techniques improve for remote sensing of soil carbon relevant variables, Isometric will consider opportunities to incorporate dynamic baseline approaches which utilize remotely sensed data between project areas and control areas in the broader region to assess additionality.

Fractionation of Soil Carbon Pools

• It is known that different fractions of soil carbon (i.e., particulate organic matter vs mineral-associated organic matter) have different durabilities. However, measurement cost and complexity makes it challenging to implement characterization in the context of the voluntary carbon market. Advances in measurement and opportunities for implementation in the context of carbon projects will be monitored and considered for implementation in future versions.

Insurance

• Insurance providers can provide a third party risk assessment, are financially incentivized to correctly price risk, and have a fiduciary responsibility to pay out in the event of a Reversal. Presently, insurance cannot be used for the purpose of reducing Buffer Pool allocation size. This is due to limitations in the transparency in risk calculations, lack of data to substantiate risk models, and lack of supply of high quality Carbon Credits. As this area develops, insurance will be considered for inclusion in future versions of the Protocol. At minimum, insurance solutions must provide coverage for the entirety of the Project Commitment Period, either through a policy which extends for the full Project Commitment Period (e.g., 100 year policy) or an insurance contract extending for the full Project Commitment Period (e.g., 1 year policy with contract for 100 years).

Quantification Methods

• The Protocol currently uses quantification via ex situ sampling and model-based as the primary approaches. As technological advances continue via other approaches (e.g., in situ measurements, remote sensing, digital soil mapping) additional options may be explicitly incorporated into the Protocol.

Stakeholder Engagement

• More detailed guidance on stakeholder identification and differentiation will be considered for future versions of the Protocol.

• Additional guidance on due diligence required to demonstrate that stakeholder rights are upheld will be considered for future versions of the Protocol.

• Further requirements on requirements for projects with non-smallholder designs may be considered for future version of the Protocol.

Uncertainty

• Project Proponents are expected to quantify and justify the uncertainty associated with each parameter in the carbon removal calculation.

• Additional guidance on model validation metrics will be considered for future improvements.

• Isometric will consider providing a case study of uncertainty propagation for carbon stock quantification.

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2. Lessmann, M., Ros, G. H., Young, M. D., & De Vries, W. (2022). Global variation in soil carbon sequestration potential through improved cropland management. Global Change Biology, 28(3), 1162-1177. ↩

3. Jones, P., Hannam, J., & Collins, C. (2026). Evaluating the economic co-benefits of soil carbon sequestration: The test case of the UK. Land Use Policy, 161, 107839. ↩

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7. Di Sacco, A., Hardwick, K. A., Blakesley, D., Brancalion, P. H., Breman, E., Cecilio Rebola, L., ... & Antonelli, A. (2021). Ten golden rules for reforestation to optimize carbon sequestration, biodiversity recovery and livelihood benefits. *Global Change Biology*, *27*(7), 1328-1348. ↩

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9. Gann, G. D., McDonald, T., Walder, B., Aronson, J., Nelson, C. R., Jonson, J., ... & Dixon, K. W. (2019). International principles and standards for the practice of ecological restoration. *Restoration Ecology. 27 (S1): S1-S46.*, *27*(S1), S1-S46. ↩

10. Di Sacco, A., Hardwick, K. A., Blakesley, D., Brancalion, P. H., Breman, E., Cecilio Rebola, L., ... & Antonelli, A. (2021). Ten golden rules for reforestation to optimize carbon sequestration, biodiversity recovery and livelihood benefits. *Global Change Biology*, *27*(7), 1328-1348. ↩

11. United Nations General Assembly. (2007). United Nations declaration on the rights of indigenous peoples (A/RES/61/295). Retrieved from [https://www.un.org/development/desa/indigenouspeoples/wp-content/uploads/sites/19/2018/11/UNDRIP\\\_E\\\_web.pdf\](https://www.un.org/development/desa/indigenouspeoples/wp-content/uploads/sites/19/2018/11/UNDRIP\_E\_web.pdf) ↩

12. United Nations General Assembly. (2007). United Nations declaration on the rights of indigenous peoples (A/RES/61/295). Retrieved from [https://www.un.org/development/desa/indigenouspeoples/wp-content/uploads/sites/19/2018/11/UNDRIP\\\_E\\\_web.pdf\](https://www.un.org/development/desa/indigenouspeoples/wp-content/uploads/sites/19/2018/11/UNDRIP\_E\_web.pdf) ↩ ↩²

13. United Nations. (2016). Free, prior, and informed consent: An indigenous peoples’ right and a good practice for local communities. Retrieved from [https://www.un.org/development/desa/indigenouspeoples/publications/2016/10/free-prior-and-informed-consent-an-indigenous-peoples-right-and-a-good-practice-for-local-communities-fao/\](https://www.un.org/development/desa/indigenouspeoples/publications/2016/10/free-prior-and-informed-consent-an-indigenous-peoples-right-and-a-good-practice-for-local-communities-fao/) ↩ ↩²

14. Cohn, A. S., Newton, P., Gil, J. D., Kuhl, L., Samberg, L., Ricciardi, V., Manly, J.R., & Northrop, S. (2017). Smallholder agriculture and climate change. Annual Review of Environment and Resources, 42(1), 347-375. ↩ ↩²