Methodology History

The methodology is applicable to Agricultural Land Management (ALM) project activities that involve a change in rice cultivation practices. The methodology was developed by Terra Global Capital LLC with support from Applied Geosolutions LLC, the Environmental Defense Fund and the California Rice Commission.
Parent Methodology

The methodology is modular in structure, lending itself to applicability in rice-growing regions around the world. The parent methodology provides definitions, applicability criteria, project boundary definition, baseline and additionality requirements, quantification methods, monitoring and verification requirements, and uncertainty calculations for all modules. The methodology defines Rice-Growing Regions, geographic regions in which the climate and rice management practices are relatively homogeneous, and over which the DNDC model (the main quantification tool in this methodology) is calibrated and validated.

California Regional Calibration Module

Approved simultaneously with the parent methodology is a regional calibration module for California. Eligible activities in California include (1) removal of rice straw from the field after harvest, (2) replacing water seeding with dry seeding, and (3) early drainage at the end of the growing season. Project Proponents who implement practices that increase Nitrogen use efficiency concurrently with these practices can combine this methodology with an ACR methodology for nitrous oxide emissions from fertilizer management in order to receive credits from reducing nitrous oxide emissions in addition to methane and/or carbon dioxide.

Mid-South Regional Calibration Module

The regional calibration module for the Mid-South applies to two U.S. rice-growing regions: 1) the Mississippi River Delta in Arkansas, Mississippi and Missouri, and 2) the Gulf Coast area in Louisiana. The Gulf Coast area in Texas may be added at a later date.

Eligible activities under the Mid-South module include: 1) removal of rice straw from the field after harvest, 2) early drainage at the end of the growing season, 3) intermittent flooding during the growing season, and 4) increased water and/or energy use efficiency, achieved through measures including but not limited to: convert contour levees to precision or zero grade; use of side inlet/poly piping systems; use of more efficient diesel pumps; switch from diesel to electric pumps; use of soil moisture sensors to tailor flood to water needs. Project Proponents who implement practices that increase Nitrogen use efficiency concurrently with these practices can combine this methodology with an ACR methodology for nitrous oxide emissions from fertilizer management in order to receive credits from reducing nitrous oxide emissions in addition to methane and/or carbon dioxide.

Structural Uncertainty Deduction Factors

Projects must apply an uncertainty deduction factor to account for model structural uncertainty and ensure conservative crediting. The structural uncertainty represents the uncertainty inherent in the DNDC model and is set using independent validation data (directly measured daily methane fluxes on benchmark sites) available at the time of methodology publication. Additional data will become available in the future, allowing the structural uncertainty deduction factors to be updated. In addition, as more fields are registered, structural uncertainty should decline, so the structural uncertainty deduction depends on the number of fields in all projects registered on ACR. Project proponents must always use the most recent version of structural uncertainty deduction factors.

DNDC Model

Baseline and project emissions are quantified using the Denitrification – Decomposition (DNDC) model. Please download the version of DNDC included below, which has been specifically calibrated for rice projects. Other versions (e.g. from the UNH website) are not to be used.

Methodology History

The methodology details requirements for greenhouse gas emission reduction accounting from wetland restoration activities implemented on degraded wetlands of the Mississippi Delta. The methodology quantifies increased carbon sequestration in aboveground biomass, belowground biomass, and soil organic carbon over and above the baseline scenario. Increases in CO₂, methane or nitrous oxide, if significant and attributable to the project activity, must be quantified and deducted from net emission reductions.

This methodology has been revised from its original publication in order to provide equations to quantify the greenhouse gas emissions resulting from the degradation and erosion of the wetland soil horizon, specifically the top 50 cm.

The modular format provides flexibility for numerous types of wetland restoration projects including those that require hydrologic management, as well as allowing Project Proponents to select whether wetland loss will be included in the baseline. By including hydrologic management as a restoration technique the methodology addresses the broader issues of diffuse pollution and nutrient management by sustainably managing nutrient-rich waters as a resource for wetland restoration.

The methodology was developed by Dr. Sarah K. Mack of Tierra Resources LLC, with contributions from Dr. Robert R. Lane and Dr. John W. Day, and with funding from Entergy Corporation. The methodology may in the future be expanded to wetland restoration in other regions, and other wetland restoration practices.

Structure and previously approved versions

The Wetland Restoration Methodology Framework module, WR-MF-WL_v2-0, provides the generic functionality of the methodology, indicates which other modules are mandatory and optional, and contains the final calculation of Emission Reduction Tonnes (ERTs). WR-MF constitutes, together with the modules and tools it calls upon, a complete wetland restoration baseline and monitoring methodology.  An Errata and Clarification document has also been published and required for use with the current version of the methodology.

Included underneath WR-MF are:

Methodology History

The methodology details requirements for quantifying greenhouse gas (GHG) emission reductions by reducing the amount of nitrogen used to fertilize crops. The methodology was jointly developed by Michigan State University (MSU) and the Electric Power Research Institute (EPRI).

The methodology is applicable to the Agriculture, Forestry and Other Land Use (AFOLU) sector, and is specific to Agricultural Land Management (ALM) project activities. The scope of this methodology is limited to on-farm reductions in N fertilizer rate associated with the management of N-containing synthetic and organic fertilizers that reduce net N₂O emissions from annual or perennial cropping systems. Emissions reductions and crediting for project activities occur by reducing the N fertilizer rate during the crediting period, when compared to the baseline (pre-project) period.

During a project crediting period, adherence to Best Management Practices (BMPs) as they relate to the application of synthetic and organic N fertilizer at the cropping site is required. These BMPs are related to N fertilizer formulation (or N content of organic additions) and dates and methods of application. Project Proponents shall describe and justify in the GHG Project Plan how relevant BMPs have been adhered to.

Three project categories are eligible under this version of the methodology:

1. Category 1: Proposed projects located in the U.S. North Central Region (Illinois, Indiana, Iowa, Kansas, Michigan, Minnesota, Missouri, Nebraska, North Dakota, Ohio, South Dakota and Wisconsin) that involve corn in row-crop systems such as continuous corn and rotations of corn-soybean or corn-soybean-wheat. Projects in this category use Method 1, an IPCC Tier 2-equivalent relationship between N₂O emissions and N application rates developed by MSU, to calculate N₂O emissions reductions. Only the corn component of a rotation is eligible for crediting. Projects located within the NCR boundary that involve crops other than corn, including crops in rotation with corn, are eligible under Categories 2 and 3.
2. Category 2: Proposed projects located worldwide that include fertilized agricultural crops may submit empirical data published (or accepted to be published) in peer-reviewed scientific journals documenting that the use of the Tier 1 emission factor (EF₁ = 1.0% [0.01]; IPCC 2006) is conservative for calculating N₂O emissions at the project site(s). ACR will engage experts to review the data.
3. Category 3: Proposed projects located worldwide that include fertilized agricultural crops may use a new project-specific emission factor if project proponents demonstrate using empirical data published (or accepted to be published) in peer-reviewed scientific journals that the use of a new Tier 2 emissions factor is conservative for calculating N₂O emissions at the project site(s). ACR will engage experts to review the data.

During a project crediting period, projects initially accepted for inclusion in Category 2 can be re-assigned to Category 3, should new data become available. A retroactive crediting mechanism is provided to incentivize the collection of N₂O emissions data and the development of emissions factors compatible with IPCC Tier 2 methodologies.

Methodology History

The methodology applies to the introduction of high-efficient thermal energy generation units utilizing non-renewable biomass, or retrofitting of existing units (e.g. complete replacement of existing biomass fired cook stoves or ovens or dryers with more-efficient appliances), to reduce use of non-renewable biomass for combustion. It falls in the CDM category Energy Efficiency: displacement or energy efficiency enhancement of existing heat generation units resulting in saving of non-renewable biomass and reduction of GHG emissions.

ACR has approved two modifications to the existing CDM methodology:

1. AMS II.G uses fossil fuel emission factors to calculate emission reductions, based on an assumed shift from non-renewable biomass to fossil fuels by households in the project area. Households are in many countries using fuelwood/charcoal in the baseline, and when they install an efficient cookstove they still use fuelwood/charcoal but less of it, leading to a reduction in use of and emissions from non-renewable biomass. To recognize this, ACR proposes replacing the fossil fuel emission factors in Equation (1) with appropriate and conservative biomass emission factors for fuelwood and charcoal, derived from the 2006 IPCC Guidelines for National Greenhouse Gas Inventories.
2. When fuelwood is harvested, the below-ground root biomass is not removed, and a portion of the above-ground biomass is also not removed. The second modification introduces a new paragraph 15, with an adjustment to the parameters B_old (quantity of biomass used in the absence of the project activity) and B_new (quantity of biomass used in the project activity) to account for carbon stocks in fuelwood not harvested.

Both modifications were reviewed and approved by ACR’s independent Agriculture, Forestry and Other Land Use (AFOLU) Technical Committee and open for public comment by stakeholders.

Methodology History

The methodology accounts for the carbon sequestration and avoided greenhouse gas (GHG) emissions related to compost additions to grazed grasslands. The methodology was developed by Terra Global Capital with support from the Environmental Defense Fund, Silver Lab at the University of California Berkeley, and the Marin Carbon Project.

Adding compost to grazed grasslands has been demonstrated to be an effective way to increase soil carbon sequestration and avoid emissions related to the anaerobic decomposition of organic waste material in landfills. Grazed grasslands represent a large portion of agricultural working lands, and a number of recent studies have highlighted that globally grasslands are in a state of degradation.

The methodology provides a quantification framework for emissions reductions from a number of activities including avoiding anaerobic decomposition of organic material used in compost production, directly increasing soil organic carbon (SOC) content by applying compost to grazed fields, and indirectly increasing SOC sequestration through enhanced plant growth in amended fields. Apart from the economic benefit of increased forage production, applying compost to grazed grasslands also has many environmental co-benefits such as improved soil quality, decreased risk of water and wind erosion by increasing soil aggregation, and increased nutrient and water availability for vegetation.

Methodology History

The methodology details requirements for quantification of GHG emissions reductions in the agriculture sector resulting from changes in how fertilizer is applied and used. It incorporates site specific data into a peer-reviewed, tested and highly parameterized model, the Denitrification-Decomposition (DNDC) model, to quantify direct N₂O emissions as well as indirect emissions from leaching and ammonia volatilization.

This methodology is applicable to Agricultural Land Management (ALM) ACR project activities that involve a change in fertilizer management including changes in fertilizer rate, type, placement, timing, use of timed-release fertilizers, use of nitrification inhibitors, and other factors.

ACR has closed the public comment period and initiated scientific peer review for v2.1 of its Methodology for N2O Emission Reductions through Changes in Fertilizer Management. Upon final approval and publication this version will replace v2.0. The methodology’s purpose, scope, applicability conditions, eligible practices, and quantification approach remain unchanged overall. ACR has made updates and clarifications to improve the flexibility of the methodology by providing eligibility criteria for other greenhouse gas quantification models in addition to DNDC. Upon final approval and publication this version will replace v2.0.

The conclusion of the peer reviewers is that the methodology should not be accepted at this time. They stated that the scientific literature does not provide sufficient evidence of the stability of soil carbon sequestration in fields treated with biochar using H:C_org ratio correlations as cited in the International Biochar Initiative’s Standard Test Method for Estimating Biochar Carbon Stability (BC₊₁₀₀).

ACR welcomes the opportunity to revisit approval of the methodology at such time as there is clearer scientific consensus behind the approach proposed for methods to measure, monitor and verify biochar carbon stability.

Methodology History

Biochar is produced through the pyrolysis of biomass. The methodology quantifies and credits both the avoided emissions from combustion or decomposition of biomass in the baseline and enhanced carbon sequestration at sites where biochar is applied. In the baseline scenario, biochar feedstocks would be combusted or decompose, releasing carbon dioxide and/or methane. In the project scenario, pyrolysis physically and chemically transforms the feedstocks into a more recalcitrant form that can be applied to soil for long-term sequestration. Under this methodology, biochar may be produced from any biomass residues from forestry and agriculture, municipal solid wastes, and other biomass-based materials approved for use under the International Biochar Initiative’s IBI Biochar Standards (2013) provided such feedstocks also meet sustainability criteria specified in the methodology.

The conclusion of the peer reviewers is that the methodology should not be accepted at this time.  They felt the scientific literature did not provide sufficient evidence of the stability of soil carbon sequestration in fields treated with biochar using H:C_org ratio correlations as cited in the International Biochar Initiative’s Standard Test Method for Estimating Biochar Carbon Stability (BC₊₁₀₀).

ACR welcomes the opportunity to revisit approval of the methodology at such time as there is clearer scientific consensus behind the approach proposed for methods to measure, monitor and verify biochar carbon stability.