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.

Methodology History

The methodology is applicable to project activities that introduce N₂O abatement measures in nitric acid plants. Nitric Acid is used to produce products such as fertilizer and various plastics and is produced from the oxidation of ammonia via catalysis. The methodology applies to those projects using either Secondary N₂O abatement or Tertiary N₂O abatement. Secondary N₂O abatement refers to the catalytic removal of N₂O from the intermediate gas stream between the ammonia reactor and the absorption tower. Tertiary N₂O abatement refers to the destruction of N₂O in the tail gas from the absorption tower.

Methodology History

The methodology details requirements for oil & gas companies to reduce fugitive emissions of methane, a potent greenhouse gas, by retrofitting existing high-bleed pneumatic controllers in the U.S. with low-bleed options. According to the U.S. Environmental Protection Agency, high-bleed pneumatic controllers are among the largest sources of vented methane by equipment type in the domestic oil & natural gas industry.

Methodology History

When project proponents wish to propose modifications to an existing methodology, ACR requires an approval process either via ACR’s regular public consultation and scientific peer review process in the case of significant modifications, or by an independent ACR AFOLU Technical Committee in cases where the proposed modifications are minor.

First methodology modification, approved April 2011:

• Adds to the list of eligible technologies/measures a switch from conventional fuels (e.g. fuelwood and charcoal) to renewable fuels. As in AMS I.E Version 03 with “renewable energy technologies,” renewable fuels reduce the use of conventional fuels and the project proponent must demonstrate what portion of those fuels are non-renewable woody biomass.
• Provides a new equation to derive B_y, the quantity of woody biomass substituted or displaced. This is based on the quantity of renewable fuels sold, with terms to account for the fact that less than 100% of renewable fuel sold may displace traditional biomass, and for the difference in net calorific value (NCV) between the new and old fuels.

• Requires monitoring of fuel use by households, in a similar annual sampling approach as is required in AMS I.E Version 03 for monitoring the use of renewable energy technologies.

Second methodology modification, approved July 2013:

The second modification results from an analogous modification to CDM methodology AMS II.G, Energy Efficiency Measures in Thermal Applications of Non-Renewable Biomass, approved by the ACR AFOLU Technical Committee and published in July 2013. In that modification, the fossil fuel emission factors used in AMS II.G to calculate baseline emissions are based on an assumed shift from non-renewable biomass to fossil fuels. These were replaced by biomass emission factors for fuelwood and charcoal.

The rationale was that households in many developing countries where this methodology may be applied are using fuelwood/charcoal in the baseline, and when they install an efficient cookstove they still use fuelwood/charcoal but less of it, rather than switching to fossil fuels. This leads to a reduction in use of and emissions from non-renewable biomass. To recognize this, ACR replaced the fossil fuel emission factors in Equation (1) of AMS II.G with appropriate and conservative biomass emission factors for fuelwood and charcoal, derived from the 2006 IPCC Guidelines for National Greenhouse Gas Inventories.

AMS I.E uses the same fossil fuel emission factors. With the same rationale, ACR in this modification to AMS I.E replaces those with biomass emission factors.