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Biochar’s Emerging Role in New Zealand’s Greenhouse Gas Inventory
Biochar is rapidly emerging as a viable soil-based carbon removal pathway and is attracting increasing interest from countries seeking to expand and strengthen their National Greenhouse Gas Inventories (NGHGIs). In response to the IPCC 2019 Refinement—which provides updated, scientifically robust guidance to improve national GHG inventories—the Ministry for Primary Industries (MPI) commissioned Environmental Accounting Services (EAS), in partnership with Manaaki Whenua – Landcare Research, to develop a national-scale methodology and supporting database. This work will enable the inclusion of biochar soil amendments within Aotearoa New Zealand’s National Greenhouse Gas Inventory.
The Challenge
MPI faced a strategic and technical gap: without a robust national methodology and data system, they could not:
- Recognise soil carbon removals from biochar in national inventory reporting.
- Provide a consistent basis for future farm-level incentives linked to national accounting.
- Respond effectively to international developments, including the IPCC 2019 Refinement and emerging voluntary carbon market methodologies.
At the same time, the New Zealand biochar sector was still developing, with several complicating factors:
- A small number of large producers contrasted with many small “artisan” operations.
- Limited data on the quality, quantity, and end-use of biochar produced and applied to soils.
- Constrained laboratory capacity for specialised biochar analyses.
- No national database, QA/QC framework, or agreed time-series start date for inventory reporting.
Project Goals
MPI sought to establish a scientifically robust, future-proof foundation for biochar accounting. The project’s objectives were to:
- Develop a feasible Tier 2 inventory method for biochar applied to mineral soils, aligned with NZ’s existing soil carbon methods and IPCC 2019 Refinement guidance.
- Design a national database capable of capturing key variables from biochar producers (e.g., mass applied, feedstock, organic carbon fraction), supported by clear SOPs and QA/QC processes.
- Characterise the current biochar landscape, including production volumes, end uses, testing practices, and laboratory capability.
- Incorporate te ao Māori perspectives and assess opportunities and barriers relating to Māori agribusiness and biochar use.
Why MPI Selected EAS
EAS brought a uniquely strong combination of:
- Over 17 years of cross-sector MRV (Measurement, Reporting, Verification) expertise, including leadership in national Agriculture, Forestry, and Other Land Use (AFOLU) methodology development.
- Experience in voluntary carbon market methodologies, enabling MPI to explore how farm-scale biochar amendments could be incentivised beyond mandatory reporting.
- Extensive, direct involvement in shaping global standards, including:
- Dr Carly Green serving as a Lead Author of the 2019 IPCC Refinement, specifically Volume 4, Chapters 2 and 3.
- Authoring national guidance in the Methods and Guidance Documentation (MGD) component of the Global Forest Observations Initiative (GFOI).
- EAS’s work on wetlands guidance for Australia.
- Policy work for wetlands in New Zealand.
This multidisciplinary MRV and market expertise positioned EAS to deliver both a technically robust Tier 2 method and forward-looking design options for farm-level incentives.
Our Approach & Contribution
EAS—working closely with Manaaki Whenua – Landcare Research—delivered a comprehensive package of technical and strategic outputs:
1. National Tier 2 Inventory Method
A peer-reviewed, IPCC-consistent methodology for quantifying changes in mineral soil carbon stocks from biochar amendments. This method harmonises with New Zealand’s existing soil carbon approaches while enabling transparent, accurate, and consistent reporting.
2. Database Architecture and QA/QC System
A practical, scalable database design supported by:
- Standard Operating Procedures (SOPs)
- QA/QC processes
- Clear definitions of required producer-supplied variables
This system creates a long-term pathway for consistent activity data collection across the biochar sector.
3. Sector Assessment and Engagement
A detailed assessment of:
- Biochar production volumes
- End uses (soil vs non-soil applications)
- Testing and laboratory capability
- Te ao Māori considerations, including opportunities for Māori agribusiness
4. Voluntary Carbon Market Options
An extension report outlining how farm-scale biochar amendments could be incentivised through voluntary carbon markets, including readiness conditions and strategic alignment with international methodologies.
Outcomes
The project provided MPI with a fully developed Tier 2 method and an operational-ready database design, enabling the future inclusion of biochar amendments in the NGHGI in a manner that is:
- Transparent
- Accurate
- Consistent
- Compatible with existing national reporting frameworks
At the close of the project, MPI and the Ministry for the Environment were progressing implementation through:
- Cross-agency collaboration to address final report recommendations
- Consideration of publishing national standards for reporting biochar properties, ensuring compatibility with voluntary market requirements
- Operationalisation of the database design, enabling activity data collection
- Continued engagement with the Biochar Network to support sector development and alignment
Photo by Dylan de Jonge on Unsplash
