akar.earthIPCC 2006 Guidelines and 2019 Refinement for AFOLU
IPCC AFOLU guidelines explained: 2006 Volume 4 methods, the 2019 Refinement, Tier 1 to 3 and the Wetlands Supplement for Indonesian peat and mangroves.
The IPCC AFOLU guidelines are the agriculture, forestry and other land use methods in Volume 4 of the 2006 IPCC Guidelines for National Greenhouse Gas Inventories, updated by the 2019 Refinement. They set the carbon pools, equations, tiers and default values that national inventories and most carbon methodologies use, and for Indonesia they are complemented by the 2013 Wetlands Supplement for peat and mangroves.
What the guidelines are
The IPCC Task Force on National Greenhouse Gas Inventories produces methods for countries reporting under the UNFCCC. Key documents for land:
| Document | What it adds |
|---|---|
| 2006 IPCC Guidelines, Volume 4 (AFOLU) | Core methods for forest land, cropland, grassland, wetlands, settlements, livestock and soils |
| 2013 Wetlands Supplement | Drained and rewetted organic soils (peat), coastal wetlands (mangroves, tidal marshes, seagrass) |
| 2019 Refinement | Updates and new default values, including biomass and soil carbon data |
The 2019 Refinement does not replace the 2006 Guidelines. It updates and supplements them, and countries decide how to use it.
Core concepts
- Land-use categories. Forest land, cropland, grassland, wetlands, settlements and other land, with conversions between them.
- Carbon pools. Above-ground biomass, below-ground biomass, dead wood, litter and soil organic carbon. See carbon pools.
- Gain-loss and stock-difference methods. Two ways to estimate carbon stock change: track growth and losses, or compare stocks at two points in time.
- Tiers. Tier 1 uses IPCC defaults, Tier 2 uses country-specific data, Tier 3 uses detailed models or repeated inventories.
- Default values. Tables for growth rates, root-to-shoot ratios, the carbon fraction of dry matter, and emission factors. Default carbon fraction values for wood are close to half of dry biomass; check the table for your forest type.
Who uses it
- National governments for inventories, NDC tracking and REDD+ reference levels.
- Methodology developers who reference IPCC equations and defaults.
- Project developers for parameters where methodologies allow defaults.
- Companies following GHG Protocol land sector guidance.
How it applies in Indonesia and Southeast Asia
IPCC methods shape Indonesian forest carbon accounting in several ways:
- National reporting. Indonesia’s national inventory and forest reference emission levels are built on IPCC methods, with national forest inventory data supporting higher-tier estimates.
- Peat. Indonesia’s peatlands make the Wetlands Supplement central. Emission factors for drained tropical peat under different land uses, and for peat fires, drive large numbers. See peatland REDD+ and peat restoration rules.
- Mangroves. Coastal wetland methods cover biomass and soil carbon in mangroves. Indonesia’s large mangrove area makes these methods significant for blue carbon. See mangrove soil carbon.
- Allometry. IPCC methods allow biomass expansion factors, but project methodologies usually prefer allometric equations, such as the Chave et al. (2014) pantropical model with wood density. See allometric equations.
Domestic rules under Perpres 110/2025 and Permenhut 6/2026 rely on measurement and reporting consistent with national accounting, so aligning project methods with IPCC-based national data reduces friction when units are recorded in SRUK.
Choosing between tiers in a project
Projects often mix tiers by parameter:
| Parameter | Common choice in Indonesian projects |
|---|---|
| Above-ground biomass | Tier 3-style field inventory with allometric equations |
| Root-to-shoot ratio | IPCC default from tables for the forest type, or published local ratios |
| Carbon fraction | IPCC default, unless methodology specifies a value |
| Peat emission factors | Wetlands Supplement defaults, or national data where accepted |
| Soil carbon in mangroves | Field cores, since defaults vary widely |
Document why each choice is conservative.
When a project uses a different value from the national inventory for the same parameter, explain why. Differences between project and national accounting become visible when projects are nested in jurisdictional systems or recorded domestically, and regulators may ask about them.
Common pitfalls
- Using Tier 1 defaults where local data exist. Defaults are broad and can be non-conservative for specific sites.
- Mixing 2006 and 2019 values inconsistently. Pick one source per parameter and document it.
- Ignoring the Wetlands Supplement. Peat and mangrove projects that use only Volume 4 miss key emissions.
- Treating IPCC as a crediting rule. IPCC methods are for inventories; crediting rules on additionality and baselines come from programs.
Relationship to ICVCM CCP status
ICVCM’s robust quantification principle expects methodologies to use conservative, scientifically sound methods. IPCC guidance is the common scientific base. CCP status still depends on the program and methodology. See CCP label.
Next steps
Return to the standards hub, see the DMRV hub, or try our tree CO2 calculator to see how biomass converts to CO2.
Frequently asked questions
What are the IPCC AFOLU guidelines?
They are the agriculture, forestry and other land use methods in Volume 4 of the 2006 IPCC Guidelines for National Greenhouse Gas Inventories, updated by the 2019 Refinement. Countries use them for national inventories, and carbon methodologies use their methods and default values.
What are Tier 1, Tier 2 and Tier 3?
Tiers describe methodological complexity. Tier 1 uses IPCC default values, Tier 2 uses country-specific factors, and Tier 3 uses detailed models or inventories. Higher tiers usually reduce uncertainty.
Which IPCC guidance covers peat and mangroves?
The 2013 Supplement to the 2006 IPCC Guidelines: Wetlands covers drained and rewetted organic soils and coastal wetlands such as mangroves. It is important for Indonesian peat and blue carbon.
Can a carbon project use IPCC default values?
Many methodologies allow IPCC defaults for some parameters, such as root-to-shoot ratios, but often require conservative choices or local data for key parameters. Check your methodology.