How do you measure biogenic emissions?
Biogenic CO₂, released when organic materials are burned or decomposed, is reported separately from your Scope 1, 2 and 3 totals, not included in them.
If your organisation burns wood, biogas, or other organic materials as fuel, the CO₂ released looks like a direct emission from your own operations. In many ways it is, but under the GHG Protocol, it's treated differently from fossil fuel combustion and sits outside your scope totals.
What are biogenic emissions?
Biogenic CO₂ is carbon dioxide released from the combustion or decomposition of biological material - organic matter derived from living or recently living organisms.
As a plant grows, it absorbs CO₂ from the atmosphere through photosynthesis, storing that carbon in its leaves, stems, and trunk. When that plant is later burned as fuel or left to decompose, the stored carbon is released back into the atmosphere as CO₂ - the same carbon that was there to begin with. No new carbon has been added to the atmosphere - it has simply completed a cycle (the 'Carbon Cycle').
This is fundamentally different from burning fossil fuels, where carbon that has been locked underground for millions of years is released as a net addition to the atmosphere. Because biogenic CO₂ recirculates recently sequestered carbon, the GHG Protocol requires it to be reported separately from your Scope 1, 2 and 3 totals rather than included in them.
However, this is a somewhat simplified treatment. Companies with significant biogenic emissions - particularly those involving land use, carbon stocks, or biogenic products - should review the GHG Protocol's Land Sector and Removals Standard for more detailed guidance.
Common sources of biogenic emissions
| Source | Example |
|---|---|
| Wood and biomass boilers | Burning wood pellets, wood chips or timber offcuts for heat |
| Bagasse combustion | Burning sugarcane fibre residue for energy at sugar mills |
| Biogas combustion | Burning gas from anaerobic digestion of food waste or wastewater |
| Biofuel combustion | Burning ethanol or biodiesel in vehicles or generators |
| Biomass co-firing | Burning a mix of coal and wood in the same boiler |
| Biodegradation | CO₂ from composting or organic waste decomposition |
What is and isn't outside of scopes
⚠️ Important
Only the CO₂ from biogenic combustion or decomposition is reported outside of scopes. CH₄ and N₂O from the same activity are genuine additions to atmospheric greenhouse gases and must be included in Scope 1 in the normal way.
| Emission | Treatment |
|---|---|
| CO₂ from burning wood, biogas, bagasse, biofuel | Outside of scopes - disclosed separately & optionally |
| CH₄ from burning biomass or biofuels | Included in Scope 1 |
| N₂O from burning biomass or biofuels | Included in Scope 1 |
| CO₂ from burning fossil fuels (gas, diesel, coal) | Included in Scope 1 |
How Trace handles biogenic emissions
Trace excludes biogenic CO₂ from your Scope 1 total in line with GHG Protocol requirements. Where biogenic fuels are entered, the CO₂ component should be calculated and tracked separately, if required. CH₄ and N₂O from those same sources contribute to your Scope 1 total as normal.
We are currently working on implementing a tool with one of our Partners in order to be able to account for biogenic emissions. If your business needs to measure biogenic emissions, please reach out to our team to see how we might assist.
Additional Notes
Co-fired equipment: If a boiler burns a mix of fossil fuel and biomass, the CO₂ emissions must be split, the fossil portion goes into Scope 1, the biogenic portion is reported outside of scopes. The split should be proportional to the energy content of each fuel.
Biogas from landfill or digesters: The CO₂ from combusting captured biogas is biogenic and sits outside of scopes. However, any unburned or fugitive methane from the same system is a Scope 1 emission (or Scope 3 if it occurs in your value chain).
Land use change: The simplified treatment above applies to direct combustion and decomposition. If your organisation's activities involve changes in land use, such as clearing forests for operations, the carbon stock implications are more complex. Refer to the GHG Protocol's Land Sector and Removals Standard for guidance.
AASB S2 considerations
AASB S2 follows IFRS S2, which requires GHG Protocol methodology for emissions measurement. Biogenic CO₂ disclosures outside the scopes are not a mandatory line item under AASB S2, but disclosing them is considered best practice for completeness and transparency, particularly for organisations in sectors where bioenergy use is material, such as agriculture, food processing, or waste management.