In life cycle accounting, biogenic carbon (carbon stored in plants and wood) must be carefully tracked. However, a common problem arises when a process is split by economic value rather than mass. For example a sawmill is allocated 90% to high-value timber and 10% to low-value sawdust based on price, the timber might "inherit" 90% of the forest's carbon uptake, even if it only represents 50% of the physical wood.
To prevent this distortion, ecoinvent includes a specific flow called "Carbon dioxide, biogenic, resource flow correction." (more information in ecoinvent's LCIA implementation report, section 6.4.1). This flow acts as a "balancing entry" to ensure the carbon math adds up to the actual physical reality of the product.
How Earthster handles biogenic corrections
In Earthster, we map the ecoinvent "resource flow correction" directly to the Climate change, biogenic (EN15804+A2/Midpoint) impact result exchange. We do this to maintain a clear distinction between physical reality and methodological adjustments.
Correction vs. physical emission: Environmental exchanges represent the physical movement between human activity and the natural environment, such as 1 kg of CO2 physically exiting a chimney. These are the "building blocks" of an LCA. The correction does not represent a physical gas entering or leaving a system; it is a mathematical adjustment to ensure the "carbon books" balance after allocation. That's why we do not model it as a standard environmental exchange.
Methodological accuracy: By mapping it directly to the EN15804+A2 biogenic climate category, we ensure the adjustment is applied exactly where it’s needed. This maintains the strict
-1/+1carbon balance required by international standards (such as EN15804+A2), ensuring that your final biogenic carbon score accurately reflects the physical carbon content of your product.
Checking your inventory results for resource corrections
In Earthster
In your cycle's inventory resource corrections appear as
Climate changeandClimate change (biogenic)with a context ofEN15804+A2/Midpoint
In ecoinvent
Resource corrections can be checked in ecoquery in the section for LCI results of a given dataset.
