In completing an LCA project (for a wood product) in openLCA, I ran impact assessment methods for two versions of TRACI – one associated with Ecoinvent v3.3 and one associated with openLCA LCIA methods 1.5.6. The results were drastically different, with the TRACI LCIA 1.5.6 results for GWP being almost 4 times greater than using Ecoinvent v3.3 TRACI. After digging into the impact assessment methods impact factors, I saw that Ecoinvent TRACI only included 4 flows for carbon dioxide, with no biogenic flows. The LCIA TRACI includes 30 flows for carbon dioxide, including biogenic carbon.
I also saw similar differences in results/impact factors between the two CML (baseline) versions (Ecoinvent v3.3 and LCIA 1.5.6).
I ended up using openLCA LCIA v1.5.6 since its flows were more comprehensive, however I would still like to know why the flows are different between LCIA v1.5.6 and ecoinvent 3.3 if the impact assessment method is the same (TRACI). Has anyone else noticed this?