3. Principles of dynamic LCA

3.1 "CO2 has no smell" and the importance of time

From a "terrestrial ecosystem balance" point of view, we understand that the GHGs emitted by plant matter are part of a (natural) cycle of decomposition (GHG emissions) and growth (GHG removals). This cycle takes place over a period of a few years for agro-sourced plants and several decades for tree wood. Conventional LCA methods, which follow ISO1 4040 and ISO 14044 standards, advocate that the "global warming" impact linked to biogenic CO ₂ be neglected, following the assumption that any biogenic GHG release from a product is compensated for by the growth of the plant that replaces the material used for that product. Compared with emissions from materials of fossil origin, which took...