IMPACT World+ / a globally regionalized method for life cycle impact assessment

IMPACT World+ is a life cycle impact assessment method which characterizes thousands of substances spanning across various compartments and sub-compartments of the environment. It differentiates 19 impact categories at midpoint level and 36 impact categories at damage level. For more information on IW+, refer to our website and scientific article. For information on the updates of IMPACT World+, you can register to the newsletter of CIRAIG.

The v2.2.1 update corresponds to an adjustment of the previously released v2.2, notably on the climate change indicators. The v2.2 radically changed the contributions to the ecosystem quality damage indicators as well as introduces new resources indicators based on the dissipation of resources and not the extraction.

IMPACT World+ comes in three interpretation levels: midpoint, expert and footprint. You can find explanations for these three interpretation levels here.

The expert and midpoint versions of IMPACT World+ also come with two different implementations regarding how to account for biogenic carbon. One with the traditional biogenic carbon neutrality approach (e.g., where biogenic carbon dioxide is set at 0 and biogenic methane is set at 27kgCO2eq for GWP100) and one including the uptake of biogenic carbon dioxide, where the release of biogenic carbon is therefore set at the same CFs as fossil carbon, but the uptake is with a negative sign, i.e., a -1/+1 approach for biogenic carbon (look for the files marked “(incl. CO2 uptake)”).

While we provide the –/+1 approach, we must make it clear to the users that this approach is heavily dependent on the quality of the inventory you are using, and that there are still issues currently with the LCI databases (even in ecoinvent 3.12). Furthermore, if you are using this approach, you either MUST adopt a cradle-to-grave approach to both account for the uptake and release of biogenic carbon (otherwise you will only account for the uptake of the carbon and have skewed results) or if you adopt a cradle-to-gate approach because you need to provide results to someone downstream of your supply chain you MUST communicate with that downstream user to tell them that they should account for the release of biogenic carbon in a -1/+1 approach also, otherwise, you and your downstream user will double count the benefits of using biogenic products, which is incorrect. This is especially true is the case of food products where the carbon emissions post cons