Impact assessment results doubt

Question

Hi everyone,

I am using Ecoinvent combined with Agrybalise and REcipe midpoint (H) to evaluate the environmental impacts of 2 product systems.

In these 2 product systems there are some common processes, for example "diesel consumption", but with different value.

The point is, when I run the calculation, let's take as an example the GWP100 indicator, for the process that has more inputs and higher value, this indicator is lower.

Just to explain better, in both product systems I have " diesel consumption" as a common process. "System A" has higher input value for diesel than "System B" (and in general there are more inputs in System A), but System B shows the higher impact, referring of course to the same target amount. Also considering the process contribution, same process shows higher value impact for system B than A

How is this possible? What am I missing? I have checked all the values and processes but I cannot figure out why this is happening. I mean, for me doesn't make a lot of sense but maybe for some reason this can be correct? Thank you.

Answer 1

Hi, which version of openLCA are you using? Which version of Agrbalyse and from where? To your question, the impact of a process in a calculation result depends on how much of the process is used, and on the impact of the process; if you have a process with half of the impact of another but it is used 10 times more in another system compared to the other process, you will have higher impacts for it (if I understand your question)

Comments

in the inventory results, total requirements section: the amount column shows how much product of each process (each line) is used in the calculated system