Contribution Tree - Sum of the contributers not equal to the final amout - how?

Question

I just did an analyse-calculation for the ecoinvent dataset "chipboard production, white lined | folding boxboard/chipboard | Cutoff, U".

When I click on the contribution tree, I see that the value for chipboard production is 0.89 kg CO2eq.

However, when I create the sum of all the CO2eq amounts from the contributer, I get the result: 0,53 kg CO2eq.

How is this possible?

Answer 1

Hi

I am also facing the same problem. Even though some contributions are shown in negative values some factors have no value. The total is not equal to 100%. For transportation, the only question mark" is shown". If you got the solution, can you please guide me as well?

Comments

In my experience this usually means something is incorrectly connected in your product system. Another test you can do is a Monte Carlo analysis to see if you get a ? for all results. One of the usual culprits is using Allocation method "None" when the outputs of a single process are both connected to something. Good luck.