Problem with results in contribution analysis

Question

When I view my results, only one process contributes to the Climate Change category. I have copied the results from excel below. I don't know why other processes, such as N fertiliser, are coming up null?

Contribution GWP Process Amount Unit

100.00% Basil - RER 0.16851 kg

100.00% Plastic granulate secondary (low metal contamination), production mix, at plant, from post-consumer plastic waste, via grinding, metal separation, washing, pelletization, plastic waste with low metal fraction - EU-28 0.16851 kg

0.00% market for nitrogen fertiliser, as N | nitrogen fertiliser, as N | APOS,U - GLO 0 kg

0.00% market for compost | compost | APOS, U - GLO 0 kg

0.00% market for potassium fertiliser, as K2O | potassium fertiliser, as K2O | APOS, U - GLO 0 kg

0.00% market for pump, 40W | pump, 40W | APOS, U - GLO 0 kg

0.00% ammonium nitrate phosphate production | phosphate fertiliser, as P2O5 | APOS, U - RER 0 kg

0.00% electronic component machinery production, unspecified | electronic component machinery, unspecified | APOS, U - GLO 0 kg

0.00% market for grass seed, Swiss integrated production, at farm | grass seed, Swiss integrated production, at farm | APOS, U - GLO 0 kg

0.00% light emitting diode production | light emitting diode | APOS, U - GLO 0 kg

0.00% market for nitrogen fertiliser, as N | nitrogen fertiliser, as N | APOS, S - GLO 0 kg

0.00% market for paper, newsprint | paper, newsprint | APOS, U - RER 0 kg

0.00% polyethylene production, low density, granulate | polyethylene, low density, granulate | APOS, U - RER 0 kg

Comments

Just a couple of thoughts. Hard to say exactly what might be going on without more detail.

Did you choose any allocation methods? Do you et the same result if you choose "None". If Causal is chosen, the allocation values for the various inputs to Basil - RER could be set to 0.

Otherwise, I would make sure that you have the correct impact assessment method as well. If you go to the inventory tab in the results, are the CO2 flows for all the processes 0 as well?

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Thanks for your reply. I am using the Ecoinvent 3.6 database and trying to calculate the emissions for basil production. When I calculate the results, the contribution tree only accounts for the system processes such as plastics and the unit processes (that includes fertilisers and steel for infrastructure) come up null.

I changed the allocation methods to "none" as you said but I am still seeing the same problem. I'm now wondering if it has something to do with the "Provider" in the inputs and outputs section of the Process? As I look at the "Provider" section now, each processes has a purple P and white background, as a unit process, but when I calculate the results, plastics and electricity are coming up as system processes.

Thanks for your help so far.