Can LCA results from, e.g. Climate Change or Acidification, can be summed up?

Question

Hello,

I have LCA results from a supplier but no primary data. Can I do a own LCA for our processes and sum up the results, e.g. in terms of kg CO2eq or kg CFC-11 eq from my suppliers LCA and my own LCA?
And are there differences between the single impact assessment methods that need to be considered when doing this?

Kind regards,

Rob

Answer 1

Hello Rob,

this has been discussed often in the history of LCA; basically, it is possible mathematically once the impact category results are normalised, but whether it should allowed to do so is debated. ISO 14040 follows the idea that this weighting requires (too much) subjectivity and thus must be kept out of an ISO compliant study that compares products; some methods like ReCiPe or EF permit this aggregation, with the logic to make the result more accessible.

Best wishes,

Andreas

Comments

Hello Andreas,

thank you for your answer. I am not sure if I have formulated my question correctly. It is about the fact that I have received from a supplier
the results of an LCA for 1 t of product.
I would like to use these results (kg CO2e1, kg SO2e1, ...) and add the environmental impacts of our production process to these values (kg CO2e2, kg SO2e2, ...)
 ==>
kg CO2eSupplier + kg CO2e Own Process = kg CO2e final;
kg SO2eSupplier + kg SO2e Own Process = kg SO2e final, ...
Can this be done without further ado or should at least the underlying methods (impact assessment methods) be identical?