How is the data present in each process of the database used to calculated the environmental effects?

Question

I am trying to understand how the values for the environmental impacts are calculated by the software, from the data in the database? For example, for the singular process "Continuous filament glass fibre (assembled rovings), at plant" how is the GWP of this process calculated just from the outputs?

Many thanks for your help.

Answer 1

openLCA calcualtes the results in two steps

1) Life Cycle Inventory (LCI) - Calculation type Quick results (included in Calculation type Analysis)

Listing and quantification of all flows that cross the system boundary of the product system which you built from a specific process. The inventory results are based on the underlying database of your study. You can find the inventory results, upon calculating results, in the inventory results tab which includes three setions namely Inputs, Outputs and Total requirements.

2) Life Cycle Impact Assessment (LCIA) - Calculation type analysis (includes your inventory)

The Life Cycle Impact Assessment translates all flows from the inventory results (inputs and outputs) into impact categories which present the environmental impacts of your product system in a way that is much easier to understand and to interpret than the simple list of flows. This transaltion is done by a Life Cycle Impact Assessment (LCIA) method. You can open LCIA methods via the openLCA navigation window Indicators and parameters -> Impact assessment methods. For instance, if you open the LCIA method CML (baseline) you can open the tab impact factors and you will see which elementary flows are captures by the respective impact category (e.g. Climate change - GWP100) of the LCIA method that you are using.

I hope this helps.