#1 How to account for offset impact flows?

[Troy Hawkins]

In my unit process associated with crop growth I would like to account for the CO2 uptake. It seems reasonable to include an input of "Carbon dioxide, in air" -- "resource" -- "in air". However, now it is unclear how OpenLCA will treat this input in calculation of LCIA impacts. Should I add this flow in my impact method as a positive or negative flow? Should it be entered as an input or output in my process?