For many years now I’ve noticed this strange section of the W&B display called “Consumption and CO2 Emission” that has no other inputs or info. I always assumed it was either a future feature or a leftover text that shouldn’t be there. But as the years have gone on it’s stayed put.
So wanted to reach out and see what the experts say on this.
Tried searching for this but surprisingly the only thing I could find was a closed thread from Aug 2020 that never received an answer 
CO2 and Emissions on Fuel Page - Archives / Bugs & Issues - Microsoft Flight Simulator Forums