The uncertainty of your Carbon Footprint is very important for refining and improving the methodology of your next Carbon Footprints.
In a previous article, we discussed the reliability measurement of your data. In this article, we will focus on calculating the total uncertainty of your Carbon Footprint.
First of all, you can see that a value 'data uncertainty (%)' is associated with each line of your collection Template. This calculation is carried out based on the reliability measurement of the entered value (a measurement that you must estimate) and the uncertainty arising from the emission factor (uncertainty provided by Ademe
Example: A mobility survey was conducted within the company with a high participation rate (the reliability is 85%, so the uncertainty of the value is 15%). Home-to-work car trips are estimated with the emission factor 'Car - Diesel Engine - 2018 0.212kgCO2e/km' with an uncertainty rate of 60%.
The uncertainty calculation Ux is therefore as follows:
In order to calculate the total uncertainty, the following calculation is used. (with Ux: U1,U2...Un)
Example of calculating the total uncertainty:
The calculation performed is as follows: