{% hint style="info" %}
As a reminder, emissions from each emission source of the organisation are estimated as follows:
Emission from a source = [Activity data](/methode-bilan-carbone-r-en/4-accounting/4.2-method-for-collecting-activity-data.md) x [emission factor](/methode-bilan-carbone-r-en/4-accounting/4.3-method-for-selecting-emission-factors.md) = [result](/methode-bilan-carbone-r-en/4-accounting/4.5-emission-profile.md) ± [higher](/methode-bilan-carbone-r-en/4-accounting/4.4-method-for-estimating-uncertainties.md)
{% endhint %}
Estimates and measurements inherently involve a margin of error; the vast majority of scientific methods therefore associate values called uncertainties with the results of measurements or estimates.
These uncertainties allow the derivation of a 95% confidence interval, i.e. an interval \[Value 1; Value 2] within which the true value of what is being measured or estimated has a 95% probability of lying.
The Bilan Carbone® method allows [to determine uncertainties](/methode-bilan-carbone-r-en/4-accounting/4.4-method-for-estimating-uncertainties/4.4.2-how-should-they-be-determined.md) in a qualitative and quantitative manner.
Taking into account the uncertainties related to activity data and emission factors and calculating their resulting effect on the estimated quantities of GHGs aims to help organisations identify priorities for improving the quality of these data, and thus to implement Process improvement actions [Process improvement action](/methode-bilan-carbone-r-en/5-transition-plan/5.2-construction-of-the-action-plan.md#les-differentes-categories-dactions) and carbon accounting thereafter. The values of the uncertainties must also be taken into account when analysing results and developing the transition plan. The ultimate objective is to optimise the reliability of future inventories and to steer decision-making appropriately.
Quantitative uncertainties can be propagated across the different categories of the assessment or across the entire assessment to produce a 95% confidence interval. It should be noted that the uncertainty propagated across the entire assessment is of limited relevance because it does not provide useful information for decision-making. A more detailed analysis of uncertainties, category by category and emission source by emission source, is far more relevant for the continuous improvement of the approach.
***
*Do you have a comprehension question?* [*Consult the FAQ*](/methode-bilan-carbone-r-en/appendices/faq.md)*. The method is living and therefore likely to evolve (clarifications, additions): find the* [*track of changes here*](/methode-bilan-carbone-r-en/foreword/history-and-tracking-of-changes.md)*.*
---
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