How does EsgaSIS actually calculate a figure?

Activity quantity × resolved emission factor = kg CO2e, and then the factor used is snapshotted onto the entry. The snapshot is the part that matters: a published figure stays reproducible even after the registry is updated, because the entry records the value, tier and resolution that produced it rather than pointing at whatever the registry says today.

The sequence for a single entry:

Convert the quantity to the factor’s unit — litres to litres, kWh to kWh — refusing rather than guessing if the units cannot be reconciled.
Resolve a factor for the activity, country, region and year, preferring an exact regional match and falling back through nearest-earlier vintage, then country, then global default.
Record how good that match was, and warn where the factor is older or newer than the reporting year.
Multiply, and write the result together with a snapshot of the factor value, its tier and the resolution path.

For grid electricity, waste and water the fallback chain stops early and deliberately. These model a process that differs by country, so if no factor exists for your country the software declines to produce a number and records an exclusion with the reason. It does not borrow a neighbour’s factor.

A stored figure is never rewritten when the registry changes. Figures do not silently move underneath a report you have already sent to a customer, and a historic snapshot is left as it was — it records what was believed at the time, and rewriting it would defeat the point of keeping one.

How does EsgaSIS actually calculate a figure?

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