Methodology and data sources

This page explains how numbers are produced in LCALens. It is written to align with the GHG Protocol Corporate Standard and Scope 2 Guidance and with ISO 14064-1. LCALens is not certified by, and does not claim endorsement from, either body.

Where factors come from

Factors enter the library in only three ways:

• Parsed from an official file whose address, version, licence and SHA-256 checksum we record.
• Derived in our Factor Lab from verified factors with a stored equation that anyone can re-run for the same result.
• Uploaded by a customer as their own factor, kept private to their organisation and labelled as user provided.

We never type factor values or global warming potentials from memory, and AI tools cannot mark anything as verified.

Review

Every imported factor starts as pending review. A reviewer checks its value, unit, boundary, greenhouse gas basis, year and geography against the source before approving it. Derived factors need a second person: the author of a derivation cannot verify it, and the database re-runs the equation during review.

Calculation

Emissions equal activity data multiplied by the applicable factor. Arithmetic uses exact decimal numbers in the database. Each saved result stores the inputs, the factor versions, the methodology version and the code version. Locked results cannot be edited or deleted.

Factors carry a boundary such as direct combustion, well-to-tank or cradle-to-gate. Methods accept only the boundaries they are designed for, so upstream fuel emissions cannot be counted as Scope 1 by mistake. Biogenic CO₂ is reported separately from Scope 1, 2 and 3 totals.

Global warming potentials

We store 100-year GWP values from the IPCC Fourth, Fifth and Sixth Assessment Reports. Our current import is from the GHG Protocol's compilation of IPCC values (August 2024), which cites the IPCC primary sources. Where a source publishes factors already converted to CO₂e, we record the GWP basis it used.