# We want to say we cut emissions by 20 percent. What do we need to back it?

Canonical: https://senseible.earth/answers/cut-emissions-by-percent-claim-evidence

A base year and a current year calculated the same way, with the same boundary and factors, and a statement of whether the cut is absolute or per unit of output. If you sold a unit or changed method, recalculate the base year first. Keep the workings so anyone can repeat the 20 percent.

## Checklist

- Base year figure and current year figure, same scopes.
- Same emission factors, or both years recalculated with new ones.
- Absolute or intensity named, with the unit.
- Main reasons for the change listed.

## Common errors

- Comparing a year with Scope 3 to a year without.
- A cut that comes only from lower production, reported as efficiency.
- Netting carbon credits off the inventory.

## What Senseible does here

Senseible keeps each figure behind a claim traceable to the invoices and bills it came from, so a reader can check the number rather than take the wording on trust.

- [Recalculate the base year](https://senseible.earth/answers/recalculate-base-year-after-selling-a-unit)
- [Absolute or intensity target](https://senseible.earth/answers/absolute-or-intensity-reduction-target)
- [CCPA greenwashing guidelines](https://senseible.earth/answers/ccpa-greenwashing-guidelines-india)

Sources: [GHG Protocol Corporate Standard](https://ghgprotocol.org/corporate-standard), [ISO 14021, Environmental labels and declarations: self-declared claims (iso.org)](https://www.iso.org)

Last reviewed 2026-10-23.