Why carbon verification has to be planned before the reporting year ends, not after

The GHG Protocol tells an organisation how to calculate its emissions. It says nothing about whether that calculation is correct, which is precisely what independent verification is for. Disclosure without it isn't assurance, it's self-declaration, and that's the exact distinction regulators and capital markets have stopped accepting at face value over the last few years.

The sequencing mistake is common and avoidable: treating verification as a year-end exercise means evidence has often been discarded by the time anyone asks for it, methodology decisions are hard to reconstruct months later, and the whole engagement gets compressed into a window too short to do properly. A verifier needs to understand the inventory boundary and the data systems as the inventory is being built, the same way a financial auditor does interim work across the year rather than showing up once it's already closed.

Materiality in this context is a tool for focusing effort, not an excuse to skip the hard parts. Scope 3 can't be waved off just because the data is harder to collect. For most organisations it's the majority of the actual footprint, so an inventory that's rigorously verified everywhere except Scope 3 has verified the smaller half of the problem and left the larger half resting on trust.