Why non-financial assurance belongs on the audit committee's agenda, not the sustainability committee's

Sustainability committees exist to govern strategy and ambition. Audit committees exist to govern the independence and credibility of reporting. Those are different jobs, and a sustainability committee reviewing the assurance on its own sustainability report has a structural conflict of interest built in from the start. Where a separate sustainability committee exists, the workable model keeps assurance oversight with the audit committee and gives the sustainability committee visibility into findings as they affect programme decisions, not ownership of the assurance question itself.

A working oversight cycle mirrors the reporting calendar: plan and provider-independence approval before the year starts, progress checks while verification work is underway, scrutiny of scope and preliminary findings once report assurance begins, formal receipt of the assurance report treated with the same weight as a financial audit report, and a rolling findings register, standing independence confirmation, and a documented escalation path sitting on every meeting's agenda regardless of quarter.

None of this requires audit committee members to become sustainability experts. It requires enough literacy in GHG accounting, the relevant reporting frameworks, and what independence actually means in this context to ask three questions credibly: is this independent, is this credible, is this the right provider for this domain. A committee that can't ask those questions can't actually oversee the answer.