Auditing urban nature access claims for sustainable city governance

Abstract Urban governments use nature-access indicators to assess biodiversity, health, equity and regenerative-planning goals, yet policy conclusions can depend on how the claim is constructed. We audit six specifications—inventory, access geometry, distance model, threshold, population allocation and vulnerability definition—using three purposive core cities, transfer checks, a 30-city data-readiness screen and an entrance-aware London validation. Plausible alternatives changed access levels by up to 48.82 percentage points, reversed some environmental-justice classifications and substantially altered underserved target populations. A matched London diagnostic showed that network penalties narrowed from 36.95 points at 300 m to 0.52 points at 1000 m. We therefore propose a decision-stability envelope that reports a preferred specification alongside ranges, equity-direction changes, target-set reclassification and missing operational data. The cases are not globally representative; they demonstrate an auditable workflow for testing whether urban nature claims are sufficiently stable to guide regenerative and equitable planning.