The Two Clocks of Carbon-Market Governance: National Approval Synchronisation and International Registry Visibility in the CDM-to-PACM Transition

Abstract International carbon-crediting mechanisms combine project-initiated applications with nationally signed acts and centrally published registers. The resulting event dates need not coincide. We construct a project-level audit of the transition from the Clean Development Mechanism (CDM) to the Paris Agreement Crediting Mechanism (PACM), comparing a frozen 8 October 2026 UNFCCC export with a separately acquired 9 November export. Among 285 approved Project Activities (PAs) from 20 host countries with at least five approved activities, the mean country-specific share concentrated on the most common approval date is 89.4%, compared with 38.0% for the original transition-request dates of those same projects (difference 51.3 percentage points; country-cluster bootstrap 95% interval 38.2–63.5). In exploratory, week-constrained permutations preserving country-week composition and the global within-week date distribution, no allocation among 1,800 simulations reaches the observed concentration (Monte Carlo p = 0.00056). A separate programme-level audit finds that 24 of 33 distinct host-country-by-date approval events for Programmes of Activities (PoAs) coincide with a same-country PA approval date (week-constrained p = 0.0072). Two official exports differ in 145 cells across 37 common records; two newly visible approvals were dated before the national deadline, while one historically irregular activity disappears from the later export without demonstrated withdrawal. The dated national act and its public appearance therefore encode different observables. These results document cross-activity temporal synchronisation and registry-version sensitivity, not collective governmental deliberation, causal approval preferences, or independent UNFCCC receipt timestamps. We propose event-centred reporting that preserves country, activity type, signed date, publication date and snapshot provenance.