Carbon markets face a growing permanence challenge. As crediting scales up, the consequences of reversal become more significant — yet approaches to managing reversal risk remain inconsistent, empirically weak, and increasingly misaligned across major programmes. This report assesses how reversal risk is handled across CORSIA, PACM, EU CRCF, ICVCM, and leading private standards, identifies where current tools fall short, and sets out concrete recommendations for programmes, policymakers, and buyers.