From Claim to Proof: A Systematic Review of Greenwashing, Certification and the Regulatory Substantiation Turn in Tourism and Hospitality, 2024–2026

Abstract

Sustainability communication in tourism has entered a regulatory phase. Between 2024 and 2026 the European Union’s Directive (EU) 2024/825 on empowering consumers for the green transition moved unsubstantiated environmental claims from the domain of marketing ethics into the domain of consumer protection law, with national transposition due by 27 March 2026 and full application from 27 September 2026. This review asks what the peer-reviewed literature published in that same window tells us about how tourism and hospitality firms produce, verify and communicate sustainability claims, and how far that literature is prepared for a regime in which claims must be proven rather than asserted. Following PRISMA 2020, thirty-one studies published between 2024 and 2026 in ranked tourism, hospitality and management journals were synthesised using a framework approach. Five thematic clusters were identified: the antecedents and organisational drivers of greenwashing; consumer processing of claims, labels and information volume; the ambivalent performance of third-party certification; greenhushing as a strategic response to regulatory risk; and the largely unexamined question of verification quality. The review proposes the Substantiation Regime Model, which distinguishes three tiers of claim credibility, assertion, substantiation and independent verification, and introduces the construct of verification asymmetry to describe the systematic gap between large branded operators and small and medium-sized tourism enterprises in the capacity to move up those tiers. The review finds that the field has studied claims and their reception extensively but has almost never audited the verification infrastructure on which the new regulatory regime depends. Six research propositions and a research agenda are advanced. The findings are particularly consequential for destinations in the Global South whose outbound-facing operators sell into European markets while operating under voluntary and fragmented national certification arrangements.