Silent signals of sustainability: evidence from multi-region visitor reviews of protected areas

This study examines whether consumers notice formal green certifications compared to the implicit conservation signals embedded in online reviws of cross-continental conservation destinations, using Signaling Theory and the Elaboration Likelihood Model. Based on the International Union for Conservation of Nature (IUCN) Green List framework, Good Governance, Sound Design and Planning, Effective Management, and Successful Conservation Outcomes. The study analyzes 11,713 public reviews from Africa, South America (Brazil and Colombia), and Australia. Topic modelling and emotion mining reveal consistent implicit signals (biodiversity, wildlife, clean water, nature reserves) and governance cues (well-managed sites, good guides, safety). Sentiment was largely positive, dominated by joy and trust. Conservation explicitness varied, from subtle in Brazil to moderate in Australia and stronger in Colombia and Africa. These patterns align with Green List principles, suggesting that destinations with stronger governance and management practices naturally generate review language reflecting certification values, even without label recognition. Destination managers and certification bodies should strengthen clear, credible, emotionally resonant signals to connect visitor perceptions with recognised certifications.