Researchers found while tourists' core environmental values don't change, travelling can activate a 'vacation place identity' which makes people feel freer and less accountable for sustainable behaviour than at home.
PhD candidate Dorine von Briel from UQ's Business School said the temporary identity switch explains why even conscientious travellers waste more and conserve less when they are away from home.
"We've introduced 'vacation place identity' as a distinct, measurable psychological state that emerges with travel, or even when people mentally step into a vacation setting," Ms von Briel said.
"This contrasts with the more commonly known 'home place identity', which is rooted in routine, responsibility and long-term emotional connection."
Researchers conducted 3 studies and found participants consistently described themselves as less environmentally responsible when on holiday compared to at home.
Dr Anna Zinn said people switching identities is nothing unusual - from work identity to parent identity to national identity - but this is the first study to identify a unique vacation identity and its implications for environmental sustainability.
Previous UQ research has showed tourism is responsible for almost 9 per cent of global carbon emissions, but efforts to encourage more sustainable behaviour among travellers have struggled.
Professor Sara Dolnicar said activating 'home place identity' before departure or during travel could boost sustainable behaviour.
"Sustainability messages often fail because they target tourists when their vacation place identity is already dominant," Professor Dolnicar said.
"Industry and policymakers should rethink timing and tactics for sustainability campaigns.
"Instead of guilt-based messages during trips, like reusing towels or reducing shower times, subtle prompts that evoke our home routines before departure could make a big difference."
The research was published in Tourism Management.
