Carbon data is becoming a buying criterion in travel ads

The shift in traveller behaviour

Booking.com's Sustainable Travel Report 2026 found that 42% of Dutch and 38% of German travellers say carbon impact is now a significant factor in their destination choice. Five years ago it was 12%.

The shift is most pronounced for short-haul European travel where train alternatives exist, and least pronounced for long-haul where the choice is essentially binary.

The ad-tech catching up

Three things matured in 2025-26: standardised carbon footprint APIs (IATA's Travel Impact Model, Google's Travel Sustainability data), creative auto-personalisation that swaps copy based on origin-destination carbon profile, and consumer-facing carbon labels in Booking.com and Skyscanner.

What's still missing: a standard for measuring the carbon footprint of the advertising itself. Spalder is piloting one this season.

What destinations should do

Don't lead with carbon — lead with experience and let carbon be a tie-breaker. Highlight train accessibility, low-impact accommodations and shoulder-season options in your creative, but keep the message about why someone should visit, not why they shouldn't.

And measure: which audiences engage more with low-carbon framing? Often it's a smaller, more affluent segment that converts better.