Is that hotel truly sustainable - or are you being greenwashed?

Ditching plastic straws and hanging a "save your towels" card won't cut it anymore.

In an era where every second hotel claims to be "green," separating authentic eco-warriors from clever marketing is a minefield for conscious travellers.

Sustainability isn't a single checkbox - it's a spectrum. Here is how to tell if your hotel is actually walking the walk.

Ecotourism Australia chief executive officer, Elissa Keenan, says Ecotourism Australia's Sustainable Tourism Certification encompasses responsible practices across four pillars: environmental, socioeconomic, cultural and sustainable management.

"Global research consistently shows that travellers increasingly value verified sustainability claims and that visitors want confidence that their travel choices protect nature, respect cultures and contribute positively to local economies," Keenan tells Explore.

Keenan says broad or vague terms like "green", "eco-friendly" and "sustainable" are considered misleading unless they are clearly defined, evidence-based and independently verified through a third-party audit.

Griffith Institute for Tourism professor of sustainable tourism, Susanne Becken, says a sustainable hotel is one that understands its role in the wider destination.

"That means that it does not only have responsibility to minimise its own footprint (ideally become zero carbon, circular, a good employer) but it contributes actively to the local fabric of the community and environment," Becken says.

"This means purchasing local, supporting social initiatives, contributing to nature restoration. It's a system approach. What might look like an additional cost is essential for place making, resilience, and ultimately business longevity."

If a guest opens their hotel room door, there are things to immediately look for to ascertain whether a hotel is taking steps towards sustainability.

"Consistency is number one," Becken says. "If the hotel claims to be sustainable (and maybe they don't do plastic straws) but there is evidence of clearly unsustainable practices (for example plastic bottles in the minibar) it indicates that the hotel focuses on a small number of initiatives but not a whole-of-business design."

Air conditioning is the single largest source of energy demand in a guest room.

"Some rooms do not allow the customer to adjust the settings meaning that electricity use can not be reduced by an eco-conscious traveller. Rooms that allow you to open the window, have a ceiling fan, and don't run the aircon at full strength are a good sign," Becken says.

Working with local producers is also important, for example providing locally made biscuits, coffee and milk.

University of Queensland professor in tourism, Sara Dolnicar, recommends asking the hotel front desk about their sustainability practices.

Ecotourism Australia has an online Green Travel Guide at www.greentravelguide.org which lists every ECO Certified and Sustainable Tourism Certified operator and destination in Australia.

Travellers can also look for indicators such as the Travel Sustainable badge on Booking.com listings or the Eco-certified badge on Google, and book with businesses that hold globally recognised sustainability certification.

These labels can be used as a filter in search results.