"I don't think you should sleep well if you spend $500 a night at some fancy resort that has essentially eliminated a species which lived there before," Sweeting adds. "If golfers said, 'I'm not coming to play your course because you destroyed the local ecosystem when you built it,' we would see a quantum shift" in resort development practices.

But others, including Ronald Sanabria, director of sustainable tourism at the Rainforest Alliance, recommend a different approach. "You might find a hotel in a very fragile ecosystem that is taking action in all the things a hotel can possibly do to contribute to the environment," Sanabria says. "If that business, through tourism, is helping to protect that site and you discourage people from going there, then you can have a greater problem. We've seen that throughout Latin America: If it wasn't for tourism, we wouldn't have some of these sites anymore." As an example, he points to Costa Rica's Lapa Rios Ecolodge, where, he says, hundreds of pristine coastal acres would have become cattle farms were it not for the support of ecotourists. Sanabria recommends that travelers planning a trip inquire about a facility's current environmental practices, such as energy-saving measures and waste-disposal systems, and look for eco-credentials such as Green Globe or Smart Voyager certification. By focusing on what a resort or cruise line is doing right today rather than on what it did wrong in the past, he says, travelers can support sustainable practices and even help improve places blighted by prior negligence.

For all their differences, however, experts stand together on a few major points. They emphasize the need for questioning airlines, hotels, car rental agencies, and other businesses about their environmental practices, to make clear that the subject is important. When possible, they suggest, go with environmentally certified operations. And, they insist, green habits can make trips, even luxurious ones, more satisfying. "If you do things that bring environmental and social benefits to the place, you usually end up with a better vacation," Honey says.

The road to environmentally responsible travel for all is still a bumpy one, sort of like the drive to the Hotel Eco Paraíso Xixim. But fortunately it's slowly getting smoother, because if anything is sustainable in the long run, it's the demand for journeys that truly satisfy.