Nothing better encapsulates the challenge of finding reliable information on environmentally sustainable travel companies than the various attempts to establish green certification for hotels and tour operators. In recent decades, such schemes have exploded across the globe—from around a dozen in 1990 to more than 70 major eco-labels today, with hundreds of tiny ones further crowding the field. Some, like the Green Globe program, operate internationally under their own auspices as nonprofit or for-profit enterprises; others are run by national, state, or local governments, by trade associations, or even by the very companies they claim to certify. In theory, eco-labels simplify the decision-making process for people seeking to travel green; in practice, however, they tend to raise more questions than they answer. With so many labels out there, it's hard to know which ones to trust; some are less rigorous than others, each has its own criteria—and some of the best have more than one level of certification, making the process even more opaque. A property whose minimal practices earn it an entry-level rating, for example, can be entitled to the promotional use of a logo that's barely distinguishable from the one awarded to a full-scale eco-resort. But the biggest problem with certification is that there are many excellent, sustainably operated properties that don't have the manpower or considerable finances to participate in the process. The bottom line is, even if eco-certification were 100 percent reliable (a big if, to say the least), limiting yourself to certified destinations would mean ignoring many of the planet's best green-travel experiences.

It's not a traveler's job to be an expert inquisitor; if a hotel or a resort is engaged in good practices, it will be only too happy to tell you about them. In fact, one potential red flag doubles as a convenient time-saver: If the hotel employee who answers the phone can't answer your questions about its environmental bona fides, be skeptical.

Reasonable expectations can change, depending on the part of the world you're visiting, as well as the price point and the size of the provider. If you ask the staff at little Ojo del Mar (Lapa Rios's $45-per-night neighbor) what makes the hotel green, they will eagerly tell you about the decision to build the facility out of local bamboo rather than the cheaper bamboo imported from Colombia—and how they've used the opportunity to help the local cooperative understand how to better compete with the imports. That's something you won't find on any checklist—proving that you don't have to be rich to operate your hotel in a way that benefits the local environment and economy.

Evaluating environmental impact can be tough, admittedly—especially for a casual traveler, and especially over the phone. One helpful shortcut for identifying responsible operators is to ask what community development initiatives a hotel is involved in. Ultimately, supporting the community goes hand in hand with any real green agenda, and it's a reasonable bet that a company which takes good care of its people is also likely to be doing its best on the environmental front.

"I think it really boils down to one question: How does a business contribute to the conservation of the local community?" says Ronald Sanabria, of the nonprofit Rainforest Alliance. "If a business—even one in a city—can't provide you with a concrete response, it's not practicing ecotourism and there is no substance to any claim that it is. It's up to the consumer to decide if that's acceptable."