Some 105.3 million U.S. leisure travelers, or 60 percent of all leisure travelers in the U.S., say that they are “sustainable travelers” — those concerned with how their travel impacts everything from a destination’s local economy to the environment. That’s according to a new study from Mandala Research, a firm that studies unfamiliar or controversial data and trends in the travel industry. The study also found that, ironically, 64 percent of its survey respondents were unsure of what sustainability means when unaided by any definitions. This has long been a challenge in the travel industry. Read more (source: Skift).