TripAdvisor announced the results of its ecotourism survey of more than 1,000 travelers worldwide. Eleven percent of respondents have taken and one-quarter are considering going on an ecotourism trip. Thirty-eight percent of respondents said that environmentally-friendly tourism is a consideration when traveling.

Thirty-eight percent of travelers surveyed have stayed at an environmentally-friendly hotel, and nine percent specifically seek out environmentally-friendly hotels. When asked what qualities are most important to making a hotel eco-friendly, conserving energy ranked number one, followed by conserving water and using recycled paper.

Seventy-eight percent of travelers said they decline to have their sheets and towels changed, when provided the option by hoteliers.

Sixty-six percent believe environmentally-friendly measures in travel are making a difference.

Thirty-four percent of travelers surveyed would pay more to stay at an environmentally-friendly hotel. Twenty-five percent would be willing to pay a 5-10 percent premium, and 12 percent would pay a 10-20 percent premium.

Twenty-four percent of respondents believe that air travel should be avoided, when possible, to help preserve the environment. Thirty-eight percent of travelers surveyed would pay more to take an eco-friendly flight and 26 percent would pay a 5-10 percent premium. Only three percent of travelers surveyed have purchased carbon credits.

"A significant number of TripAdvisor survey respondents are environmentally-conscious, which sends a message to the travel industry to ratchet up eco-friendly offerings," said Michele Perry, director of communications for TripAdvisor. "Travelers are willing to pay more to be green."