Costas is one of the world’s top sustainable travel experts, whose work has taken him to more than 130 countries across six continents. He is an award-winning writer and editor at large for National Geographic Traveler magazine and serves as a Senior Advisor to National Geographic Travel. Costas was honored along with Conservationist Dr. Jane Goodall, Oceanographer Dr. Sylvia Earle, and CNN Founder Ted Turner for his work as an ecotourism pioneer. NBC News said: "For the past 30 years, Costas Christ been at the leading edge of the green travel movement, since way before it was ever called green or even a movement." Costas is the Global Sustainability Strategist for Virtuoso, one of the world’s largest travel associations. He has worked extensively to advance the protection of natural and cultural heritage. He is the lead author of Tourism and Biodiversity, and a contributing author to Wilderness: Earth's Last Wild Places, Transboundary Conservation: A New Vision for Protected Areas and Echoes of Bhutan. His travel stories and essays have appeared in the New York Times and the Sunday Times. His TV and radio appearances include Travel Channel, Good Morning America, BBC World, CNN International, CBS and National Geographic Channel.