Yann Arthus-Bertrand is a French photographer, journalist, and environmentalist who founded an aerial photography agency in 1991. In 1994, he started a study for UNESCO on the state of the Earth, taking aerial photographs of landscapes from helicopters and hot air balloons in over 100 countries. The resulting book, Earth from Above, sold over 3 million copies and was translated into 24 languages. In 2000, his free exhibition of photographs from the project displayed on posters in Paris was visited by 120 million people as it traveled to 110 cities worldwide.