THE ENVIRONMENTAL FILM FESTIVAL is one of the world’s largest and most influential showcases of environmental film and a major collaborative cultural events in Washington, D.C. The Festival presents a diverse selection of environmental films screened at partnering museums, embassies, libraries, universities and local theaters. Most films are accompanied by discussions with filmmakers, environmental experts and guests, including national decision makers and thought leaders, and are free.
Cinemambiente 2013 - Opening Titles by Housedada. Since its debut in Turin in 1998, CinemAmbiente – Environmental Film Festival has presented outstanding environmental films in a year-round program of initiatives that promote cinema and green awareness.
The 30th International Environmental Film Festival is held in Paris 19-26 February 2013. FREE entry. I've attended this film festival several times and have seen excellent films. Definitely worth a go, and the event website is very well organized.