Last year, I told you about e²: the economies of being environmentally conscious. The series is back for its second season, and will feature two sections: e²: design and e²: energy.

e²: design will again be hosted by Brad Pitt. It will feature such figures in the world's eco-conscious design world as Thom Mayne, architect of the San Francisco Federal Building; Enrique Peñalosa, the former mayor of Bogotá, Colombia; and Adriaan Geuze, lead architect of the Borneo Sporenburg development in Amsterdam.

e²: energy will be hosted by Morgan Freeman, and will feature Muhammad Yunus, Nobel Peace Prize winner and founder of the Grameen Bank; Amory Lovins, founder of the Rocky Mountain Institute; and Dr. José Goldemberg, Brazil's former secretary for the environment.

You can view a webcast of each episode for a week before it airs on PBS. The first episode was put on the e² website today and will run through the show's airing next Friday. I can't find when WGBH will air it, so the webcasts may be the best bet.

You can also watch trailers, podcasts and more on YouTube.