Q. With five years of filming and umpteen helicopter rides, the "carbon footprint" of this film had to be fairly significant. Did you try to calculate or offset the impact?
A. It's fair to say you can't make a movie like this without burning quite a lot of fossil fuel, (but) we tended to work with very small crews, rarely bigger than two. This isn't a heavy-handed environmental film — it's not An Inconvenient Truth. But we have heard that lots of people have been inspired by it, and motivated to preserve the planet.
Q. Speaking of being motivated and inspired, why were so few locations identified in the film?
A. It's not a travel show. Our story was about the animals: We didn't want a lot of narration, and we wanted the pictures, music and sound to tell the story.
Q. Identified or not, what percentage of the places you filmed are accessible to normal travelers?
A. It's easily 50% — and I think that's very good news. A lot of wilderness areas are in Third World countries, and the income that ecotourism brings there is vital. Where we filmed the cheetahs in Masai Mara, in Kenya, there's no doubt that without tourism, that wouldn't still be a national park.