There is a glacier in Iceland, Solheimar, which has retreated a great deal, and every time I go back there and see what's not there any more, it does something to the heart. It makes you realise it's possible for a gigantic natural element to just disappear.

The problem is almost everybody is just recording the world with home photographic toys, not doing metaphor or ideas. We have a photographic culture that's not conditioned to think in terms of symbol.

You can't divorce civilization from nature - we totally depend on it.

I have often thought that my work with wildlife taught me the meaning of patience, and my work with the big trees taught me the meaning of humility, and my work with the ice has taught me the meaning of mortality.

I've been to the Himalayas a half a dozen times and I love it. I'm just kind of tired of going literally twelve time zones around the world. I would rather go six time zones and get to Iceland or whatever it is.

Each of us can and must shift our behavior according to our ability. For some, that means changing diet, shopping locally, or putting solar panels on their house. For others, it means using their voice to inspire transformative change.

I was raised a Catholic as a boy and went to a Catholic boys' high school, a private school, and kind of drifted away, candidly, in my latter teen years. I consider myself deeply spiritual but not in an institutional, religious kind of a way. In Catholicism, we're surrounded by these images of martyrdom and doing penance and doing some suffering to achieve what you're trying to achieve. And I certainly embedded that in my psyche and I have lived that very effectively.