I have a huge respect for the dedication that many people have, on the other side of the Atlantic, to photography. You can count them on one hand here. There's less respect for a Magnum photographer in Britain than there is in America. It's a much more postmodern culture here.

Environmentalism is a personal thing - but it's also a planetary thing. It's about making deep connections. But it's also about recognizing the very human connection between species diversification and ourselves.

We create these walls between fact and fiction, but often the difference between the two is as little as that between a real name and a pseudonym. So I'm not sure about those walls - certainly not in the realm of visual arts.

Social media's currency is the single photograph. Whereas, every time I look at a photograph, I look at twenty or thirty photographs. I'm looking for a narrative. And that's a different kind of construct. If you're a poet and you put a line from your poem online, "The trees bending over gracefully," or something, you can get a tick. But that has nothing to do with your longer poem.

Photography for me has been tremendously good, because I'm not a very sociable person. I'm happy reading or sitting in the library or going for walks. So photography has brought me in contact with people and made me understand people in a way that I probably wouldn't have done if I hadn't been a photographer. And so I'm grateful for that, really.

Good photographs aren't just complex. They are enigmatic. Images are beguiling. And the way they play into our psychology, into our visual cortex, is something we still don't understand.

There was as big a reaction after the revelations about Assad's chemical weapons. Nevertheless, that photograph did strike a singular chord. Which leads us to a larger fact: we don't understand why certain photographs create such an upheaval in one's soul. You look at them and go, "Oh my gosh." And that doesn't happen with television. It's unique to photography. Photographs are unique in that they are a frame abstracted out of reality, out of, in this case, a civil war. A single event can carry so much weight. And that is extraordinary.