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.

The world of photography is very self-aware. Everybody is always looking around. So it's quite difficult to stand up with a megaphone and declare, "This is what I think." As a reasonably shy person, I found it difficult to do that.

We don't understand what photography is doing. We don't understand the power of its rhetoric. We don't understand why the Provoke photographers showed Tokyo city as a ghastly and alien city when it was really going through this period of mega-capitalist growth. It's a very, very, very powerful force, the photograph. People ask me why it has such an ability to captivate us. And I just don't know.

It's certainly important to include text beside documentary photographs. Furthermore, it's important to include text in a way that's useful and accessible.

There is a danger in our modern practice of using embedded journalism. As there is less and less money available for journalism to uphold its independence, there is a temptation for people to take short cuts. If this army or that army or this corporation is willing to pay for your flight or your accommodation, then it's much more difficult to tell what the real story might be. I do have a concern about that.

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.

There was a time, right up until the end of the Second World War and beyond, when white people in Europe thought that they basically owned the world and that everybody else was a sort of servant, or a curiosity, or whatever. And that informed 99 percent of the photographic practice that was done. Without being able to address that, I felt I would have failed in my attempt to explain what the urge to document is.