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.

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.

It's quite difficult to write about photography as a photographer. A lot of better photographers than me have declined to do it.

I think, oddly, that the world of the amateur is quite self-contained, and it depends on "likes" from other amateurs to perpetuate itself. Of course an awful lot of my colleagues are involved with Instagram - they get likes and dislikes, maybe just likes, I don't know - but I think that it's far less self-contained, the world I work in. It goes off in different directions, and is dependent on responses different from a tick or a like or whatever.

We sort of understand how painkillers work. You take one, and it reduces your headache. We don't understand how photographs work. And that, to me, is an essential problem as a practitioner.

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.

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.