These days, most nature photographers are deeply committed to the environmental message.

My mountaineering skills are not important to my best photographs, but they do add a component to my work that is definitely a bit different than that of most photographers.

There is no question that photography has played a major role in the environmental movement.

Ever since the 1860s when photographers travelled the American West and brought photographs of scenic wonders back to the people on the East Coast of America we have had a North American tradition of landscape photography used for the environment.

The combination of pictures and words together can be really effective, and I began to realise in my career that unless I wrote my own words, then my message was diluted.

The reason that I keep writing is that all my most powerful messages about the fates of wild places that I care about need to have words as well as images.