Ultimately I wanted to be a pioneer swimmer, a distant descendant of Scott, Amundsen and Hillary, except that I would be an explorer of the water.

Ultimately I wanted to be a pioneer swimmer, a distant descendant of Scott, Amundsen and Hillary, except that I would be an explorer of the water.

I learned two basic lessons on Everest. First, just because something has worked in the past does not mean it will work today. Second, different challenges require different mindsets.

I think that I was slightly naive. I thought that if I showed people the beauty of the Arctic and the beauty of the polar bears that they would care so much that they would stand up and try to make a change.

There is nothing more powerful than the made-up mind.

The days of exploration of Shackleton and Scott are long gone. Everything has been climbed, crossed, done. Now what we're exploring are the full boundaries of human endeavour. It's not physical - it's all in the head.

Climate change is the Everest of all problems, the thorniest challenge facing humankind.