I think global warming is a very real problem for our world. I've seen the changes that have taken place in the Antarctic, in the Himalayas, where the natural ice has sort of faded away, and there's no doubt in my mind that we're living in a strange world, a world which is not easy to understand or handle, But there's nothing you can do about, you just have to live your life as best you can.

Challenge is what makes men. It will be the end when men stop looking for new challenges.

I think it all comes down to motivation. If you really want to do something, you will work hard for it.

I was certainly seriously emotionally affected [ when Louise Hillary and Belinda Hillary died], but we were building the hospital at the time and I decided that the only thing to do was to carry on and complete the hospital - and it was a jolly good hospital too, I might say. So I really did it by working and working on the things that Louise and I had been working on.

When you go to the mountains, you see them and you admire them. In a sense, they give you a challenge, and you try to express that challenge by climbing them.

While on top of Everest, I looked across the valley towards the great peak Makalu and mentally worked out a route about how it could be climbed. It showed me that even though I was standing on top of the world, it wasn't the end of everything. I was still looking beyond to other interesting challenges.

I get older I get more cantankerous, but June [Hillary] gets a bit more cantankerous, too.