Of all the creatures in the world that really frighten me - the hyena in Africa, the great white shark - leopard seals are near the top of the list. They're killers. If my team spots one, they'll pull me out of the water.

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.

The importance of music extends well beyond its performance.

When I was born, the world's population was 3.5 billion. There are now 6.8 billion people on the planet. By 2050, that's expected to rise to 9.4 billion. What's more, the Earth's resources aren't growing; they're decreasing - and rapidly.

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.

If you want to swim across the English Channel from England to France - you have to leave your doubt on the beach in England.

If we pass on an unsustainable environment to our children we have failed them.