So let's raise the tone of the debate. Too often at the moment we look like schoolchildren squabbling over a toy - our most precious toy, the Earth. And the danger is that as we pull in opposite directions in our global tug of war, the Earth will end up broken - or at least unable to sustain human life. That is the worst case scenario - or maybe, from the Earth's point of view, the best.

Compared with the awesome might and eternal power of the ocean, no human being can fail to be reminded of their own insignificance.

Be mindful of the link between present action and desired future outcome. Ask yourself: if I repeat today’s actions 365 times, will I be where I want to be in a year?

Despite what I had acchieved, I don't for a moment think I am any braver or better than anyone else. This is how I attempt to explain what gives me the stregnth to do what I do; when that thunderbolt of an idea first hit me and inspired me to row across oceans, it filled me with a sense of purpose so strong that it overcame my fears. Even when boredom, frustration, fatigue or despair threatened to overwhelm me, it was that powerful sense of purpose that kept me going.

The bigger the challenge, the bigger the sense of accomplishment when you get to the end of it.

A few years ago I wrote two versions of my obituary, the one I wanted and the one I was heading for. They were very different. I realized I needed to make some big changes if I was going to look back and be proud of my life. I am making those changes, and now I have a life worth living.

I just used to have a really normal life, working in an office.