Why is it that scuba divers and surfers are some of the strongest advocates of ocean conservation? Because they've spent time in and around the ocean, and they've personally seen the beauty, the fragility, and even the degradation of our planet's blue heart.

We woke up some years ago about the consequences of ozone depletion, the hole in the atmosphere. You can't see it. You can't taste it. You can't smell it. But now we do regard that as a key issue. It's a scientific finding.

In the past few decades, Earth's natural systems have endured more pressure than in all preceding human history.

If you think the ocean isn't important, imagine Earth without it. Mars comes to mind. No ocean, no life support system.

It isn't too late to shift from the swift, sharp decline of ocean systems in recent decades to an era of steady recovery. There is time, and there is a growing awareness, which is the best way to counter indifference. People who know might care.

The observations that have developed over the years have given us perspective about where we fit in. We are newcomers, really recent arrivals on a planet that is four and a half billion years old.

That attitude of arrogance, that attitude of "It's all about me. It's all about what I can get out of life now" - well, I'm personally driven by wanting to get out of my life the best I can achieve as a gift for those who come after me.