There are now more than 4,000 places in the sea around the world that have some kind of protection. The bad news: You have to look hard to find them. What you find instead is destructive fishing, mining, gas and oil exploration.

In terms of personal choices, let's all think more carefully about where we get our protein from.

We have an atmosphere that is roughly 21% oxygen. The rest of it is largely nitrogen. There's just enough carbon dioxide (CO2) to drive photosynthesis. That has been, throughout the history of our species, pretty stable. Until recently.

We couldn't go to the moon on whale oil. We don't have the capacity yet to consider doing such things as harnessing current sunlight. We're burning ancient sunlight in order to get us to where we now are. But it's costly.

Never before have we known what we know.

Ice ages have come and gone. Coral reefs have persisted.

The oxygen cycle, the nitrogen cycle, the carbon cycle, the water cycle - all of these are linked to the existence of life in the sea.