Ten percent of the big fish still remain. There are still some blue whales. There are still some krill in Antarctica. There are a few oysters in Chesapeake Bay. Half the coral reefs are still in pretty good shape, a jeweled belt around the middle of the planet. There's still time, but not a lot, to turn things around.

Historically, girls have not been encouraged to be scientists, to be explorers, and there's a social kind of constraint, of course. Having the responsibility, a disproportionate part of the responsibility, for caring for families, caring for children. I know this challenge from firsthand experience because I have three children and four grandsons.And some of the time I have spent as a scientist and as an explorer has meant choosing to not be with my children and grandchildren as much as I might otherwise have done had I not been a scientist, an explorer.

The end of commercial fishing is predicted long before the middle of the 21st century.

We have been far too aggressive about extracting ocean wildlife, not appreciating that there are limits and even points of no return.

We have become frighteningly effective at altering nature.

Most of life on Earth has a deep past, much deeper than ours. And we have benefited from the distillation of all preceding history, call it evolutionary history if you will.

'Green' issues at last are attracting serious attention, owing to critically important links between the environment and the economy, health, and our security.