RETHINKING THE STORY OF EARTH
It is easy to regard oxygen as an essential gas that constitutes about 21% of our atmosphere. This is .0001% of the whole story. The remaining 99.9999% of the earth’s oxygen is locked up in rocks and minerals. Most of the atoms in the rock shown in the photograph above are oxygen. It turns out that the business of getting free oxygen into the atmosphere – and keeping enough of it there to support life – is the end-result of a complicated narrative that as far as we know has not played out anywhere else in the universe.
This remarkable story, which begins 4.567 billion years ago with the formation of our solar system, reveals that the evolution of the earth was influenced by the evolution of life in much the same fashion that the evolution of life was influenced by the evolution of the earth. Life and earth coevolved. The Story of Earth, a highly recommended book written by Robert M. Hazen, explores the unique connection between life and earth. While there are only a dozen or so minerals in the dust and gas that became our solar system, there are more than 4,500 known mineral species on earth, two-thirds of which could never have existed in a dead world. According to Hazen, many of these minerals were a consequence of life, and the minerals in turn provided life new sources of chemical energy and exploitable niches in which to advance.
Hazen also points out that the story of earth comfortably accommodates a great deal of insult and disaster, and that countless times throughout its history earth has survived catastrophe far worse than anything mere humans could ever perpetrate, propagate, or perpetuate against it. The earth does not need saving. We do. We are nowhere near as resilient as our planet, and our presence here is a revocable privilege, not a right.
Scott Adams, formerly an earth scientist with Chevron, will present a lecture on The Story of Earth which is based on Hazen’s book.