(Paperback)

(Hardback)

The air we breathe is twenty-one percent oxygen, an amount higher than on any other known world. While we may take our air for granted, Earth was not always an oxygenated planet. How did it become this way This title tells an account of the history of atmospheric oxygen on Earth.

(Paperback)

The air we breathe is twenty-one percent oxygen, an amount higher than on any other known world. While we may take our air for granted, Earth was not always an oxygenated planet. How did it become this way Donald Canfield--one of the world's leading authorities on geochemistry, earth history, and the early oceans--covers this vast history, emphasi