Oxygen - A Four Billion Year History [Book Review]

If one could boil all of Earth's behavior down to a single number—a statistic that captured the rich intersection of geological, chemical, and biological processes operating on our planet's surface—a strong argument could be made for the atmosphere's O_2 content. That is presently 21% by volume, but a wide range of data extracted from the geologic record demonstrates that O_2 levels have varied considerably. To first order, Earth's history is written in O_2, and tangled in the story are plate tectonics, the rock cycle, the evolution of photosynthesis, and the appearance of animals. In Oxygen, Don Canfield lucidly unpacks this story through a careful mix of overview and detail, with a focus on the relevant biogeochemical mechanics.