by Marcia Bjornerud
The author’s premise is that understanding the geologic processes and eras in the long history of the Earth can provide a view that no other science can. To that end she covers a wide range of material in this short book, including the carbon cycle of our planet and the major extinctions of life. She explains the role that carbon imbalances played in all the great extinctions, even that of the Jurassic when an asteroid that slammed into Earth played a major role. While some of the material is difficult, she understands that and advises readers, for instance, that that they can skip the part of the book dealing with carbon isotopes. She also has a knack for illustrating geologic concepts with easy-to-understand comparisons. The entire point is that timefulness can make it apparent that upsetting the carbon balance of our world will have catastrophic effects, and that we ignore this to our peril.