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Timefulness: How Thinking Like a Geologist Can Help Save the World

Marcia Bjornerud
Princeton University Press
218 pp.
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Earth, according to Marcia Bjornerud, is proportionally analogous to a peach. The pit is the core; the fruit is the mantle; the skin is the crust. And peach fuzz? It’s the thickness of the atmosphere.

This is one example of the many wonderful analogies Bjornerud uses in Timefulness to help readers understand subjects ranging from Earth’s structure to the concept of geologic time. Bjornerud’s thesis is that having more people who can think like a geologist, rising above day-to-day concerns to conceive of the long-term consequences of our actions, will help society overcome many problems we face.

Bjornerud, an experienced field geologist, opens with a story about her first field research site on the Arctic archipelago of Svalbard, a location so remote and austere that it appears timeless. (Indeed, Svalbard literally has “No Official Time” because of a long-standing border disagreement.) It is from this benchmark that she gained an appreciation for the passing of time—a theme built on throughout the remainder of the book.

Bjornerud has a yeoman’s command of historical geology, which she executes by moving through the evolution of our understanding of the age of Earth. She traces the postulations of Charles Lyell, James Hutton, and others, then moves on to the discovery and application of modern radiomentric dating and chronostatigraphy. She writes of the human aversion to the passage of time, which she terms “chronophobia,” as epitomized by our narcissism and our obsession with defying our own ages.

Bjorneurd displays her wit in clever subchapter titles and headings. “Peak performances,” for example, cheekily introduces a discussion of how erosion paradoxically causes mountains to rise in elevation. Quotes from ancient philosophers and notables throughout history add color and levity, while salient storytelling keeps the narrative informative without being tedious.


A research trip to Svalbard impressed upon Marcia Bjornerud the amorphous nature of time.

Black-and-white, hand-drawn sketches illustrate geologic concepts throughout the book. Although the figures complement the conversational writing style, they may be a bit hard to comprehend for those with less than a basic understanding of geology. One figure, for example, illustrates a distant view of a tidal flat featuring algal stromatolites. A block diagram with wavy lines represents a fossilized sample in the foreground. It may be difficult for nongeologists to ascertain how these two images interrelate.

Still, Timefulness is a delightful and interesting read. The author’s cadence and the illustrator’s aforementioned figures made me feel as though I was having a glass of wine with a friend who was explaining geologic history while sketching on a napkin.

Will Timefulness help save the world? Only time will tell.

About the author

The reviewer is at the Delaware Geological Survey, University of Delaware, Newark, DE 19716, USA.