Marcia Bjornerud's "Timefulness"

Marcia Bjornerud is the Walter Schober Professor of Environmental Studies and Professor of Geology at Lawrence University. She is the author of Reading the Rocks: The Autobiography of the Earth and a contributing writer for Elements, the New Yorker’s science and technology blog.

Bjornerud applied the “Page 99 Test” to her new book, Timefulness: How Thinking Like a Geologist Can Help Save the World, and reported the following:

From page 99 of Timefulness:

There were oceans on this ancient Earth, and the nearness of the Moon would have made tides significantly higher. Tides would also have been more frequent, because the day was shorter, probably less than 18 hours (making a year of about 470 days). Over time, friction between the ocean-atmosphere system and the solid Earth has acted like a soft brake that has gradually slowed the planet’s rotation.

Page 99 falls in the early part of a chapter called “Changes in the Air”, about the evolution of the atmosphere and ocean over geologic time. My hope is that by taking a deep dive into the story of the atmosphere, readers might better appreciate each breath they take and understand that the clement and hospitable conditions that prevail today on this planet are not the only mode Earth has.

A central idea in the book is that Earth and Life have co-evolved, and that as long as the surface environment has not changed too quickly, lifeforms have been able to adapt. Occasionally, however, a rogue asteroid or a ‘perfect storm’ of internal factors has led to such rapid changes in climate, atmospheric composition, and/or sea level that the biosphere has not been able to keep pace. These mass extinction events are sobering reminders that there are limits to life’s resilience -- and cautionary tales for a species that is cavalierly altering the atmosphere and hydrosphere at rates almost unprecedented in Earth’s history.

More broadly, understanding the history of the atmosphere is part of “Timefulness” – seeing the back stories that are embedded everywhere in the natural world, and shifting our perception of our place in the cosmos.

Learn more about Timefulness at the Princeton University Press website.

--Marshal Zeringue