The Thin Layer of Us

I sometimes wonder if we have, as humans, forgotten how totally inconsequential we are in the grand scheme of, well, everything. In Peter Brannen’s The Ends of the World: Volcanic Apocalypses, Lethal Oceans, and Our Quest to Understand Earth’s Past Mass Extinctions, he places humanity within the almost incomprehensible scale of geological time.1 Brannen argues that humanity’s presence on Earth is almost imperceptibly brief when viewed against that scale. Human beings tend to interpret the planet’s history as though our arrival were its culmination, but Earth existed for billions of years before us. Entire biological worlds appeared, persisted, and disappeared over spans of time vastly longer than the whole of human existence. Modern Homo sapiens have existed for only about 300,000 years, while geological periods and biological communities persisted for tens or hundreds of millions of years.2 From the perspective of Earth history, human civilization represents only the thinnest and…