After the Spike: Population, Progress, and the Case for People
Dean Spears and Michael Geruso
Simon & Schuster (July 2025)

Why responding to depopulation will be more challenging than responding to climate change

At the outset, Dean Spears and Michael Geruso identify three “big claims”:

1. “No future is more likely than that people worldwide choose to have too few children to replace their own generation. Over the long run, this would cause exponential population decline.”

2. “A stabilized world population would be better, overall, than a depopulating future.”

3. “Nobody yet knows how to stabilize a depopulating world. But humanity has made revolutionary improvements to society before — we can do it again if we choose.”

To what does the title of this book refer?

Spears and Geruso explain: “The Spike is not a product of outlandish imagination. The possibility it charts does not assume some shift o® reversal in the way people live and believe. The Spike is what would happen if the whole world one day had the sort of birth rates that are already in common in many places. In that future, like now, some people would have a few children. Some would have none. And many would have one or two.

“We generated the Spike by projecting a future in which, globally, there were 1.6 billion children per pair of adults, a statistic that matches the current U.S. average. But, as we’ll show soon, something like the Spike will happen as long as the worldwide average stays below two children per pair of adults. Below two children is what matters, because it means that one generation isn’t replacing itself in the next generation.”

They then ask, “Is that kind of future likely?” That is indeed a key question to keep in mind.

Many readers will say that this book changed their perspectives on population and depopulation issues. I am among those readers who are embarrassed to acknowledge that   After the Spike got us to thinking about those issues for the first time. (Just in time for me. I  will celebrate my 90th birthday next March.) Thanks to Spears and Geruso, I am now beginning to understand why responding effectively to depopulation will be — or at least could be — more challenging than responding to climate change.

Of all the dozens of other key questions to which they also respond, these caught my eye:

o”What are the most significant benefits of stabilization?” (Check out Pages 58-72, 117-136, 137-156, and 216-223.)

o “What are the most significant benefits of depopulation (See Pages 49-68, 124-125, 145-146, and 157-158.)

o “What does the Repugnant Conclusion tell us about preferring either stabilization or depopulation?” (See Pages 261-272 and 290-291.)

I urge everyone who reads this brief commentary to obtain a copy of After the Spike ASAP and read, then re-read it. Meanwhile, here are some final thoughts provided by Dean Spears and Michael Geruso. Absorb and digest them with meticulous care…and with profound gratitude:

‘Let’s talk. Let’s think big. Waiting until after the  Spike to learn how to respond to depopulation would be as imprudent as waiting until we burn the last ounce of coal to begin responding to climate change or waiting until a new disease emerges to develop the science of mRNA vaccines. Climate change taught us to accept that importance can come with uncertainty, and that uncertainty doesn’t relieve us from a duty to hope, learn, and organize. Humanity is on a path to depopulation. That calls us [as has happened so many times in years past] to hope, learn, and organize again.”

Who or what can prevent us? I agree with Pogo the Possum: “We have met the enemy and he is us.”

* * *

Here are two suggestions while you are reading After the Spike: First, highlight key passages. Also,  perhaps in the notebook that you should always keep near-at-hand (e.g. Apica Premium C.D. Notebook A5), record your comments, questions, and action steps (preferably with deadlines). Pay special attention to the uniquely innovative “Figures” strategically inserted throughout the narrative as well as to the insightful observations that conclude each of the twelve chapters.

These two simple tactics — highlighting and documenting — will expedite frequent reviews of key material later.