After the Spike

Brought to you by Penguin.

An eye-opening exploration of humanity’s unprecedented path to global depopulation and why it''s in everyone''s interests to prevent it

IIf we continue as we are, with birth rates falling globally, the world’s human population will peak in the next few decades – and then begin a sudden and rapid decline. It would be easy to think that fewer people would be better: better for the planet, better for the people who remain. In After the Spike, two leading population economists ask us to think again.

Carefully weighing the evidence and the many claims that surround this controversial subject, Dean Spears and Mike Geruso explain why depopulation is not the solution we urgently need for the climate crisis, nor will it improve lives. Far more likely is that the progress which has raised living standards so dramatically over the last two centuries will slow or even reverse. As humanity’s future shrinks, it will become more fragile and less certain, and harder for us to escape from global poverty, disease and injustice.

Halting this decline and stabilising the population need not mean sacrificing a greener future or reverting to past gender inequities. In fact, they argue, it can only be achieved with women’s reproductive rights and individual choice as driving forces. But if we want future generations to enjoy lives even better than our own, it’s time to take seriously society’s collective task of lifting the burdens of parents and other carers.

Deeply reasoned and uncompromisingly humane, After the Spike sheds important light on a dramatic shift in the human story and asks us to consider what future we should want for our planet, our children, and one another.

© Dean Spears and Michael Geruso 2025 (P) Simon and Schuster LLC 2025