What is a sustainable human population? Chris Tucker, author of A Planet of 3 Billion, joins us.

We’re asking the Earth to support 80 million more humans every year, and we add to the challenge by deleting some of the needed resources from the planet each year. Meanwhile, too few us ask the question, “What is a sustainable human population?” Christopher Tucker did ask the question, went to work on it, and wrote a book about it: A Planet of 3 Billion: Mapping Humanity’s Long History of Ecological Destruction and Finding Our Way to a Resilient Future. He came up with an “optimistic” answer of 3 billion. This episode features the first half of an insightful conversation we recently had with Tucker. Our discussion includes why he avoids using the term “overpopulation” (and why we DO use it), how and why the taboo on discussion of this topic came about, and the beautiful way we can bend the curve of human population numbers. How does achieving a global average fertility rate of 1.5 by 2030 sound? Is that really so crazy? Tucker points out this is just accelerating a norm shift that’s already underway.

Christopher Tucker is chairman of the American Geographical Society, and strategic advisor to the US national security community. He holds a BA, MA, and PhD from Columbia University. Chris serves on a number of boards including the United States Geospatial Intelligence Foundation and the Open Geospatial Consortium.

See episode website for show notes, links, and transcript: https://www.populationbalance.org/podcast/christopher-tucker1

 

ABOUT US

OVERSHOOT | Shrink Toward Abundance [Formerly The Overpopulation Podcast]

OVERSHOOT tackles today’s interlocked social and ecological crises driven by humanity’s excessive population and consumption. The podcast explores needed narrative, behavioral, and system shifts for recreating human life in balance with all life on Earth. With expert guests from wide-ranging disciplines, we examine the forces underlying overshoot: from patriarchal pronatalism that is fueling overpopulation, to growth-biased economic systems that lead to consumerism and social injustice, to the dominant worldview of human supremacy that subjugates animals and nature. Our vision of shrinking toward abundance inspires us to seek pathways of transformation that go beyond technological fixes toward a new humanity that honors our interconnectedness with all beings. 

Hosted by Nandita Bajaj and Alan Ware. Brought to you by Population Balance. 

*Episodes from 2016-2021 were hosted by former executive director Dave Gardner and later with co-host Erika Arias, and then with co-host Nandita Bajaj.

Learn more at populationbalance.org

Copyright 2025 Population Balance