The Population Factor

In 2021 TOP co-PI Phil Cafaro finished recording the second season of a new TV show airing on the Internet TV network Earthx TV. The Population Factor aims to become the spot for honest and probing discussion of population issues in the English speaking world. Each show features in-depth conversations focused on a particular aspect of the population/environment connection. Check out seasons one and two, fourteen shows total, all available for free streaming on your TV or computer.


Season 2

Episode 1. Half-Earth: a bold new conservation proposal

Wildlife populations are dwindling rapidly across much of the world, and the number one cause is habitat loss. We discuss a bold new proposal to arrest this decline by dedicating half of Earth’s lands and seas as protected areas, free from intensive human economic use. With Amy Lewis, Vice President of Policy and Communications, the Wild Foundation.


Episode 2. Moving Upstream

Environmental organizations around the world are stuck treating symptoms, rather than addressing the root causes of environmental problems. Naturalist and author Karen Shragg discusses how “moving upstream” and addressing root causes, including excessive human numbers, can invigorate the environmental movement. With Karen Shragg, Director, Woods Lake Nature Center, Richfield, Minnesota, and author of Move Upstream: A Call to Solve Overpopulation, and  Nature’s Yucky! Gross Stuff That Helps Nature Work.


Episode 3. The Making of 8 Billion Angels

8 Billion Angels is a controversial and timely film that asks the question, “Are there too many of us for planet Earth?” Director Terry Spahr joins Phil for a discussion of some inconvenient population truths, and a master class in storytelling on the big screen.


Episode 4. How should environmentalists think about immigration?

Many environmentalists are conflicted about the issue of immigration, caught between a desire to limit national populations and a desire to help poor people overseas live better lives. We explore the need for a US immigration policy that is both compassionate and environmentally sustainable. With Madeline Weld, President, Population Institute Canada.


Episode 5. Planetary boundaries and human numbers

Planetary boundaries is a popular new framework for thinking about humanity’s environmental challenges. This episode explores the question of what role, if any, limiting human numbers should play in helping humanity stay within the boundaries for safe human use of the biosphere. With Kerryn Higgs, author of Collision Course: Endless growth on a finite planet and Fellow with the International Centre of the Club of Rome.


Episode 6. Are aging populations a problem? The case of Japan

Despite the fact that the global population is growing by 80 to 85 million annually, news stories are more likely to focus on the dangers of declining populations. But are national population declines a cause for worry? We explore this question with a focus on Japan, whose population has shown a small decline in the past decade and is on track for much larger declines if current demographic trends continue. With Peter Matanle, Senior Lecturer in Japanese Studies, University of Sheffield.


Episode 7. Is America Overpopulated?

Author and environmental activist Frosty Wooldridge thinks so. He discusses his new book, America’s Overpopulation Predicament: Blindsiding Future Generations. What are the arguments for and against the notion that America is overpopulated?


Season 1

Episode 1. Introducing “The Population Factor”

A wide-ranging conversation with an environmentalist legend, Paul Ehrlich, touching on the history of the IPAT equation along with the history of population concerns and overpopulation denialism.


Episode 2. Population and climate change

Climate change is the leading environmental challenge facing humanity today. How do human numbers impact climate change and what role can curbing population growth play in meeting this challenge? With Jane O’Sullivan, Senior Research Associate, University of Queensland and Kathleen Mogelgaard, Senior Fellow at the Population Institute.


Episode 3. Population growth and the UN’s sustainable development goals

Creating a better world, with security and opportunity for all, cannot occur in the context of continued rapid population growth. With ten years left to achieve them, the international community must break its silence and tackle population growth if the United Nations’ SDGs are going to be realized. With Florence Blondel, Environmental and global justice campaigner and Olivia Nater, Senior campaigner, Population Matters.


Population concerns are often dismissed  because the rate of global population growth is decreasing. But is our current global population ecologically sustainable? The evidence suggests it may not be. With Karin Kuhlemann, population ethicist, University College London and João Abegão, PhD Candidate in Climate Change and Policies for Sustainable Development, University of Lisbon.


Episode 5. Solutions

Although many environmental trends are grim, there exist clear paths forward toward a more sustainable world – if we are willing to address human numbers. Solutions to curb population growth exist, grounded in respect for human rights and acceptance of demographic responsibilities. This inspiring message can rekindle hope in an environmental movement that desperately needs it. With William Ryerson, President, Population Media Center and Karen Hardee, Principle of Hardee Associates.


What impact does immigration policy have on greenhouse gas emissions, habitat preservation, sprawl, or water and air pollution? Join Leon Kolankiewicz and me, the authors of a recent environmental impact statement on US immigration policy, and find out. With Leon Kolankiewicz, science advisor at NumbersUSA.


Episode 7. Rewilding: new opportunities to share the landscape with other species

Declining human populations are often presented negatively in the press and by politicians. But they open up space for ecological restoration on the landscape. This episode discusses how fewer people can translate into more wild nature, and recent “rewilding” efforts in North and South America. With Tom Butler of the Northeastern Wilderness Conservancy, formerly with Tompkins Conservation.