The Overpopulation Project

Over the past two centuries Earth’s human population has doubled, and doubled again, and nearly doubled yet again, increasing from 1 billion to 7.8 billion people. This huge increase is at the root of grave global environmental problems, from climate change to mass species extinction. Yet in recent years, discussing population issues has become taboo among many environmentalists and policymakers. The Overpopulation Project aims to end the silence, by researching the environmental impacts of overpopulation, exploring humane policies to end population growth around the world, and fostering public and scholarly discussion of these issues.



With help from a generous grant from the Global Challenges Foundation, for the past two years my colleagues Frank Götmark, Jenna Dodson, Patrícia Dérer and I have examined the environmental impacts of overpopulation and reported on best practices for ending population growth around the world. Recently we unveiled new animated policy-based population projections for the European Union, a great new tool for European citizens to understand their demographic choices facing their societies.

Here are our scholarly publications from the past two years:

"Policy-based Population Projections for the European Union: A Complementary Approach.” P. Cafaro and P. Dérer. Comparative Population Studies 44 (2019): 171-200.

“The Potential Environmental Impacts of EU Immigration Policy: Future Population Numbers, Greenhouse Gas Emissions and Biodiversity Preservation.” P. Cafaro and F. Götmark. Journal of Population and Sustainability 4 (2019): 71-101.

“How Should Ecological Citizens Think About Immigration?” P. Cafaro and J. O’Sullivan. Ecological Citizen 3 (2019): 85-92.

“Aging Human Populations: Good for Us, Good for the Earth.” F. Götmark, P. Cafaro and J. O’Sullivan. Trends in Ecology and Evolution 33 (2018): 851-862.


And here are some of our most popular recent blog posts:


* Empty skies, empty words. September 24, 2019







The Global Challenges Foundation was founded in 2012 by Swedish financial analyst and author Laszlo Szombatfalvy. The Foundation’s aim is to contribute to reducing the main global problems and risks that threaten humanity, particularly climate change, degradation of global ecological systems, politically motivated violence, extreme poverty and population growth. We appreciate their support!