
TOP – Research and Outreach
Too many people consuming too much
William Rees is the originator of ecological footprint analysis, the influential approach to measuring sustainability. In a new article, he argues that humanity is deep into ecological overshoot and that we need to ratchet back our numbers and the size of our economies before nature does it for us. by Philip Cafaro William Rees has…
Earth continues to hemorrhage biodiversity, according to the latest Living Planet Report. Unfortunately, its authors cannot manage a clear statement of how to stop the bleeding. by The Overpopulation Project “You could think of it as a health check for the planet,” says the World Wildlife Fund, introducing its most recent biennial Living Planet Report,…
A recent letter in Biological Conservation criticized TOP researchers for writing about how more people means less space for wildlife. We responded that without limiting our numbers, people will not be able to protect the natural world. Who’s right? Please share your thoughts and ideas in the on-line comments below. by The Overpopulation Project This…
A recent letter in Biological Conservation criticizes TOP researchers for writing about how more people means less space for wildlife. We are curious what our readers think of the arguments and how you would respond. Please share your suggestions in the on-line comments below. by The Overpopulation Project This summer, TOP researchers published an article…
In June, the Great Transition Initiative ran a month-long forum under the title The Population Debate Revisited. The collection of contributed essays is now accessible on the GTI’s site, and makes for interesting reading. We thought three of the essays held particular merit and will republish them here over the next few weeks. The first…
The concept of human overpopulation, once common, is now rarely used in the scientific literature. Yet overpopulation is a major driver of biodiversity loss and a key obstacle to fairly sharing habitat and resources with other species. A new publication from TOP explores the connections between human numbers and preserving wild nature. by The Overpopulation…
Threats that humanity faces today are planetary in scale. That and their menacing character require long-term thinking and preventive politics to deal with or, better yet, prevent them. This may require planetary governance that unites humanity for mutual protection. by Jan Greguš, Masaryk University, Czech Republic Few would have believed five or ten years ago…
The concept of optimum population size is nothing new, but in recent decades the methodology used to calculate it has seen little development. In a recently published book, We Zijn Met Te Veel (Dutch for We Are Too Many), a new approach is proposed for calculating optimum population size. by Fons Jena In the available literature…
One of the biggest obstacles to addressing overpopulation is the ignorance and timidity of most environmental funders regarding population issues. So we were happy to recently come across the following text on the website of the Colcom Foundation, a major environmental foundation out of Pittsburgh, Pennsylvania, USA. Particularly welcome are the direct links they draw…
A recent book introduces a new approach to the science of overpopulation. We Zijn Met Te Veel (Dutch for We Are Too Many) explores a new theoretical foundation for the concept of overpopulation and explains why a smaller human population is a necessary – but not sufficient – condition for a more hospitable world. by…
8 Billion Angels is a rare full-length environmental film focused on population issues. Producer Terry Spahr joins Phil Cafaro for a discussion of the making of this fascinating film in an episode from season two of The Population Factor. by the Overpopulation Project 8 Billion Angels is both visually stunning and thought-provoking. If you haven’t…
The Population Factor, the show hosted by The Overpopulation Project’s own Phil Cafaro, returns with a second season, starting off with a discussion about the Nature Needs Half proposal. by The Overpopulation Project Wildlife populations are dwindling rapidly across much of the world and the number one cause is habitat loss, driven by excessive human…
In their curriculum, university students in biology and environmental sciences rarely learn how human population growth affects the environment, or discuss its role relative to other factors. Human activities are often dealt with in courses, but not population increase. One exception, described below, comes from a Swedish ecology class that learned about and discussed how…
A frequent assumption in population policy debates is that stabilizing populations will be sufficient to achieve ecological sustainability. But as Karin Kuhlemann observes, “that a population’s size is stable in no way entails sustainability. It may be sustainable, or it may be far too large.” A recent book from philosopher Trevor Hedberg convincingly argues the…
A new initiative aims to draw attention to stories about population and consumption from women around the world to mark World Population Day. The focus lies on personal experiences and encourages a greater discussion about the links between population, consumption, and protecting nature. By Pernilla Hansson World Population Day is held every year on the…
What impact does US immigration policy have on greenhouse gas emissions, habitat preservation, or water and air pollution? Episode six of The Population Factor on Earthx TV addresses these questions, while episode seven, the final episode of season one, discusses how declining human populations open up new opportunities for ecological restoration. by The Overpopulation Project…
by Larry D. Barnett The presence of too many people on planet Earth is a problem that generally receives just lip service. The lack of interest in the problem should not, however, be surprising. Hominids have been on Earth for millions of years,[1] and modern Homo sapiens has been around for millennia – by one…
The current pandemic has had many severe consequences, but it has also acted as a reminder of the need for international cooperation when facing global challenges. Continued environmental destruction will likely increase the risk for future pandemics. Population growth is one of the main driving factors of the continued encroachment into nature and needs to…
After decades of silence, the International Union for the Conservation of Nature has passed a motion reaffirming the importance of addressing population matters to achieving conservation success. This continues a welcome recent trend among conservation scientists to speak up about the potential benefits of reining in population growth. by Pernilla Hansson The International Union for…
Efforts to specify the optimal human population on Earth are as complex as they are controversial. A recent book from Cambridge University economist Sir Partha Dasgupta develops a theoretically rigorous approach to this perennial question, finding that an optimal human population might range from 500 million to 5 billion. by Philip Cafaro It is gratifying…
“Never let your sense of morals prevent you from doing what is right”I. Asimov In the outstanding film “A life on our planet”, Sir David Attenborough tells us which actions we need to implement to avoid a future catastrophe. His plan is feasible and affordable: we already have all the knowledge and technology required to…
The current economic system in Australia is a Ponzi scheme based on maintaining positive GDP through migration. Populations of native species are plummeting and people are faced with increased job insecurity and housing costs, all of which are side effects of the Australian government’s ongoing drive for an ever increasing population. by Kelvin Thomson In…
The latest biodiversity strategy from the EU Commission makes some good suggestions for increasing protection for Europe’s dwindling biodiversity. While new, ambitious targets for protected areas and ecological restoration are welcome, the document fails to point out the central role population size will play in whether they are achieved. Through allowing the EU’s human population…
With the ongoing tropical biodiversity crisis, protected areas play an important role for many species. But strict protection can harm local human communities that are reliant on the lands around them for survival. In addition, resources are often lacking to prevent illegal exploitation or hunting in strictly protected areas. Community-managed reserves have been suggested as…
Last year, TOP researchers published new policy-based population projections for the European Union. In a new companion piece, we explore the impacts of alternative immigration policies on two important EU environmental goals: reduction of greenhouse gas emissions and improved biodiversity conservation. We find that in both cases, less immigration, leading to smaller populations, will make…
By Jane O’Sullivan, Francesco Ricciardi, Susann Roth For sustainable development, universal wellbeing should be the goal, rather than endless growth. Minimizing further growth in human populations is only part of the solution, but an essential part. Climate change has been described as one of the greatest challenges of our time. But for many Asian countries,…
This past week, a widely reported article in Science found that since 1970, North American wild bird populations have declined by 30%. In response, conservation organizations banded together to advocate that concerned citizens keep their cats indoors, put tape on their windows, and drink “bird friendly coffee.” This—the massive and continuing decline of wild nature…
In a new review article published in the journal Environment, Development and Sustainability, Elias Ganivet reminds us that we need to address both excessive human consumption and population growth, to curb humanity’s environmental impact. Written from a very balanced perspective, Ganivet reviews the impacts of human population growth on global biodiversity and climate change, perceptions…
TOP assisting researcher, Patrícia Dérer, was recently interviewed for the Hungarian newspaper, 444. The article, shortened and translated to English, includes highlights from her interview where she discusses the conditional nature of population projections, the link between population and biodiversity, the declining population of eastern Europe, successful family planning programs, and much more. By Zsolt…
A new United Nations report on biodiversity was released this week with much media coverage. Scientists and mainstream journalists seem unwilling to address the fundamental drivers of biodiversity decline, but public response suggests transformative change is gaining traction. By Jenna Dodson This week, many media outlets are covering the pre-release of a new United Nations…
By Phil Cafaro Steve Irwin. Errol Flynn. The Sydney opera house. Kangaroos. Wombats. Here at TOP, we hardly need new reasons to love Australia. Yet last week, we came across two more: articles by Dr. Harry Recher and Dr. Freya Mathews that we somehow missed when they were first published several years ago. They do…
By Massimo Livi Bacci Four population-driven threats to space If from abstract principles and paradigms of my previous article (Malthus, forever?), we turn to the real, contemporary world, we may say that the rapidly expanding world population also has other consequences – beyond the reduction of “pristine” space – that may adversely affect the quality…
By Patrícia Dérer The primary cause of the global biodiversity crisis is human-induced alteration and loss of natural habitats1. One of the most important causes of habitat destruction is housing growth, manifested both in rural and urban sprawl. The impacts of housing growth derive from both building human dwellings and their associated infrastructure such as…
































