In his Nobel Prize acceptance speech, Norman Borlaug, the agronomist who developed a more productive and sturdier wheat warned us that he had only given us a pause in the ongoing race between incessant human population growth and our capacity to produce more food. Recently, more than a hundred Nobel Prize laureates signed a similar warning: “we are not on track to meet future food needs, not even close.”
In her essay in the June 20, 2025, New Yorker, Elizabeth Kolbert comments on Borlaug’s work and his warning and reviews two new books on this theme.
In his book on “We Are Eating the Earth: The Race to Fix Our Food System and Save Our Climate” (Simon and Schuster), journalist Michael Grunwald investigates agricultural practices and technical processes that are intended to produce food without negative side effects. He finds that these projects fail to produce more food and often lead to greater environmental damage. For example, it takes a lot of light bulbs to replace the sun.
Vaclav Smil, in “How to Feed the World: The History and Future of Food” (Viking), works with statistics. For example, he reports on the impossible technical capacities that would be required to grow even one percent of the world’s current meat consumption and repeats the warning about trying to duplicate photosynthesis. Although the photosynthesis upon which our food supplies depends may be inefficient , it is so complex and fragile a system it is unlikely to be duplicated by humans.
Smil does point out that the world (and particularly the people of the United States) waste a huge amount of food. Not enough to save mankind but surely something to be ashamed of.
Most, if not all, of the earth’s environmental problems are a result of human activity.
Some scholars have represented the problem with the formula I = P+A+T. I = Impact (on environmental) P = Population (size) A = Affluence (wealth) T = Technology
The validity of expressing environmental impact as a sum of independent factors has been the subject of debate among environmentalists. I = PAT is not, after all, a mathematical equation. It is only a graphic representation of the problem. One criticism draws attention to the difficulty of expressing the inter-relationships among the three factors, another suggests that there are other important factors not included in the formula, such as political and social structures.
The Dependent Variable: Impact
The variable “I” in the “I=PAT” equation represents environmental impact. The environment may be viewed as a self-regenerating system that can endure a certain level of impact. The maximum endurable impact is called the carrying capacity. As long as “I” is less than the carrying capacity the associated population, affluence, and technology that make up “I” can be perpetually endured. If “I” exceeds the carrying capacity, then the system is said to be in overshoot. Overshoot may degrade the ability of the environment to endure impact, therefore reducing the carrying capacity.
Simply put, each I=PAT factor affects environmental quality as a result of the combination of each factor’s effect on the carrying capacity (the ability of a particular region or biome to support a particular population with basic survival resources/needs as well as the ability to sustainably absorb the resulting waste and pollution). A stable carrying capacity results in a sustainable and healthy quality of life for all resident species.
Population (size)
The larger the population (global humans currently at 8 billion+), the more stress and negative impact it has on the carrying capacities of both the occupied and fringe environments. This resulting decrease in the local carrying capacity results in population overcrowding, over resource consumption and pollution with its resulting negative effects on the environment and decreased quality of life for all.
Environmental impacts of population
Increased population increases humans’ environmental impact in many ways, which include but are not limited to:
• Increased Land Use – Results in habitat loss for other species
• Increased Resources Use – Results in habitat loss of other species
• Increased Pollution – Can cause sickness and damages ecosystems
• Increased climate change
• Increased biodiversity loss
Affluence (wealth)
The variable A in the I=PAT equation stands for affluence. It represents the average consumption of each person in the population. As the consumption of each person increases, the total environmental impact increases as well. High resource consumption with high resulting waste and pollution is not sustainable, healthy or otherwise conducive to a reasonable quality of life for all.
Technology (resource intensity)
The T variable in the I=PAT equation represents how resource intensive the production of affluence is; how much environmental impact is involved in creating, transporting and disposing of the goods, services and amenities used. Improvements in efficiency can reduce resource intensiveness which reduces the T multiplier.
However, increases in efficiency from technologies such as renewable energy can reduce specific environmental impacts, but due to increasing prosperity these technologies yield for the people and businesses that adopt them, technologies actually end up generating greater overall growth into the resources that sustain us.
Impact (of combined factors)
In summary, each factor increase within I=PAT combines and compounds to increase the negative impacts on the carrying capacity of the earth’s environment. Sadly, each of these factors continues to increase with the predominant societal, economic and political attitude of pro-growth at all costs, including the continued infinite consumption of the finite natural world.
Edward Abbey, environmental author and activist said: “Growth for the sake of growth is the ideology of the cancer cell”.
SUGGESTED SOLUTIONS TO REDUCE IMPACT (I)
Population (size)
• Lower fertility rates / smaller families • Women’s empowerment and girls’ education • Access to family planning and contraception for all Note: more of the above results in less need for abortions.
Affluence (wealth)
• Sustainable spending on basic needs and less on luxury materialism • More activities, leisure and cultural
Technology/Economics
• Less consumption with less energy requirements (renewable and non-renewable) • Economic steady state sustainability. Refer to the Center for A Steady State Economy (CASSE) steadystate.org
Attitudes/Culture:
• A cultural and spiritual paradigm shift in environmental and economic attitudes • Respect for the earth, each other and all sentient beings • Economic de-growth • Environmental pro-growth • Balance
In Summary the I=PAT equation can be a useful way of thinking about and then addressing the global, national and local environmental concerns.
The Population Connection recently conducted a survey regarding family size. The results from the survey are summarized in the article titled: Americans Want Small Families, Aren’t Concerned About Declining Birth Rates. Population Connection. Written by Olivia Nater, Communications Manager | Published: June 16, 2025. Website is: Americans Want Small Families, Aren’t Concerned About Declining Birth Rates
The following provides introductory comments for the survey. These comments are very relevant in relationship to Utah’s lower fertility rates.
An extensive new survey by Population Connection reveals that Americans have an established preference for small family sizes and do not perceive low fertility rates as a problem. Our survey also sheds light on the factors that influence the childbearing decisions of younger Americans — the top impacts being concern over the state of the world and affordability.
The context
The population narrative in today’s media stories revolves predominantly around low fertility rates in high-income countries, with many outlets describing this as a problem or “crisis.” This narrative is grounded in concern that population aging and decline could negatively impact economies, and ignores the countless benefits of reduced population pressure. It also fails to acknowledge the fact that our global population is still growing, and that even many high-income countries with low birth rates are still becoming more populous due to a combination of demographic momentum and immigration.
Falling Fertility rates in Utah, but Increasing Population
When the Utah Population and Environment Council (UPEC) began in 1997 the fertility rate for women in Utah was approximately 2.6. (This was the highest fertility rate in the nation.) The fertility rate declined below the replacement level to 1.85 in 2022 (Utah’s Declining Fertility Rate, 2022.) Replacement level is considered 2.1 and means that if the fertility rate is at about 2.1, then the total Utah population would remain similar and at a point in time would not continue to grow if the only factor is fertility rate in the state and not in-migration.
This decline in fertility rate is considered a very positive trend by UPEC.
“Utah’s population growth slowed slightly in 2024, but the Beehive State still added 50,392 more residents last year, with much of the growth in Utah and Salt Lake counties. Natural growth — the balancing of births to deaths — and migration were about equally responsible for the population increase.”
Increases in National and International populations
The United States population was 281 million in 2000, is estimated at 344 million in 2025 and projected at 371 million in 2050. This is an increase of 63 million from 2000 to 2025 and a projected increase of 27 million from 2025 to 2050.
The world population was 6.1 billion in 2000, is estimated at 8.2 billion in 2025 and projected to reach 9.8 billion in 2050. This is an increase of 2.1 billion from 2000 to 2025 and 1.6 billion from 2025 to 2050.
For both the United States and the world, the increase in population is greater from 2000 to 2025 than is projected from 2025 to 2050, but these are still significant projected increases. While the United States and world population is expected to grow significantly there are many countries that are expected to decrease in population. This is a concern for many countries and there is often talk about the need to increase human population, especially in some countries, even though the world population is projected to continue growing.past, present and projected.
UPEC has an updated website. YAY! A big thanks and shout-out to XMission for hosting our website for free. Please check out the refreshed site and the beautiful images of Utah that grace the home page HERE. If you have comments on the site, please share with us: info@utahpopulation.org
Second Drum Roll…
The Board of UPEC recently decided to revive our Small Families Campaign for the next few years. We want to be a logical and compassionate counterweight to “the sky is falling” alarms about a declining birthrate. We will keep you updated here as this campaign takes shape.
Creating Change
I have been thinking a lot about power over vs. power with, really listening to each other, and what I might do to have a positive impact in these turbulent times. Below are some of the musings that have been tumbling around in my head.
Power with: None of us like being told what to do. From toddlers to our great grandparents, we all like options, having autonomy, and making our own decisions. That is how lasing change is made.
Deep Listening: When we actively listen to the person in front of us, for what they really care about, we often find we have much in common. We can get more done when starting from a place of shared values. And truly listening is key.
How might I have more impact: Keep it local is my newest mantra. I cannot change tariff wars or federal policies. But I can work with local groups to create change in my neighborhood and community.
I share all of this because it relates to the choices we make regarding having children or not; and if so, how many? How might we really listen to those who make different family choices? Do young people feel like they even have options and autonomy right now? Am I doing enough in my community to support others? Where might I do more?
Solutions in tidy packages with shiny bows do not exit. Collaboration is messy. Deeply listening is challenging. Engaging in my local community takes time, effort, and energy.
My wish is that all of us, you and me, find more ways to be challenged and engaged in causes that make lasting change!
Stephanie Feldstein, Population and Sustainability Director, Center for Biological Diversity provided a well-informed presentation on “Biodiversity and Human Population” as part of the Utah Population and Environment Council, 2024 Speakers Series on May 6, 2024.
Stephanie leads the Center’s work to highlight and address threats to endangered species and wild places from runaway human population growth and overconsumption. Previously Stephanie worked for Change.org, where she helped hundreds of people start and win online campaigns to protect wildlife. She holds a bachelor’s degree from the University of Michigan. She is the author of The Animal Lover’s Guide to Changing the World (St. Martin’s Griffin, 2018).
Stephanie described the increase in human population over time. She also portrayed the growth in consumption. These are the “hockey sticks” that show such dramatic escalations in population and consumption over the last 1,000 years or so.
Stephanie talked about the impacts of increased human population and consumption on wildlife populations. Two examples provided were the decrease in bumble bees due in part to the increase in honeybees, which can be considered livestock. Another example is the estimated 10,000 grizzly bears that were in California, while now there are none.
Bringing this closer to Utah, 12 of the 15 fastest growing cities in the United States are in the west. And 40 million people now live in the Colorado River Basin.
The human population is expected to grow in the Salt Lake area and there is a projection of over 6 million people that could be living in Utah in the future. About three-quarters of Utahns live in the Great Salt Lake watershed, which has numerous concerns including increased agriculture and toxic chemicals. These increased concerns have helped result in petitioning the United States Fish and Wildlife Service (USFWS) to list the Wilson’s Phalarope as an Endangered species.
Some ways to address this population concern are to help support reproductive freedom. Still an estimated nearly half of the population comes from unplanned pregnancies. Also, more could be done to help educate people about the impacts of increasing population, including impacts on wildlife.
Three-quarters of Utah’s population lives around Great Salt Lake, one of the fastest-growing areas of the country. It’s also an oasis for more than 10 million migratory birds passing through every year.
Although Utah is one of the least densely populated states in the U.S., more than 2 million people are crowded along the Wasatch Front. The Great Salt Lake provides a stark example of the impact of human population pressure and how protecting imperiled species can protect our future, too.
