Resource Science: The US population numbers and immigration

Environmental issues are frequently described in excellent WLJ articles by Anna Miller Fortozo and Charles Wallace. Their in-depth writing is remarkable, covering diverse topics like property rights, corner jumping, the cost of land, environmental regulations, grazing leases, expansion of bison, and wolves and bears killing livestock.

A common factor in environmental conflicts is land use. For example, environmental groups try to dictate land use with endangered species and wetland regulations. Farmers, ranchers, loggers, miners and oilmen use the land to make a living and provide resources for the country.

I think conflicts over land use are increasing and are to some extent the result of the increasing numbers of people in the West, many who do not work in agriculture and natural resources. We often focus on the individual issues, like seeing the trees, but we may not appreciate underlying causes of conflict, like seeing the entire forest. I think the forest view shows that an increasing population contributes to environmental land use conflicts.

The well-known biologist Paul Ehrlich died in March 2026. His influential book, “The Population Bomb,” published in 1968 describes how worldwide population growth can result in famines, resource shortages and other disasters. The book has been criticized for being alarmist with unrealized predictions and recommending government regulation of populations, but the basic premise that increasing numbers of people increases impacts is valid.

Consider India (1.43 billion people) and China (1.41 billion people). Population growth in the western U.S. is not as severe as in China and India, but the recent migration of many people to the west, in places like the Front Range in Colorado and Bozeman, MT, where I live, results in increased traffic, development of crop land, pasture and wildlife habitat for housing, and greatly increased hunting and recreation on public lands.

Although the U.S. population is increasing (see the graph) fertility rates in the U.S. have declined to 1.62 births per woman. This has been noted by the Trump administration as a reason for encouraging more births by American women. Birth rates are useful, but I think it’s important to also consider the actual numbers in the population. In this article I’ll provide data on the U.S. population numbers as in previous articles (see the References below) for two time periods, September 2025 to July 2026 (the 2026 time period) and June 2025 to September 2025 (the 2025 time period).

The U.S. population has been growing at a steady rate from 1900 to 2026 as shown in the graph. The U.S. Census Bureau reports the U.S. population was 342,658,948 on July 13, 2026, with one birth every 8 seconds, one death every 11 seconds, one international migrant every 100 seconds, and a net gain of one person every 28 seconds. There was an increase of 190,886 people in the 10 months of the 2026 time period which is 19,089/month. The previous increase in the three months of the 2025 time period was 154,835/month. That’s a decrease of 135,746 per month between September 2025 and July 2026. Something happened to cause this decrease.

The components of population growth suggest what happened. The birth rate in the 2025 and 2026 time periods was the same, 1 birth/8 seconds (10,800/day). The death rate in the 2025 and 2026 time periods was the same, 1 death/11 seconds (7,854/day). International migrants were less in the 2026 time period, with 1 migrant/100 seconds (864/day) than in the 2025 time period with 1 migrant/22 seconds (3,927/day). The number of migrants in July 2026 was 22% of that in September 2025.

While births and deaths stayed the same, migration decreased from September 2025 to July 2026. This is apparently the cause of the smaller net increase in population in the 2026 time period with 1 person/28 seconds (3,086/day) compared to the 2025 time period with 1 person/14 seconds (6,171/day). The net increase in population in the 2026 time period was half of the 2025 time period, apparently because of fewer migrants. This might be due to the Trump Administration’s border and immigration policies. The Census Bureau data doesn’t differentiate legal and illegal immigrants so it’s not possible to say if this is the case for sure.

The positive and negative aspects of population growth, and immigration’s effect on it, are complicated. Population growth can be positive for the economy, but negative regarding environmental and social impacts. The numbers presented above show that reducing immigration reduces the rate of population increase. This is perhaps obvious, but having numbers gives credibility for discussions on this important issue. Government can try to influence the population with policies such as tax credits for children and encouraging larger families. But as I’ve noted before (see the References), in a free country, immigration is the one population factor that the government can directly control to influence population numbers. — Matt Cronin, WLJ columnist

(Matt Cronin is a biologist with Northwest Biology and Forestry Company LLC in Bozeman, MT, and a teaching professor at Montana State University. He may be contacted at croninm@aol.com.)

References

Ehrlich, Paul R. (1968). The Population Bomb. Ballantine Books.