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(2024-01-11) Depopulation And Associated Challenges For US Cities By 2100

Uttara Sutradhar, Lauryn Spearing & Sybil Derrible: Depopulation and associated challenges for US cities by 2100. ...possibly leading to disruptions in basic services like transit, clean water, electricity and internet access. Simultaneously, increasing population trends in resource-intensive suburban and periurban cities will probably take away access to much needed resources in depopulating areas, further exacerbating their challenges. See also toots with screenshots of data.

This population decline in rural United States started long ago2 and is indicative of an economic shift, which ultimately reduces community well-being and the possibility of a sustainable future3. Young adults often migrate out of rural business centers, altering the demographic composition and leaving an aging population in depopulating areas. Nevertheless, rural areas are not alone

In this Article we use organically emerging population agglomerations defined as ‘places’ by the US Census Bureau10, hereafter simply referred to as ‘cities’.

Results

Current trends in cities

Major metropolitan centers like Detroit (MI), Cleveland (OH) and St Louis (MO) are experiencing moderate to slow depopulation, while some of the suburban and periurban cities located outside of these centers show an increasing trend

Population density in cities with a highly increasing population is low compared to slowly or moderately increasing cities, which suggests that these cities may be new or have more recently started to attract many people. Or they just add sprawl? Or does that get counted in peri urban cities?

Future trends in cities

To estimate future trends, two projected datasets were used to find trends for the 31,568 cities included in the Census Bureau’s 2020 TIGER/Line Shapefiles. Both projections consider five scenarios called shared socioeconomic pathways (SSPs) that range from environmentally friendly development (green road) to fossil-fueled development (highway), defined in terms of socioeconomic developments in response to the impacts of climate change. The two datasets are

  • Global 1-km Downscaled Population Base Year and Projection Grids Based on the SSPs, v1.01 (2000–2100), referred to as ‘NCAR data’ hereon
  • US County-Level Population Projections, Total and by Sex, Race and Age, based on the SSPs, v1 (2020–2100), referred to as ‘Hauer’s data’ hereon (Matt Hauer)

Figure 2 shows the future population trends for SSP2 (middle of the road—intermediate challenges) and SSP4 (a road divided—adaptation challenges dominate), highlighting the variation in population trends from the two scenarios

Next, we focus on three city characteristics—degree of urbanization, income level and vehicle ownership—and inspect their relationships with future population trends.

Variation based on degree of urbanization

For degree of urbanization, we categorize the cities into four classes—urban, suburban, periurban and rural—based on location, housing density, population and commute time.

We examine the proportion of cities along with their future trends in the four US regions. Figure 3 shows the results for scenario SSP2

population density, we find that cities with a higher population density are more likely to gain population (Supplementary Fig. 4).

Policies to combat challenges stemming from population decline need to be localized given that each city may have unique needs.

Population trends and median income

In the Northeast and Midwest, urban cities with lower median household income are more likely to experience depopulation over time

population decline can create affordability concerns with infrastructure services, such as water and electricity, due to a dwindling tax base, and operations, management and maintenance (OMM) challenges

Across all regions, however, high-income cities in suburban, periurban and rural areas are likely to experience an increase in population, which is concerning from an environmental sustainability viewpoint if current suburban and periurban forms of planning (for example, urban sprawl) persist, as resource allocation and energy consumption tends to be higher in areas with a low population density.

Population trends and vehicle ownership

Fig. 5 shows that, in the Northeast region, urban cities with low vehicle ownership (defined as percent population with one or fewer vehicles per household) as well as some suburban and periurban cities with low vehicle ownership are likely to experience population growth. These suburban or periurban cities may be located close to urban centers, thereby having better accessibility

Only a few urban cities have low car dependency (automobile), which is plausible considering the low availability of transit services in US cities. Car dependency at such scales will require interventions from authorities to support aging communities in cities that are likely to depopulate by 2100.

Impact of immigration

suggests that cities like Long Island (NY) and those around Chicago (IL), which are experiencing population loss, may still grow thanks to immigration.

Asian and Hispanic immigrants are settling in smaller cities at the periphery of major cities. Settling close to a major city provides employment and accessibility opportunities, which can be a reason for higher immigrant settlements in these peripheral cities.

Discussion

The findings of this Article indicate that the number of depopulating cities in the Northeast and Midwest will be higher than in the South and West regions (although many cities in the North and Midwest will still grow). It smells like the analysis ignores effects of climate change in making some places unlivable. But maybe I missed it....

Conclusion

Limitations

Methods

Current trend identification and labeling

Data processing for future trend forecasting

Weighting the datasets

Estimating the impact of international immigration

Classifying cities in an urban–rural continuum to define the degree of urbanization

Joining core-based statistical area and urbanized areas

Data availability

A copy of the final output dataset with future population trends for different SSP scenarios is provided in the code repository in csv format. https://github.com/usutradhar/Population-Trend-Analysis https://github.com/usutradhar/Population-Trend-Analysis/blob/main/df_attributes.csv

  • fields: STATEFP GEOID NAMELSAD weighted_HU_density_sqmi label density_km2 CensusPop_20 future trend from SSP 1 future trend from SSP 2 future trend from SSP 3 future trend from SSP 4 future trend from SSP 5 REGION DIVISION tt_2_work_place no_veh veh_1 veh_2_or+ GEOID_place GEOID_cbsa cbsa20-to-place allocation factor tt_2_work GEOID_ Urban area (2022)count population_place_sum ua-to-place allocation factor_min ua-to-place allocation factor_max population_ua_min population_ua_max city type median_income veh 1+ veh<=_1
  • doesn't give you zip or even state clearly! Uses FIPS code for STATEFP column (01=Alabama)
  • "place" (city) ID = geoid
  • I sorted the spreadsheet by population (CensusPop_20) (city size): interestingly, their urbanization grouping ("city type" for a number of those top cities is "suburban", presumably based heavily on population density

Code availability (jupyter notebooks)

Thousands of U.S. Cities Could Become Virtual Ghost Towns by 2100. The Urban U.S. could look very different in the year 2100, in part because thousands of cities might be rendered virtual ghost towns. According to findings published in Nature Cities, the populations of some 15,000 cities around the country could dwindle to mere fractions of what they are now. The losses are projected to affect cities everywhere in the U.S. except Hawaii and Washington, D.C.

Derrible and his colleagues were originally commissioned by the Illinois Department of Transportation to conduct an analysis of how Illinois’s cities are projected to change over time

identify current population trends in more than 24,000 cities and to model projections of future trends for nearly 32,000.

They applied the projected trends to a commonly used set of five possible future climate scenarios called the Shared Socioeconomic Pathways. These scenarios model how demographics, society and economics could change by 2100, depending on how much global warming the world experiences.

The authors’ resulting projections indicated that around half of cities in the U.S., including Cleveland, Ohio, Buffalo, N.Y., and Pittsburgh, Pa., are likely to experience depopulation of 12 to 23 percent by 2100. Some of those cities, including Louisville, Ky., New Haven, Conn., and Syracuse, N.Y., are not currently showing declines but are likely to in the future, according to the findings

Regionally, the Northeast and Midwest will most likely be the most heavily affected by depopulation, the authors found. And on a state level, Vermont and West Virginia will be the hardest hit, with more than 80 percent of cities in each of these two states shrinking. Illinois, Mississippi, Kansas, New Hampshire and Michigan could also see about three quarters of their cities decline in population.

the places that are projected to most likely gain population by 2100 tend to be located in the South or West.

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