A new study suggests a pretty positive century ahead for population growth on the West Coast, and cities like San Francisco that are less car dependent and already dense are likely to fare better as climate change factors give people more reasons to relocate.
After several years of doom-loop-and-gloom stories about San Francisco's sorry recovery from the pandemic, it may cheer you to know that some prognosticators see a brighter future for the city. Researchers at the University of Chicago believe that SF is poised to benefit from changing climate conditions in other parts of the country, as well as from the city's existing density, low reliance on cars, and transit infrastructure, as cities in the Northeast and Midwest see their populations decline.
The study, focused on long-range urban planning and published this month in the journal Nature Cities, comes from researchers in the University of Chicago's Department of Civil, Materials, and Environmental Engineering. It posits a wide range of factors that will influence population movement over the next 76 years (through 2100), the largest of which will be the impacts of climate change.
Cities more resilient to a changing climate, like San Francisco, with better educated, denser populations, are likely to be the winners over the next century. Other cities, meanwhile, may see their populations shrink as these populations shift, the researchers say.
It's a cautionary tale for planners in cities that could expect to see depopulation in the next several decades, with the goal of avoiding the mistakes of the past — i.e., the lack of planning for depopulation in urban centers that occurred in the wake of World War II.
Such "population loss in already developed cities can result in underutilized infrastructure with poor maintenance, possibly leading to disruptions in basic services like transit, clean water, electricity and internet access," the researchers write. "Having an estimation of future population trends can assist authorities in better planning and designing cities and their infrastructure systems for depopulation."
The study refers to two climate-change scenarios, one moderate and one more severe, that the researchers euphemistically refer to as "shared socioeconomic pathways."
"We inspect how these population trends vary regionally and how they vary across three city characteristics — degree of urbanization, income level and vehicle ownership — because housing location choice largely depends on income and accessibility," the researchers write.
The study finds that most states will experience population declines, generally, through 2100, and these declines will hit rural areas the hardest across the board. In-migration to cities will continue as it has in recent decades, and this will particularly benefit California's major cities as well as Portland and Seattle, and much of the American South.
Meanwhile, cities like Chicago, New York, and Boston will see either stagnant populations or declines, the researchers say.
A more extreme climate scenario puts San Francisco in more favorable territory, population-wise, than parts of California's southern coast.
This, of course, imagines a future when San Francisco has more abundant and affordable housing, but we'll just have to assume the best there.
In the maps below, you can see the two scenarios. SSP2 (a) is a moderate climate-change scenario with "intermediate challenges," and SSP4 (b) is "a road divided [where] adaptation challenges dominate."
The Chronicle made their own interactive versions of the maps based on the projectsions, which allow you to zoom in and drill down to the county level.
As you can see, both scenarios see parts of inland Northern California losing population, including the suburbs around Sacramento — which could certainly have to do with fire seasons getting worse!
As a whole, the study finds that "about half of the 30,000 US cities are likely to lose population by 2100." And, the authors write, "As depopulation is a multifaceted phenomenon that brings with it social, economic and environmental challenges, having half of the cities depopulating is consequential."
The problems associated with depopulation are many, and they include, "maintaining roadways in an adequate condition, offering travel alternatives for people who cannot drive, proving clean water, maintaining enough pressure in water distribution systems, maintaining sanitary and stormwater sewers, providing electricity safely and reliably, managing solid waste properly and providing affordable housing options."
The authors also examine how future immigration could impact their findings — and namely, they look at Long Island and areas around Chicago that have been magnets for immigration, and whose population losses may be mitigated by that immigration in the future.