LOS ANGELES (CNS) — Low birth rates, uncertainty over immigration and long-term impacts from COVID-19 will result in a year-over-year population decline in Southern California for the first time ever, researchers said in the first of a two-part demographic conference sponsored by the Southern California Association of Governments and USC.

The 32nd annual Demographic Workshop, held virtually this year, is built around the theme, "The Post-Pandemic City." Participants are taking a close look at several intersecting developments that could significantly change life in the six-county SCAG region, including the pandemic and post-pandemic recovery, heightened awareness of racial equity and inclusion, and results of the 2020 Census. The latter already will result in California losing a Congressional seat.

Part two of the workshop will be held next June 15.

For decades, Southern California has ranked among the most vibrant population centers in the United States, climbing above 19 million. However, the rate of growth has slowed throughout the 2010s as declining fertility rates, the housing crisis and other factors have resulted in a gradually aging — and less mobile — population base.

According to projections released Tuesday, the fastest-growing segment of the population will be mature retirees, ages 75-84, followed by young retirees (65-74) and seniors (85 and older). Meanwhile, there will actually be a decline in college-age young adults and preschool-age children. Also, the ratio of working-age adults to retirement-age adults — which once stood at six to one — has fallen below four to one, according to the workshop projections.

Compounding all of this is the pandemic, which led to an increase in mortality rates, a further decrease in birth rates and virtually halted foreign immigration into California. As a result, 2020 saw the first year-over-year drop in overall population.

"We're facing a lot of unknowns as we emerge from the pandemic," said Clint Lorimore, president of SCAG and an Eastvale City Council member. "However, with uncertainty, there is opportunity in front of us. We need to position ourselves to plan for the future. It's a great privilege for SCAG to be able to bring together the best minds across the region and the state so that we can help cities meet their needs and work toward a better future for their residents."

SCAG is the nation's largest metropolitan planning organization, representing 6 counties, 191 cities and more than 19 million residents.