Coastal populations expected to age significantly in the face of climate migration, researchers say

As climate change fuels sea level rise, young people will migrate inland, leaving aging coastal populations and numerous consequences in their wake, according to a study by Florida researchers State University.

As destination cities strive to sustainably accommodate growing populations, aging coastal communities will face significant new challenges, including an exodus of vital human infrastructure such as healthcare workers, said Matt Hauer, associate professor of sociology and lead author of the study.

The results are published in the journal Proceedings of the National Academy of Sciences.

“In destination communities where the population is growing, you will need more dentists, doctors, service workers, construction workers, etc.,” Hauer said. “So by moving people, you affect the likelihood that other people will move. You get population amplification.”

Previous studies have estimated where people are likely to move as climate change affects livability. Hauer’s study also incorporated demographic and spillover data that revealed a host of challenges awaiting both “origin” coastal communities and their destination counterparts.

“Imagine young families leaving areas like Miami and moving to other places and starting families there,” he said. “And just because more people have moved there, these indirect demographic processes attract even more people.”

The study concludes that these indirect processes could create 5.3 to 18 times more climate migrants than migrants directly displaced by rising seas. The study also found that by 2100, the median age in coastal communities could reach 10 years.

“Think about who is most likely to move and who will be left behind in these communities: It’s usually the oldest,” Hauer said. “As migration is more likely to occur in younger populations, areas experiencing accelerated outmigration could face accelerated aging of their populations.”

Doctoral student Sunshine Jacobs and computer scientist Scott Kulp co-authored the study with Hauer.

The researchers developed a migration model that uses sea level rise data from Climate Central and migration pattern information from the U.S. Internal Revenue Service. This tool allowed them to predict migration county by county across the country. Jacobs said the model can be adapted to look for different hazards beyond encroaching seas.

“We only observed sea level rise,” she explained. “Imagine other hazards that we know of cause people to move, like heat events, wildfires, and economic risks. The future uses and implications of the model are astonishing.”