These health-related dangers are certain to increase as rising sea levels coincide with the growing elderly population along the coasts, Dr. Hauer said.
In an analysis of all coastal counties in the United States, Dr. Hauer predicted that the proportion of people over 65 who lived in coastal communities would steadily rise, to about 37 percent of the population in 2100, compared with 16 percent today. That population would comprise older people moving in and younger people remaining into their later years.
“Two trends we know are happening — the impact of climate change at the same time the world is aging,” Dr. Hauer said. “Those two trends, I’m afraid, will crash head-on, and we will see more catastrophic impacts than if either one had happened.”
The Hoaglands said their stress was mounting as the climate risks on both coasts grew.
They moved to Florida in 1992 to raise their four children and practice medicine (Melissa, 64, as a pathologist and Guy, 65, as an internist). In 2011, they bought a house in the Bay Area, where Melissa had gone to medical school and had always dreamed of returning. They retired early, living in California in the summers and Florida in the winters.
Over the years, in Florida, hurricanes and storm surges up the Indian River threatened their home on a barrier island near Melbourne. During one storm, water jumped over a road within several feet of their house.
“Drainage was a problem on the roads,” Guy said. “I noticed the localized flooding was higher than it ever was.”
At the same time, wildfires, which were becoming more frequent, were spreading smoke in the Bay Area. An avid hiker, Guy began carrying an inhaler to help with exercise-induced asthma.