Coastal flooding in the United States is expected to worsen in the 2030s due to a combination of rising sea levels and an expected wobble in the moon’s orbit, according to a NASA study released Wednesday.
The agency’s Sea Level Change Science Team from the University of Hawaii made its predictions based on the moon’s typical 18.6-year orbit. During half of that orbit, high tides are lower than normal and low tides are higher than normal. During the other half, a wobble causes the tides to be more extreme – high tides are higher and low tides are lower.
The earth is currently in its amplified tide phase of the lunar cycle, but increased global warming and sea level rise is expected to worsen the tides during the next cycle.
“Low-lying areas near sea level are increasingly at risk and suffering due to the increased flooding, and it will only get worse,” NASA Administrator Bil Nelson said in a statement. “The combination of the moon’s gravitational pull, rising sea levels, and climate change will continue to exacerbate coastal flooding on our coastlines and across the world.
“NASA’s Sea Level Change Team is providing crucial information so that we can plan, protect, and prevent damage to the environment and people’s livelihoods affected by flooding.”
Phil Thompson, the study’s lead author and an assistant professor at the University of Hawaii, said high-tide floods aren’t as high as those caused by extreme weather events such as hurricanes.
“But if it floods 10 or 15 times a month, a business can’t keep operating with its parking lot under water. People lose their jobs because they can’t get to work. Seeping cesspools become a public health issue,” he said.
The study said the combination of the lunar wobble and rising sea levels will cause an increase in the number of floods on nearly all U.S. coastlines. Far northern coasts, such as those in Alaska, will be spared because the land there is rising due to geological processes.