High-tide flooding is a phenomenon quite often experienced by the inhabitants of many cities on the US Atlantic and Gulf coasts. Also known as nuisance floods or sunny day floods, high-tide floods are likely to increase in the US by mid-2030s, partially due to a “wobble” in lunar orbit.
A NASA-led study, published in the journal Nature Climate Change, said that the planet’s lunar cycle would exacerbate climate change-induced sea level rise in coming years. The study also indicated that every US coast will witness rapidly increasing high-tide floods, when the lunar cycle will amplify rising sea levels.
The National Oceanic and Atmospheric Administration (NOAA) reported a total of over 600 such floods in 2019. It is likely to get worse as with the beginning of next decade, the alignment of sea level rise with a lunar cycle will cause coastal cities all around the US, causing dramatic increase in flooding.
The study was led by the members of the NASA Sea Level Change Science Team from the University of Hawaii, concluding that high tides will exceed known flooding thresholds around the nation that may leave city dwellers to deal with floods every day or two.
NASA Administrator Bill Nelson said,
Low-lying areas near sea level are increasingly at risk and suffering due to the increased flooding, and it will only get worse. 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.
Phil Thompson, an assistant professor at the University of Hawaii and the lead author of the study, said that if flooding occurred 10 or 15 times a month, people will lose their lives and livelihoods. It will also create a public health issue.
High-tide floods are likely to increase in the US by mid-2030s, partially due to a “wobble” in lunar orbit | Image: Hawaii Sea Grant King Tides Project
Furthermore, cities on these widely separated coastlines will begin to experience higher rates of flooding at almost the same time. The main factor to which is that a regular wobble in the moon’s orbit take 18.6 years to complete.
Although, there is nothing new or dangerous about the lunar orbit wobble, climate change-caused sea level rise could wreak havoc across the planet.
Almost all US mainland coastlines, Hawaii, and Guam are expected to experience exacerbated floods. Only far northern coastlines, including Alaska’s, will be safe for another decade or so as these land masses have been rising due to long-term geological processes.