A NASA study warns that high-tide flooding, or nuisance flooding, as they are also called, could become prevalent on America’s coasts in the coming decades.
Nuisance floods are those that occur when the tides reach just over half a meter (0.6 m) above the daily average high tide. What happens is that streets, houses are flooded, water can seep through storm drains and cesspools can overflow. They are not dangerous, but they do cause damage if they last over time. In 2019 in the United States there were more than 600 floods of this type , according to data from the National Oceanic and Atmospheric Administration (NOAA). The current NASA study published recently in the journal Nature Climate Change predicts an increase of two to three times that number.
According to the results, this increase would begin around 2030. It would be linked to various factors such as sea level rise or climate change . The latter is heating the Earth’s atmosphere, which causes the glacial ice to be melting in record time, dumping huge amounts of meltwater into the ocean. According to data provided by NOAA, mean sea level has risen between 21 and 24 centimeters since 1880, and a third of that rise has occurred in the last 25 years. By 2100, sea level could rise 0.3 m to 2.5 m above its level in 2000, depending on the extent to which humans limit greenhouse gas emissions in the next few years. decades.
The rise in sea level will receive a “help” from the Moon when it comes to producing floods. It is well known that the Moon influences the tides, but the force of its attraction is not the same every year. In its orbit there is an oscillation or wobble that slightly alters its position with respect to planet Earth in a rhythmic cycle of 18.6 years. When the Moon is mid-cycle, the moon suppresses the tides on Earth. This results in lower high tides and higher low tides. In the other half of the cycle, the tides are amplified, the high tides are higher and the lows are lower.
We are currently in the middle of the cycle where high tides are highest. The next cycle of amplification will begin in the mid-2030s . By that date, the study authors point out that global sea level will have risen enough to make those higher-than-normal tides especially problematic .
To the rise in sea level and what will happen during the lunar cycle, we must add atmospheric phenomena such as El Niño, which will cause floods to occur at certain times of the year. It will not be uncommon, therefore, to see months of incessant coastal flooding.
“This initially regional problem should quickly become national, affecting all American coasts,” the study authors say in Live Science . “If 10 to 15 floods occur each month, companies with underground parking lots will no longer be able to function,” Phil Thompson, assistant professor at the University of Hawaii, told the same outlet. “If people lose their jobs, this issue will become a national issue,” Thompson said.
The study authors recommend that measures be put in place to limit the harmful effects of these floods.
