Extreme sea levels will become a hundred times more common

A new study published in the journal Nature Climate Change modeled the occurrence of extreme sea levels (exceptionally high seas caused by a combination of tides, waves, and storm surges) in the coming decades. The results are bleak: due to rising temperatures caused by global warming, such extreme phenomena may become a hundred times more frequent by the end of the 21^st century.

An international team of scientists led by Claudia Tebaldi, a climate scientist at the Department of Energy’s Pacific Northwest National Laboratory, statistically analyzed the probability of extreme sea levels for 7,283 locations all over the globe. 

The experts estimated that the effects of rising seas will be felt most acutely in the Southern Hemisphere, the Mediterranean Sea, the Arabian Peninsula, the southern part of North America’s Pacific coast, the Caribbean, Hawaii, the Philippines, and Indonesia. Less affected regions will be those found at higher latitudes, such as the Pacific coast of Asia and the northern Pacific coast of North America.

The most worrisome aspect of this research is that even with a global temperature increase of only 1.5 to 2 degrees Celsius (compared to preindustrial temperatures), which scientists currently consider the best-case scenario for the following decades, these extreme phenomena will still occur with greater frequency, as the 2019 Intergovernmental Panel on Climate Change also reported.

“One of our central questions driving this study was this: How much warming will it take to make what has been known as a 100-year event an annual event? Our answer is, not much more than what has already been documented,” said Tebaldi. “It’s not huge news that sea level rise will be dramatic even at 1.5 degrees and will have substantial effects on extreme sea level frequencies and magnitude.”

More research is needed to clearly understand how these changes will affect local communities. The extreme sea levels will have different impacts at local scales, depending upon how vulnerable to rising waters specific places are, and how prepared are the local communities to cope with these changes.  

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By Andrei Ionescu, Earth.com Staff Writer