Sea level rise is a well-covered topic when it comes to the symptoms of climate change. Scientists have been observing it for decades and using it as a marker of how drastically our planet changes over extended periods of time, but still, the phenomenon is finding ways to surprise them. That’s one takeaway from a NASA analysis, which found that sea level rise in 2024 was not only greater than expected but it was also fueled by an unexpected factor.
For starters, the expected rate of rise was 0.17 inches (0.43 centimeters) per year. The actual rate of rise was 0.23 inches (0.59 centimeters) in 2024. While that number may not seem incredible, when expanded over several years and even decades those numbers become more and more significant.
“The rise we saw in 2024 was higher than we expected,” said Josh Willis, a sea level researcher at NASA’s Jet Propulsion Laboratory in Southern California. “Every year is a little bit different, but what’s clear is that the ocean continues to rise, and the rate of rise is getting faster and faster.”
As mentioned, what drove sea level rise in 2024 was also unexpected.
It’s common knowledge that our warming planet causes glaciers to melt, adding more water to the ocean. In recent years, says NASA, about two thirds of the water added to the ocean came from land, and the other third has come from thermal expansion. This happens when water volume increases because of heat. NASA says the ratio flipped in 2024, with about two-thirds of sea level rise coming from thermal expansion and the other third coming from melting ice. Temperatures are increasing, no matter how it’s sliced.
“With 2024 as the warmest year on record, Earth’s expanding oceans are following suit, reaching their highest levels in three decades,” Nadya Vinogradova Shiffer, head of physical oceanography programs and the Integrated Earth System Observatory at NASA Headquarters in Washington said in a statement.
With sea level at U.S. coastlines expected to rise on average between 10 to 12 inches in the next 30 years, our waves, our coastal communities, and coastal ecosystems, will look (and be) very different a few decades from now.
“Surfers know that many waves are very tide sensitive,” Dr. Chad Nelsen, CEO of the Surfrider Foundation, told The Inertia this week. “Sea level rise is rapidly accelerating and is going to cause permanent high tide, which is going to flood many waves, reducing their quality or existence.”
