NASA analysis shows unexpected sea level rise in 2024

LOS ANGELES -- Global sea levels rose faster than anticipated in 2024, primarily due to the expansion of ocean water as it warms, NASA reported Thursday.

A NASA-led analysis found that last year's rate of sea level rise was 0.59 centimeters per year, higher than the expected 0.43 centimeters per year.

"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," said Josh Willis, a sea level researcher at NASA's Jet Propulsion Laboratory in Southern California.

The unexpected increase was attributed to an unusual amount of ocean warming, combined with meltwater from land-based ice, such as glaciers, NASA explained.

In recent years, about two-thirds of sea level rise was driven by the addition of water from melting ice sheets and glaciers, with the remaining third attributed to thermal expansion of seawater. However, in 2024, these contributions were reversed, with two-thirds of the rise coming from thermal expansion, according to NASA.

"With 2024 as the warmest year on record, Earth's expanding oceans are following suit, reaching their highest levels in three decades," said Nadya Vinogradova Shiffer, head of physical oceanography programs and the Integrated Earth System Observatory at NASA Headquarters in Washington.

Since the satellite record of ocean height began in 1993, the rate of annual sea level rise has more than doubled. In total, global sea levels have risen by 10 centimeters since 1993, according to NASA.