Sea Level Rose At 0.59 Cm/Year Rate In 2024, And NASA Says It Was Faster Than Expected

In 2024, global sea levels rose faster than predicted due to thermal expansion from warmer ocean temperatures, with an increase of 0.23 inches per year, exceeding the previous estimate of 0.17 inches.

The increase in ocean height is linked to the way heat moves through seawater.

Source : NASA

Climate News: Global sea levels rose faster than predicted in 2024, with NASA reporting a rate of 0.23 inches (0.59 cm) per year, compared to the expected 0.17 inches (0.43 cm) per year. The primary cause was found to be thermal expansion, as warmer ocean temperatures caused water to expand, making up two-thirds of the rise — a reversal of previous years when melting ice sheets contributed more.

“The rise we saw in 2024 was higher than we expected,” a NASA article quoted Josh Willis, a sea level researcher at NASA’s Jet Propulsion Laboratory, as saying. “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.”

Rising Temperatures And Ocean Expansion

The past year was the warmest on record, leading to higher ocean temperatures and record-high sea levels in the past three decades, according to the NASA-led analysis.

“With 2024 as the warmest year on record, Earth’s expanding oceans are following suit, reaching their highest levels in three decades,” according to Nadya Vinogradova Shiffer, head of physical oceanography programs at NASA Headquarters.

Since 1993, when satellite records began, the annual rate of sea level rise has more than doubled, with a total increase of 4 inches (10 cm) over that period. NASA tracks ocean height using satellites, starting with TOPEX/Poseidon in 1992and continuing with the Sentinel-6 Michael Freilich satellite, launched in 2020. Its twin, Sentinel-6B, will soon extend these measurements, covering 90% of the world’s oceans.

How Heat Moves Through The Ocean

The increase in ocean height is linked to the way heat moves through seawater. Normally, warm water stays near the surface, while cooler, denser water remains deeper. But wind patterns, large ocean currents, and El Niño events can cause vertical mixing, pushing heat deeper into the ocean.

In 2024, El Niño played a role, shifting a warm pool of water from the western to central and eastern Pacific, further contributing to ocean expansion. Strong winds and currents in areas like the Southern Ocean also influenced how heat was distributed, NASA explained.