Sea levels rise by an “unexpected” amount in 2024: NASA March 14, 2025

In a recent period of three decades, from 1993 to 2023, the average sea level around the world has risen by about 10 cm in total, according to NASA (Paul ELLIS)

By AFP - Agence France Presse

Sea levels rise by an “unexpected” amount in 2024: NASA

Global sea levels rose more than expected in 2024, the hottest year ever recorded on Earth, according to an analysis released Thursday by US space agency NASA.

On its website, the National Aeronautics and Space Administration explained that last year's rise “was due to an unusual amount of ocean warming, combined with meltwater from land ice, such as glaciers”.

According to the analysis conducted by NASA, which monitors rising water levels using satellite images, the world's seas rose by 0.59 centimeters in 2024, well above the 0.43 cm predicted by scientists.

“Each year is a little different, but what is clear is that the ocean continues to rise, and the rate of rise is getting faster and faster,” said researcher Josh Willis, from NASA's Jet Propulsion Laboratory.

Rising sea levels are among the consequences of human-induced climate change, and the oceans have risen in line with the increase in the Earth's average surface temperature - a change which, in turn, is caused by greenhouse gas emissions.

Over a recent period of three decades, from 1993 to 2023, average sea levels around the world rose by around 10 cm in total, according to NASA.

The phenomenon is mainly caused by two factors: the melting of glaciers and polar ice caps, which increases the flow of fresh water into the oceans; and the expansion of seawater due to heat, a process known as thermal expansion.

In recent years, the observed rise in sea levels has been caused mainly by the first factor and less by the second, according to NASA.

“But by 2024, these contributions have reversed, with two-thirds of the sea level rise coming from thermal expansion,” said the agency.

The year 2024 was the hottest on record since records began in 1850.

Sea levels are expected to rise further as humanity continues to emit greenhouse gases, threatening vast populations living on islands or along the coast.

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