NASA said on Thursday that the average rise in global ocean levels reached 0.76 cm between 2022 and 2023, a “big jump” compared to other years, due to the El Niño phenomenon and climate change.
Ocean levels have risen on average by 9.4 cm since 1993, according to these data based on satellite observations.
The main cause is climate change, which involves the melting of ice (ice caps and glaciers), but also the expansion of the oceans as a result of heat absorption.
Sea level rise is occurring at an increasing rate: its rate has doubled between 1993 (0.18 cm per year) and now (0.42 cm).
Nadia Vinogradova-Schafer, head of the team responsible for this file at NASA, said in a statement: “The current pace means that we are on track to add another 20 cm to the level of the global ocean by 2050.”
She stressed that this “will increase the frequency and consequences of floods around the world.”
Between 2022 and 2023, the observed increase would be equivalent to a quarter of Lake Superior, the largest of the Great Lakes, flowing into the oceans.
This increase represents slightly less than four times the level recorded in the previous year (+ 0.21 cm between 2021 and 2022). That year, the Nina phenomenon was active.
“During La Niña, rain that would normally fall in the oceans falls on land, temporarily removing water from the oceans,” explained Josh Willis, a researcher on the subject at NASA.
“During El Niño years, much of the rain that normally falls on land ends up in the ocean, causing ocean levels to rise temporarily,” he added.
