Recently, France24 cited a report from the US National Aeronautics and Space Administration (NASA) saying that sea levels rose 76mm in the 2022-2023 period, nearly four times higher than in the 2021-2022 period, due to the strong El Nino weather phenomenon and warming climate.
NASA's analysis is based on more than 30 years of satellite observations, with the first launch in 1992 and the latest in 2020. Sea levels have risen about 101mm since 1993. The rate of sea level rise is also faster, more than doubling from over 1.7mm/year in 1993 to over 4.3mm/year at present.
The direct cause of this sudden increase is the El Nino phenomenon, which will replace the La Nina phenomenon from 2021-2022, when sea levels will rise by about 2.03mm. In addition, human factors are also one of the causes of this situation.
At the current rate, global average sea levels are on track to rise by 20cm by 2050, which would be double the rate over the next three decades compared to the last century, making floods more frequent and catastrophic in the future than they are today, said Nadya Vinogradova Shiffer, head of NASA's sea level monitoring team and ocean physics program in Washington.
During El Nino years, large amounts of rain that would normally fall on land flow into the ocean, causing temporary sea level rises, said sea level researcher Josh Willis at NASA's Jet Propulsion Laboratory (JPL).
Long-term datasets like this 30-year satellite record allow us to distinguish between short-term impacts on sea level, like El Nino, and long-term trends, says Ben Hamlington, head of NASA's JPL sea level monitoring team.
Technological innovations have brought greater accuracy to measurements over the years. For example, radar altimeters reflect microwaves from the sea surface, then record the time the signal travels back to the satellite, as well as the strength of the reflected signal.
The experts also cross-checked their data with other sources such as tide gauges, satellite measurements of atmospheric water vapor and Earth's gravity .
Quoc Tiep (according to Hanoi Moi, Thanh Nien)
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