With the help of five satellites, NASA carries out annual measurements of the global sea level. According to The latest analysis the sea level continued to rise in 2024 with an increase rate of 0.59 centimeters per year, compared with the expected 0.43 centimeters per year.
“The increase we saw in 2024 was greater than we expected,” said Josh Willis, sea level researcher at NASA, in a press release.
“Every year looks a little different, but it is clear that the sea continues to rise and that it happens at higher and higher speeds.”
“Warmest year”
However, Magnus Hieronymus, research leader in the sea climate at SMHI, is not as surprised.
– What is clear is that 2024 was a very warm year – the warmest we have measured. It was also an El Niño year, so you would get a high sea level rise was quite expected, he says.
How serious is it?
-In a historical context, the middle rise during the 20th century was about 1.5 millimeters per year and perhaps around 3 millimeters over the past 30 years-since then it has gone faster and faster.
– We have a sea level that accelerates upwards now. Then it is probably far too early to say if they are almost 0.6 centimeters in one year is a trend or if it is only an extreme year.
Expands at heat
According to NASA, the rapid increase during record warm 2024 is mainly due to the fact that seawater takes up more space when heated, so -called thermal expansion. Last year, two -thirds of the increase was due to this, unlike in recent years when the increase to two -thirds had its basis in melting ice and glaciers.
– When we heat the planet, about 90 percent of surplus energy ends up in the sea and this leads to thermal expansion. An extremely warm year we thus get extremely much sea level rise.
The consequence of rising sea levels is, among other things, an increased risk of flooding in coastal areas where people live.
Has doubled
Since NASA began its satellite measurements of the sea level in 1993, the annual increase has more than doubled. In total, the global sea level has risen by 10 centimeters since then.
The far -reaching trend with accelerating sea level increases is driven by climate change, but it is difficult to answer how individual years are affected, according to Magnus Hieronymus.
– There is so much short -term variability that also comes into play. But the far -reaching trend is driven by human emissions.