Floods like here in the Chinese city of Fuzhou will become more frequent in the future
Photo: picture alliance / dpa
Sea level rise is a long-term threat.
A new study that appeared in the journal "Environmental Research Letters" shows: Even if mankind succeeds in limiting the global temperature increase to 1.5 degrees Celsius by the year 2100, the sea level will not rise by the end of the century stop being.
Many scientific estimates and surveys on the rise in sea level refer to the period up to 2100. Depending on various variables, a rise of less than one meter is calculated by then.
However, due to the warming of the water and the melting of the ice, the level will continue to rise beyond the year 2100, warn the researchers - for the time being regardless of how quickly greenhouse gas emissions are reduced.
Nine out of ten heavily affected metropolises are in Asia
The region that the sea level rise will hit hardest is the study after Asia. Nine of the ten coastal metropolises that are most threatened by flooding are located there. China, India, Indonesia and Vietnam and Bangladesh had the largest population living below the predicted flood line, the survey said.
Assuming a scenario with still high or even increasing emissions, global warming of around 4 degrees Celsius and an average rise in global sea level of 8.9 meters within a period of 200 to 2,000 years can be expected.
This would mean that 50 large cities would have to "protect themselves against a worldwide unprecedented level of flooding, if this is possible," write the authors of the study.
Should the affected cities fail to protect themselves from the floods, there is a threat of “almost complete loss of their area”.
more on the subject
Energy, mobility, building, housing: the new government urgently needs to solve these climate problems.By Susanne Götze and Hilmar Schmundt
Report on the state of the seas: Too warm, too acidic, increasingly difficult to live in
Inventory: How badly climate change is affecting the Baltic SeaBy Christoph Seidler
Based on mean sea level projections, at least one major nation on every continent would be exceptionally vulnerable, excluding Australia and Antarctica.
Many small island states would be threatened with almost complete loss.
Every twentieth person is threatened today
Around five percent of the world's population already live in areas that could face severe flooding in the future, said the study's lead author, Ben Strauss.
Strauss is also President of the science organization Climate Central.
"The concentration of CO2 is 50 percent higher today than it was in 1800, and the average surface temperature of the earth has risen by 1.1 degrees Celsius," he said.
That is enough to raise the sea level by almost two meters, "regardless of whether it takes two or ten centuries".
more on the subject
Worldwide droughts and floods: Where the climate changes - and where we still have a chanceBy Francesco Collini, Johann Grolle and Thomas Milz
If the earth warms up by half a degree more - i.e. by two degrees Celsius compared to the pre-industrial value - the houses and apartments could be flooded by half a billion people.
The scientists calculated that around 200 million other inhabitants of coastal cities would then regularly fall victim to flooding.
Storms could also become an even bigger problem.
"In Glasgow and until the end of this decade we have the opportunity to either help the next hundred generations or to betray them," said Strauss with a view to the upcoming COP26 world climate summit.
There is a map on the Climate Central website showing models for the various emission scenarios.
The rising sea level also has consequences for regions in Germany.
vki / AFP