By The editorial staff with AFP
Even if humanity manages to limit warming to 1.5 ° C compared to the pre-industrial era, sea levels will rise for centuries, flooding areas currently inhabited by half a billion people, scientists have warned. .
If the planet heats up by half a degree more, 200 million more city dwellers will be regularly managed by floods and made more vulnerable during storms, they wrote in the journal Environmental Research Letters. Asia, which has nine of the ten highest-risk mega-cities, will be the hardest hit. Most current estimates of sea level rise and the threats it poses to coastal towns run to the turn of the century and range from half a meter to less than a meter. But the phenomenon will continue beyond 100 under the effect of warming water and melting ice, regardless of the speed of reduction in greenhouse gas emissions. “About 5% of the world’s population currently lives on land distributed below the level that will be reached at high tide as a result of carbon dioxide already accumulated in the atmosphere by human activity,” said the lead author. from the article Ben Strauss, president and chief investigator of the independent organization of journalists and scientists Climate Central. The current concentration of CO2 is 50% higher than that of 1800 and the average temperature on the Earth’s surface has increased by 1.1ºC. That’s enough to raise the sea level by almost two meters, whether it will take two centuries or ten centuries, estimates Mr. Strauss. The 1.5 degree limit enshrined in the Paris Agreement and which countries around the world will try to maintain at the COP26 summit in Glasgow next month translates into a rise in water levels of nearly three meters in the long term. The Climate Central team also attempted to concretely illustrate the consequences linked to these different scenarios of rising water levels based on images of more historic or less flooded places (New window), depending on the severity of global warming. Climate Central ran simulations for 180 locations to show what the world might look like if the temperature rose 1.5 degrees, 3 degrees, or even 4 degrees. Museums, cathedrals, temples and famous public places around the world supposedly at risk of being partially or completely inundated. It should be noted that these simulations are carried out for global cities at sea level, therefore at low altitude and in the case where man does nothing to counter global warming.
Some examples of simulations The simulation was carried out in particular for the city of Antwerp. The inevitable scenario of a warming to 1.1 ºC is shown on the left. On the right, it reaches more like 3 ºC.