30 to 33°C from Pays de la Loire to the Paris region and even 37°C announced locally this week in the South-West. It’s hot. Very hot even. And not just in France. In Morocco, although accustomed to droughts, the alert level has been reached. The United States is facing a heat wave, floods and devastating fires. Did you say climate?
“In France, we are only in mid-June and half of the territory can be considered in extreme drought. And this is now nothing exceptional. We will increasingly face multi-year cycles like the one we experienced between 2016 and 2020” , explains David Moncoulon, research and development director and doctor of science in hydrology at the Caisse centrale de réassurance.
No country, not even the most temperate, escapes the consequences of climate change. Associated with Météo France, the CCR endeavors to model the repercussions of this rise in temperature in the area of natural disasters. For this work, the researchers adopted the IPCC scenario predicting a rise in temperatures between 1.4°C and 2.6°C in 2050.
The cost of natural disasters could increase by 50%
Météo France has generated with its Arpège Climat model, 400 possible years with a current climate and 400 other years with a 2050 climate. the CCR. They have been rolled out in the major French regions.
“If nothing is done, the average cost of natural disasters is expected to increase by 50% by 2050, from €1.2 billion to €1.8 billion. »
But certain exceptional events such as the centennial flood of the Seine in 1910 could generate 30 billion euros in damage. The cost of a flood of the Loire equivalent to that of 1856 would be in a range between 3 to 5 billion euros. Runoff is also one of the new elements to consider. “For the past fifteen years, half of flood-related claims have been located outside flood-prone areas. » In question, urbanization, soil sealing, the disappearance of hedges. Hence the importance of presenting maps and bringing together all the stakeholders: elected officials, regional management of the environment, planning and the environment (Dreal), chambers of agriculture, town planners to develop prevention programs.
Major natural disasters have affected France in recent years: flooding of the Seine in June 2016, drought in 2017, hurricane Irma in September 2017, flooding of the Seine and the Marne in January 2018, torrential rains with catastrophic consequences in the Roya and Vésubie valleys in the hinterland of Nice in September 2021.
Salty bill for the Atlantic facade
The Atlantic coast, under the effect of demographic change and the rise in sea level, would see the damage increase by more than 60% by 2050. The increase in vulnerability in Ile-de-France would result by an increase of more than 40%. The increase would be around 30% for the departments around the Mediterranean, observes the Caisse centrale de réassurance.
This forward-looking work is essential in the context of public policies. It makes it possible to measure the consequences of not doing anything.