(Paris) Climate change has increased the likelihood, potentially “up to 50 times”, of rains as intense as those that caused two poorly maintained dams to break in Libya, killing thousands in Derna, according to a study published Tuesday by a network of scientists specializing in this type of analysis.
World Weather Attribution (WWA) researchers have not been able to precisely estimate the influence of global warming, the phenomenon being too brief and too localized for most existing climate models, but also due to a glaring lack of observational data.
The lack of influence of climate change caused by human activity cannot therefore be completely ruled out, but scientists do not doubt the link, since “increased temperatures generally lead to more abundant rain”, “studies predict heavier rains in the region,” and regional weather data already shows this trend at work.
Concerning Libya, scientists found that “climate change increased the probability of the event occurring up to 50 times, with up to 50% more rain during this period”.
To analyze the effect of warming in amplifying extreme events, WWA uses climate data and models to compare the current climate, about 1.2°C warmer than since the pre-industrial era, with that of the past.
On September 10, when Storm Daniel unleashed a deluge on northeastern Libya, two dams burst near Derna, causing a tsunami-sized wave along a usually dry wadi, causing thousands of deaths.
“After a summer of heatwaves and devastating fires with a clear imprint of climate change, measuring the contribution of climate change to these floods has proven more difficult,” admitted Friederike Otto, of the Grantham Institute of Climate Change. Imperial College London. “But there is no doubt that reducing vulnerability and building resilience to all types of extreme weather is essential to saving lives in the future.”
The study also estimates that global warming has “made up to 10 times more likely” the intensity of rains in Greece, Bulgaria and Turkey, also hit by exceptional flooding due to Storm Daniel.
“In this vast region, which includes parts of the three countries, the event is now relatively common”, and can now recur “once every ten years”, estimates the study. For central Greece, the most affected, “the event is less likely” (approximately once every 80-100 years).
On the other hand, for Spain, a complete analysis could not be carried out, because “the available climate models poorly represent heavy precipitation on time scales of less than one day”.