Climate change has made the heavy rains, which led, among other things, to the devastating floods in Libya, much more likely: This is the result of a rapid study by scientists at World Weather Attribution Initiative (WWA), an international climate research team.
At the beginning of September there was a low pressure system over the Iberian Peninsula as well as the storm Daniel over the eastern Mediterranean brought heavy rain to various countries, particularly Spain, Greece, Bulgaria, Turkey and Libya. In Greece, 17 people died in floods, and there were also several deaths in Spain, Bulgaria and Turkey. By far the hardest hit was Libya, where two dams burst as a result of the floods and thousands died; 10,000 people are still missing.
For the current analysis, WWA researchers led by Mariam Zachariah from Imperial College London compared the current situation, in which the earth has already warmed by around 1.2 degrees, with the pre-industrial climate using climate data and simulations. The method is considered scientifically established. For Libya, the calculation showed that such an event is rare, even in the current climate; statistically, despite warming, it should only occur every 300 to 600 years. However, without climate change, it would have been up to 50 times less likely. In large parts of Greece, Bulgaria and Turkey, such an event can be expected about every five to ten years in today’s climate; climate change has made it up to ten times more likely.
Deforestation, urbanization, conflicts: climate change wasn’t the only thing that played a role
The researchers admit that the uncertainty in these estimates is high. However, they argue that a role of the climate crisis in rainfall is at least plausible: After all, due to warming, one has to assume that rainfall will generally become ten percent more intense – because warmer air can absorb more water. Studies also show that extreme rainfall increases with warming.
But humans have not only contributed to the catastrophic consequences of storms through climate change. According to Zachariah’s team, in Greece, for example, deforestation and urban growth have changed the landscape, causing more people and goods to be exposed to flooding and water to drain less easily. In Libya, the ongoing conflicts in the state would have increased the effects, as the dams, for example, were not adequately maintained. The political situation is also blocking national planning for adaptation to climate change.
In addition, the two broken dams that were built in the 1970s may not have been designed for such an extreme event. The disaster points to the challenge of building infrastructure not only for the past and present, but also for the future. In Libya, this means planning for the long-term decline in average rainfall, but also for the increasing extreme rainfall – a difficult task, especially for a crisis-stricken state.
Experts comment positively on the study. “This is first-class research,” says Karsten Haustein, climate researcher at the University of Leipzig. It follows established WWA principles for such studies, which are based on peer-reviewed methods and data of the highest quality.
With material from the British Science Media Center