Study Says Climate Change Made Libya Flood Catastrophe “50 Times More Likely”

In a recent report by the World Weather Attribution group, climate scientists have revealed that human-induced climate change amplified the ferocity of the devastating storm that struck the Libyan city of Derna in early September 2023, resulting in thousands of casualties. Their findings indicate that climate change made a storm of this magnitude up to 50 times more likely and contributed to a 50% increase in rainfall.

Talking in the light of the report, Jagan Chapagain, Secretary General of the International Federation of Red Cross and Red Crescent Societies (IFRC) said “What happened in Derna should be a wake up call for the world on the increasing risk of catastrophic floods in a world changed by climate change.”

Floods in Libya after Storm Daniel, September 2023. Photo: Libyan Red Crescent Society

The torrential rain brought by Storm Daniel was exacerbated by human-caused greenhouse gas emissions, leading to catastrophic flooding, the World Weather Attribution group report said.

The scientists employed computer simulations to assess the increased likelihood of such an event in the current climate compared to pre-warming conditions. They found that climate change had made this storm up to 10 times more probable and had intensified the rainfall by up to 40%.

According to the study, storms of this intensity are now relatively common for the Mediterranean region, with an expectation of one occurring approximately every 10 years. The prolonged presence of Storm Daniel over the Mediterranean allowed it to absorb additional energy from sea temperatures that were two to three degrees above the September average. This extra warmth fueled stronger winds and increased the air’s moisture-holding capacity.

Julie Arrighi, Interim Director at the Red Cross Red Crescent Climate Centre which had researchers working on the World Weather Attribution report said:

“This devastating disaster shows how climate change-fuelled extreme weather events are combining with human factors to create even bigger impacts, as more people, assets and infrastructure are exposed and vulnerable to flood risks. However, there are practical solutions that can help us prevent these disasters from becoming routine such as strengthened emergency management, improved impact-based forecasts and warning systems, and infrastructure that is designed for the future climate.”

When Storm Daniel made landfall on the northern coast of Libya, it unleashed approximately 400 mm of rainfall on Derna within just 24 hours. To put this into perspective, the average rainfall for September in the city is a mere 1.5 mm, as reported by Nasa’s Earth Observatory.

The catastrophic impact of this extreme weather event underscores the perilous combination of intense weather and vulnerable populations, particularly in conflict-ridden regions. In Libya, years of political instability and civil war have exacerbated the vulnerability of its people to natural disasters.

Furthermore, the inadequate maintenance of two dams in the river above Derna, coupled with the construction of houses in flood-prone areas, exacerbated the devastation when the dams burst. Tens of millions of cubic meters of water inundated the city, sweeping away entire neighbourhoods.

Jagan Chapagain said, “The disaster in Derna is yet another example of what climate change is already doing to our weather. Obviously multiple factors in Libya turned Storm Daniel into a human catastrophe; it wasn’t climate change alone. But climate change did make the storm much more extreme and much more intense and that resulted in the loss of thousands of lives. That should be a wake up call for the world to fulfil the commitment on reducing emissions, to ensure climate adaptation funding and tackle the issues of loss and damage.”

Despite some mathematical uncertainties in their findings due to the limited availability of data and the challenges of representing rainfall in small-scale climate models, the scientists are confident that climate change played a substantial role in this catastrophe. There is strong evidence linking higher temperatures to heavier rainfall, and previous studies have demonstrated that climate change intensifies the impact of severe weather events like Storm Daniel.

The report highlights the urgent need to address climate change, adapt infrastructure to future climate conditions, and improve emergency management and communication in vulnerable regions to mitigate the growing risk of extreme weather-related disasters.