Climate change fuelled high temperatures that were partly responsible for extreme rainfall that hit the port city of Bahía Blanca this month, killing at least 16 people, a report published Thursday concluded.
Bahía Blanca, home to some 350,000 people, was hit by torrential downpours on March 7 that in just a few hours doubled the annual average.
Two sisters aged one and five swept away with their mother and a man who had tried to save them, are still officially listed as missing.
The deluge flooded the city’s main hospital, the Hospital Interzonal Dr. José Penna, tore down bridges, damaged roads and houses and swept away pretty much everything in its path.
Thousands of people were evacuated to temporary shelters.
"The extreme summer temperatures that hit northern Argentina and other parts of South America between December and early March would have been virtually impossible without global warming," said a report by the World Weather Attribution, a network of researchers examining links between environmental change and extreme weather events.
"The same applies to the humid heatwave that immediately preceded the rain event."
The report, composed by 17 scientists, warned such warm summers will become more common in a few decades "if the world continues to warm at the current rate."
The scientists could not conclusively say that the intense rainfall itself had been fuelled by human-induced global warming.
It was, however, "the most likely explanation, since a warmer atmosphere holds more moisture and leads to more intense downpours."
A collision between warm and cold air masses in March triggered a massive rainfall that hit Buenos Aires Province, where Bahía Blanca is located. At the time, yellow heat alerts were in effect across several regions.
The resulting storm, which dumped 300 millimetres of rain in eight hours, caused more than US$400 million in damages, according to the provincial government.
"Climate change favours this prevalence of warm, humid air, which with the advance of the cold front generates floods of greater magnitude," Juan Rivera, a researcher at the Instituto Argentino de Nivología, Glaciología y Ciencias Ambientale (“Argentine Institute of Nivology, Glaciology and Environmental Sciences”), explained at a press conference.
Bahía Blanca suffered another extreme event in December 2023, recording winds of more than 150 km/h. According to Rivera, both phenomena had common characteristics that could be linked to climate change.
Asked about infrastructure failures that could have played a role in the virulence of this month's flooding, local Peronist lawmaker Álvaro Díaz said that the amount of rainfall created situation that "exceeded everyone's expectations.”
"The city drained in a positive way, but the amount of water was too overwhelming for the Maldonado canal and the Napostá stream to resist," he said, referring to the waterways the city uses to drain the water. "A river ran past my front door," he added.
Under the Paris accord on climate change, the world agreed to try and keep warming to no more than 1.5 degrees Celsius (2.7 degrees Fahrenheit) from the industrial revolution, when humanity started burning large amounts of planet-warming fossil fuels.
Scientists say the risks of climate change increase with every fraction of a degree, and exceeding 1.5C over a decades-long period would greatly imperil ecosystems and human societies.
"As the planet warms and extreme weather becomes more frequent, governments need to prepare for the occurrence of simultaneous events," concluded the report.
– TIMES/AFP
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