The devastating floods that struck central Argentina earlier this month, claiming 16 lives, were intensified by climate change and could become more frequent in a warming world, according to a team of international scientists.
A study by the World Weather Attribution group found that extreme heat in the region before the flooding created a warmer, more humid air mass. This collided with a cold front from Argentina’s Patagonian region, triggering torrential rainfall in the port city of Bahía Blanca, located about 550 km (340 miles) south of Buenos Aires.
Juan Rivera, a scientist at the Argentine Institute for Snow Research, Glaciology, and Environmental Sciences (IANIGLA) and one of the report’s authors, explained that the high heat and humidity levels leading up to the disaster would have been nearly impossible without climate change.
According to Rivera, multiple days of temperatures exceeding 40°C (104°F) in northern and central Argentina, along with a humid heatwave just before the storm, caused moisture to accumulate. This resulted in an unprecedented 300 mm (11.8 inches) of rainfall over Bahía Blanca in just six hours.
Meteorological records indicate that such a flood had never been recorded before in the area. The study noted that extreme heat events like the one preceding the floods typically occur only once every 50 to 100 years. However, climate change is making them more frequent and intense.
The year 2024 was the hottest on record, with global temperatures surpassing 1.5°C (2.7°F) above pre-industrial levels for the first time. Scientists predict that 2025 could also rank among the hottest years ever recorded.
While the study confirmed a clear link between human-induced climate change and rising temperatures, its connection to heavy rainfall events was less certain due to inconsistencies in global meteorological data.
Despite these uncertainties, experts warn that the risk of consecutive extreme weather events in the same region is increasing. Friederike Otto, co-lead of World Weather Attribution, emphasized the need for preparation as the world continues to warm.
The report highlighted that Bahía Blanca’s rapid urbanization and lack of adequate infrastructure made it particularly vulnerable to heavy rainfall. The combination of an aging population, urban expansion, and high population density further increases the risks.
Rivera also pointed out that Bahía Blanca had experienced a severe storm in 2023, which brought winds exceeding 150 kph (93 mph). Both extreme weather events were fueled by climate change-related factors, including more frequent heatwaves and higher humidity levels. Further research is needed to better understand the growing risks associated with a warming climate.
