Extreme Weather Events in Argentina: Climate Change Impacts and Urgent Adaptation Needs

On March 7, 2025, Bahía Blanca, Argentina, experienced record rainfall and extreme heat, affecting over 300,000 people. The events underscored the growing threats posed by climate change, with researchers conducting an attribution study on heavy precipitation and rising temperatures. The findings suggest increased hazards due to urbanization and social disparities, emphasizing the need for investment in climate-resilient infrastructure and preparedness strategies.

On March 7, 2025, Bahía Blanca, Argentina, experienced an extraordinary rainfall event, with over 300 mm of rain falling in merely eight hours, about half of the city’s annual average. This incident marked the most substantial precipitation recorded in the area since 1956, resulting from a cold front following a span of hot, humid conditions. The preceding week had already witnessed over 80 mm of rainfall, which likely contributed to soil saturation before flooding occurred. Concurrently, northern Argentina and nearby regions had endured extreme heat, with temperatures surpassing 40°C, affecting 61 cities between February 19 and March 8, 2025.

The devastating rainfall impacted over 300,000 individuals, leading to 16 fatalities, the displacement of 1,400 people, and two individuals remaining missing. The financial cost of the damages in Bahía Blanca is estimated to be approximately $400 million. Simultaneously, 15 provinces issued heat alerts amidst record temperatures, causing widespread blackouts and traffic disruptions in Buenos Aires due to heightened energy demand. While there is no recorded data on heat-related mortality yet, prior studies reflect an increased risk associated with such extreme weather events.

To evaluate how much human-induced climate change influenced the severity and likelihood of both the significant rainfall and the heatwave, researchers from multiple countries, including Argentina and the United States, conducted an attribution study. This research focused on understanding changes in rainfall and heat patterns in the affected region during the preceding months, particularly emphasizing the summer season. The analysis assessed the extreme heat conditions over December to March and the heavy precipitation occurring intermittently throughout the first week of March.

Significantly, Northern Argentina, which includes Buenos Aires, faces greater risks due to the rise in extreme weather events, such as simultaneous heat and heavy rainfall. Factors contributing to this vulnerability include an aging populace, urbanization, and high population density. A considerable portion of the urban workforce operates within the informal economy, which amplifies their susceptibility to climate shocks.

The study concluded that the extreme heat observed is relatively uncommon, anticipated to recur once every 50 to 100 years under current climatic conditions. However, in a cooler climate of 1.3°C, such events would have been virtually improbable. Climate models project that increasing global temperatures will render extreme heat events more commonplace, with considerable rises as the climate warms further beyond 2.6°C above pre-industrial levels.

Conversely, the connection between climate change and the heavy rainfall is less definitive. Data from weather stations indicate a 7-30% increase in heavy rainfall intensity attributable to 1.3°C of global warming, although this is not consistently reflected in other datasets, which show a downward trend. Despite discrepancies, climate models generally align with the station data, predicting heightened likelihood and intensity of extreme rainfall in a warmer future.

These consecutive weather phenomena underscore the urgency of addressing the challenges posed by frequent and intense climate hazards in the region. Vulnerabilities are compounded by ongoing urbanization, insufficient infrastructure, and social inequities. As extreme weather events increase in frequency, it becomes crucial to invest in early warning systems and climate-resilient urban planning to mitigate risks associated with these hazards. Implementing green spaces within cities can provide temperature relief and help alleviate flood risks, essential even in densely populated areas.

In conclusion, the extreme heat and flooding events experienced in Argentina serve as stark reminders of the growing intensity and frequency of climate-related hazards attributable to human-induced climate change. The impacts of these events highlight the urgent need for enhanced preparedness and adaptive measures to mitigate the associated risks, particularly amidst conditions of urban vulnerability. Continuous investment in sustainable urban infrastructure, along with comprehensive climate action, remains crucial in confronting these unprecedented challenges.

Original Source: www.worldweatherattribution.org