Causes of the Aggravation of Problems Resulting from the Climate Tragedy in Rio Grande do Sul
Translated from the original.
The climate tragedy that struck Rio Grande do Sul, which occurred in May, was marked by intense rains, floods and landslides. With 2 million people affected, 143 dead and more than R$ 12 billion in losses, it reaffirmed the urgency of responding to the climate emergency. The causes of the worsening of the problems resulting from this event are multifactorial, involving meteorological and structural factors, factors related to global climate change and possible administrative inefficiencies at the municipal level. The solutions, as well as actions to prevent analogous phenomena, need to be multifaceted.
Meteorological Factors
1. Atmospheric Blocking
• A mass of cold air from Argentina stayed parked over Rio Grande do Sul because of an atmospheric blocking caused by a mass of dry, hot air over central Brazil. This prevented the dispersion of the cold air mass, resulting in intense and prolonged rains, the largest since the 1940s.
2. El Niño Phenomenon
• The 2023 El Niño increased the temperatures of the Pacific Ocean waters, altering weather patterns and intensifying rainfall in southern Brazil. This phenomenon contributed significantly to climate variability and to the increased frequency of extreme events.
Structural Factors
1. Inadequate Infrastructure
• Insufficient Drainage System: The drainage infrastructure in urban areas, particularly in Porto Alegre, was unable to cope with the volume of water, resulting in severe flooding. Obsolete and insufficient drainage systems failed to carry off the water from the intense rains, exacerbating the floods. Evidently, this problem is aggravated by many people's carelessness about the proper disposal of garbage.
• Dam and Levee Failures: The failure of dams such as 14 de Julho, in Cotiporã, and the overflowing of protective levees contributed significantly to the floods. The inability of the suction pumps to operate efficiently during the intense flooding aggravated the problem.
2. Geography and Urbanization
• Geographic Position of Porto Alegre: Porto Alegre is located in a geographically vulnerable region, below other areas and major rivers of the State. The topography facilitates the accumulation of water, especially during extreme rains in the central and northwestern regions of Rio Grande do Sul.
• Disorderly Urban Expansion: Disorderly urban growth in vulnerable areas increases the risk of flooding. The occupation of areas near rivers and risk zones without adequate planning contributes to the severity of the floods.
From what we were able to observe up close of the reaction of the State Government of Rio Grande do Sul and of the Porto Alegre City Hall, there was adequate handling in responding to the crisis, although gigantic difficulties were imposed. It is difficult, however, to draw a picture of the specifics of the actions of each of the hundreds of affected municipalities.
The union of Rio Grande do Sul's civil society, in its multiple institutions, in supporting the homeless and displaced, as well as in monitoring the actions of the authorities, must be emphasized. Proof of maturity and democratic vigor.