Climate change has ‘doubled’ the likelihood of historic floods in southern Brazil

El Niño, a natural meteorological phenomenon associated with warming of the ocean surface, exacerbated precipitation by 3 to 10% in the south of the country.

In two weeks, the equivalent of three months of precipitation fell on the state of Rio Grande do Sul, in Brazil. According to a study published Monday June 3 by the scientific network World Weather Attribution (WWA), these historic floods in the south of the country have been made twice as likely and 6 to 9% more intense by climate change.

Dantean floods have submerged entire towns and devastated fields as far as the eye can see in Rio Grande do Sul, an agricultural state as large as the United Kingdom. “An extremely rare episode, which should only occur once every 100 to 250 years”, according to the study. The latest official report shows 172 dead and 42 missing. Nearly 600,000 people had to leave their homes.

El Niño, a natural meteorological phenomenon associated with warming of the ocean surface, exacerbated precipitation by 3 to 10% in southern Brazil, according to this network which analyzes the link between this type of disaster and climate change. “Climate change is amplifying the impact of El Niño in southern Brazil, making an extremely rare episode more frequent and more intense”says Regina Rodrigues, one of the authors of the study.

According to this researcher from the University of Santa Catarina, in southern Brazil, three of the four worst floods in the history of Porto Alegre, capital of Rio Grande do Sul, took place “the last nine months”which is “very rare”.

This is despite the fact that El Niño has weakened in recent months, with the current cycle appearing to be coming to an end, paving the way for the likely return of the opposite phenomenon, La Niña, synonymous with cooler global temperatures.