Article: In April and May 2024, the Brazilian state of Rio Grande do Sul was hit by unprecedented flooding, displacing nearly 600,000 people and causing more than 180 deaths. These floods, among the most severe in Brazil\u2019s history, affected 90% of the state\u2019s municipalities, with record rainfall equivalent to three months of rain in just two weeks. In Porto Alegre, the capital, these rains marked the wettest start to May in 63 years.<\/p>\n
The causes of this extreme event are multiple. A probabilistic attribution study reveals that global warming, with a 1.2\u00b0C increase compared to the pre-industrial era, doubled the likelihood of such rainfall while increasing its intensity by 12%. The El Ni\u00f1o phenomenon, particularly intense in 2023-2024, also played a key role, doubling the probability of the event compared to a neutral year.<\/p>\n
The exceptional rainfall was fueled by a persistent high-pressure system over the South Atlantic, strengthening the trade winds and transporting moisture from the tropical ocean to central Brazil and then to Rio Grande do Sul. This mechanism, combined with cold fronts blocked by the high pressure, caused rainfall accumulations over several days, overwhelming the capacity of dams and local infrastructure.<\/p>\n
The floods exposed structural and social vulnerabilities. The poorest populations, particularly those living in informal settlements or indigenous communities, were the hardest hit. Flood protection infrastructure, such as the Mau\u00e1 wall in Porto Alegre, showed its limitations, with technical failures worsening the damage. Additionally, deforestation and urbanization have reduced soil absorption capacity, amplifying risks.<\/p>\n
Climate projections indicate that such events could become more frequent and intense as warming continues. Models suggest an increase in extreme rainfall in southern Brazil, with greater impacts on populations and local economies. The 2024 floods highlight the urgency of investing in equitable adaptation measures and modernizing infrastructure to reduce future risks.<\/p>\n
These unprecedented floods underscore the need to better understand the interactions between climate change, natural phenomena like El Ni\u00f1o, and human factors. They highlight the importance of public policies that integrate both climate risk management and the reduction of social inequalities to build more resilient cities.<\/p>\n
\n DOI:<\/strong> https:\/\/doi.org\/10.1038\/s44304-025-00162-8<\/a>\n<\/p>\n \n Title:<\/strong> Climate change and El Ni\u00f1o behind extreme precipitation leading to major floods in southern Brazil in 2024\n<\/p>\n \n Journal:<\/strong> npj Natural Hazards\n<\/p>\n \n Publisher:<\/strong> Springer Science and Business Media LLC\n<\/p>\n \n Authors:<\/strong> Ben Clarke; Clair Barnes; Regina Rodrigues; Mariam Zachariah; Lincoln Muniz Alves; Rein Haarsma; Izidine Pinto; Wenchang Yang; Maja Vahlberg; Gabriel Vecchi; Karina Izquierdo; Joyce Kimutai; Sjoukje Philip; Sarah Kew; Jo\u00e3o Biehl; Miqueias Mugge; Friederike E. L. Otto<\/p>\n","protected":false},"excerpt":{"rendered":" Title: Climate Change and El Ni\u00f1o Behind Record Flooding in Brazil in 2024 Article: In April and May 2024, the Brazilian state of Rio Grande do Sul was hit by unprecedented flooding, displacing nearly 600,000 people and causing more than 180 deaths. These floods, among the most severe in Brazil\u2019s history, affected 90% of the… Continue reading Title: Climate Change and El Ni\u00f1o Behind Record Flooding in Brazil in 2024<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[6,11,9,8,10,7],"tags":[],"class_list":["post-38","post","type-post","status-publish","format-standard","hentry","category-environnement","category-evenements","category-humain","category-litterature-scientifique","category-politique","category-societe","entry"],"_links":{"self":[{"href":"https:\/\/wlr.world\/en\/wp-json\/wp\/v2\/posts\/38","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/wlr.world\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/wlr.world\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/wlr.world\/en\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/wlr.world\/en\/wp-json\/wp\/v2\/comments?post=38"}],"version-history":[{"count":0,"href":"https:\/\/wlr.world\/en\/wp-json\/wp\/v2\/posts\/38\/revisions"}],"wp:attachment":[{"href":"https:\/\/wlr.world\/en\/wp-json\/wp\/v2\/media?parent=38"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/wlr.world\/en\/wp-json\/wp\/v2\/categories?post=38"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/wlr.world\/en\/wp-json\/wp\/v2\/tags?post=38"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}