Amazon climate extremes: Increasing droughts and floods in Brazil’s state of Acre

The intensification of extreme climate events is already a reality throughout the world. In the Brazilian Amazon, the most frequent extreme events are linked to droughts and floods. This study expanded the documentation on extreme events of floods, water crisis, fires and forest fires in the state of Acre, in the southwestern Brazilian Amazon. We analyzed extreme weather events in state and municipal state-of-emergency and public-calamity decrees, reports of people who faced the impacts of these events, scientific articles, and press reports. The results show that the state of Acre recorded 202 extreme events between 1987 and 2023, with an increasing trend in the number and occurrence of various types of extreme events in the same year since 2010. Twenty-one state-of-emergency and public-calamity decrees were issued, with flood events being the most frequent. The cities of Rio Branco and Cruzeiro do Sul recorded 14 and 21 extreme events, respectively, or approximately one event every two years. These data show the urgency of implementing actions to adapt to climate extremes. Starting in 2005, the annual results indicate an increase in municipalities (counties) experiencing more than one type of extreme event, pointing to the need for effective public policies for adaptation and mitigation in the state of Acre.