Recent south-central Andes water crisis driven by Antarctic amplification is unprecedented over the last eight centuries
Shijie Wang, Mao Hu, Feng Chen, Xiaoen Zhao, Martín A. Hadad, Fidel A. Roig, David M. Meko, Max C. A. Torbenson, Sergio Piraino, Heli Zhang, Xu Yang, Youping Chen, Weipeng Yue, Honghua Cao
Abstract
Rivers originating from the Andes Mountains are vital water sources for agricultural and societal needs in South America, yet are increasingly threatened by climate change. Here we reconstruct streamflow of the Negro River (Rió Negro) in northern Patagonia over the past 827 years using tree-ring records from the south-central Andes foothills. This reconstruction reveals an unprecedented decline in river flow in recent decades. Moisture from the El Niño–Southern Oscillation and the Southern Annular Mode provides a key water source, but temperature rise has increased atmospheric moisture demand and reduced availability. Antarctic amplification has further disrupted circulation patterns and accelerated warming, intensifying regional aridity. Since the 20th century, the Negro River has experienced a sustained flow reduction of approximately 10% per decade. Projections under various emission scenarios indicate continued decline, highlighting the urgent need for adaptive water management strategies to mitigate escalating water scarcity risks in the region. Climate change has led to a significant decrease in streamflow, particularly in the Negro River in the Andes, posing water scarcity risks and necessitating effective management strategies, according to streamflow reconstruction and tree-ring data analysis.