Projected Intensification of Temperature and Precipitation Extremes at the Southern Tip of South America: Insights from CORDEX Regional Climate Simulations

Le résumé fourni par la source

Southern South America encompasses temperate forests, steppe ecosystems, peatlands, fjords, and marine environments that support unique biodiversity and human communities, containing one of the world’s largest freshwater reserves in the Patagonian Icefields. Its relevance makes climate change a major threat to both natural ecosystems and human populations. Nevertheless, future changes in climate extremes, considering the complex topographic patterns that shape regional climatic patterns, remain uncertain. This study used an ensemble of regional climate models to assess future changes in a set of 9 temperature and precipitation extreme indices under two emissions scenarios (RCP4.5 and RCP8.5) and three future time horizons (2026–2045; 2051–2070 and 2081–2100). Our results reveal a robust intensification of temperature extremes, with minimum temperature extremes projected to increase by more than 7 °C under the high-emissions scenario by the end of the century, accompanied by increases exceeding 30 summer days in the northeastern portion of the region. In contrast, precipitation extremes exhibit larger spatial variability and uncertainty, although robust reductions in the frequency of days with precipitation exceeding 20 mm partially explain the projected drying trend, while increases in 1- and 5-day maximum precipitation indicate more intense heavy rainfall events across the Patagonian steppe. These results have clear implications for the cryosphere and the biodiversity of the region.

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