Abstract

Climate change is expected to increase drought frequency and severity, creating challenges for water management. The time of emergence (ToE) quantifies the point when the climate change signal becomes distinguishable from natural climate variability, based on a selected refence period, and may help inform local adaptation strategies. While ToE has been applied to hydroclimatic variables, its use for meteorological drought remains less explored. This study estimates the ToE of meteorological drought occurrence in Central-Southern Chile (29 degrees S-42 degrees S) using the annual Standardized Precipitation-Evapotranspiration Index (SPEI-12), derived from 30 general circulation models projections under SSP2-4.5 and SSP5-8.5 scenarios. Findings reveal that droughts of varying severity are projected to become more frequent, indicating a shift towards more arid conditions in the coming decades. Under SSP5-8.5, drought occurs approximately a decade earlier than under SSP2-4.5, particularly between 33 degrees S and 42 degrees S, exhibiting a north-to-south and west-to-east progression.