Lake expansion underpinned the Silk Road prosperity during a drought period

The ancient Silk Road (138 BCE–1539 CE) served as a critical corridor for trans-Eurasian exchange, sustained by oasis settlements across arid Central Asia (ACA). However, its peak prosperity during the Tang Dynasty (618–907 CE) amidst regional drought presents a hydroclimatic paradox. Here we provide a high-resolution lake-level reconstruction from Jili Lake in ACA—a direct indicator of past water availability—combined with other robust palaeoclimate records. Our findings reveal that, despite persistent aridity from ca. 600 to 900 CE, warming-enhanced meltwater from mountain cryosphere triggered a pronounced lake expansion (~20 m level rise, ~80% area increase), creating well-watered corridors that supported thriving trade networks. In contrast, cold intervals suppressed meltwater generation (ca. 350–500 and ca. 1200–1550 CE), leading to oasis desiccation and trade disruption. These hydroclimatic dynamics decouple water availability from atmospheric humidity/precipitation, highlighting the essential role of meltwater in sustaining oasis civilizations. Moreover, the depletion of meltwater resources during the latter part of the prolonged warm phase (ca. 600–1100 CE) offers insights into the vulnerability of meltwater-dependent systems to ongoing anthropogenic warming. Enhanced meltwater in arid Central Asia during a warm and dry period in the Tang dynasty between CE 600 and 900 created well-watered corridors and supported Silk Road prosperity, according to a high-resolution lake-level record from Jili Lake, China