Six hundred kilometers south of Lake Titicaca and more than 3700 m above sea level, the Intersalar region, between the two large salt lakes of Uyuni and Coipasa, is dotted with fields of quinoa and numerous communities. Today, this region is the main producer of quinoa exported throughout the world. Close to these villages, numerous archaeological settlement sites bear witness to an ancient human occupation, dating from between the 13th and 15th centuries. Within an area of 60 x 40 km, the researchers studied 48 sites, at which they identified more than 4500 archaeological granaries that were used for quinoa storage. But was the climate at that time similar to the current climate? All climate proxies agree and characterize the period from 1200-1450 CE as dry. Within this drier time interval, the rise of rainfed agriculture in the southern altiplano coincided with a catastrophic volcanic event, the eruption of the Samalas Volcano in Indonesia (1257 CE), which initiated climatic changes lasting several decades, with drops in temperature and precipitation on a global scale.