Jet stream controls on European climate and agriculture since 1300 CE

The jet stream is an important dynamic driver of climate variability in the Northern Hemisphere mid-latitudes. Modern variability in the position of summer jet stream latitude in the North Atlantic-European sector (EU JSL) promotes dipole patterns in air pressure, temperature, precipitation, and drought between northwestern and southeastern Europe. EU JSL variability and its impacts on regional climatic extremes and societal events are poorly understood, particularly prior to anthropogenic warming. Based on three temperature sensitive European tree-ring records, we develop a reconstruction of interannual summer EU JSL variability over 1300-2004 CE (R² = 38.5%) and compare it to independent historical documented climatic and societal records, such as grape harvest, grain prices, plagues, and human mortality. Here, we show contrasting summer climate extremes associated with EU JSL variability back to 1300 CE, as well as biophysical, economic, and human demographic impacts, including wildfires and epidemics. In light of projections for altered jet stream behavior and intensified climate extremes, our findings underscore the importance of considering EU JSL variability when evaluating amplified future climate risk.