Extreme events in Europe have been shaped by the jet stream for 700 years

The jet stream — a band of strong winds high above Earth’s surface — can shift and create opposing summertime climate conditions in northwest and southeast Europe. Tree-ring data reveal that the jet stream has driven this climate dipole for more than 700 years, resulting in contrasting patterns in weather, agricultural and societal extremes. Anomalous shifts in upper atmospheric winds have historically been associated with climate and agricultural extremes.