Continued burning of fossil fuels is likely to fuel even more extreme summers than that of 2018 because of its impact on the jet stream. The rapid disappearance of aerosols produced by pollution may, however, mitigate the impact until mid-century if countries like China phase out these fuels, according to scientists using climate models to predict changes in the occurrence of so-called Quasi-Resonant Amplification (QRA) events associated with persistent weather extremes.