The role of ocean warming and marine heatwaves for extreme events over land: Earth observations document the increasing warming of the oceans and new regional records are constantly being broken. Temporally and spatially limited warming events in the ocean, so-called marine heatwaves, are increasingly becoming the focus of research and public attention. In the context of global change, the anomalously warm seawater provides a large potential for evaporation, which is redistributed by an atmosphere that can carry more water vapor in a warmer climate. This physical principle alone results in a potential for the increased occurrence of extreme precipitation events, with regional details depending on dynamic changes in wind systems or the characteristics of storms. The expansion of the oceans due to warming also leads to rising sea levels, and the higher water levels are superimposed on storm surges as extreme events. Oceanic temperature anomalies can also influence heat waves over land via atmospheric teleconnections.