The article reviews the state-of-the-art knowledge about 21st century climate change in the European Alps, focusing on the reliability and uncertainty of climate projections. It highlights that temperature, precipitation, global radiation, relative humidity, and related impacts such as floods, droughts, snow cover, and natural hazards will be significantly affected by global warming. Under the A1B emission scenario, the Alps are expected to warm by about 0.25 °C per decade until mid-century and 0.36 °C per decade in the second half of the century. The warming will be associated with changes in precipitation patterns, more intense precipitation extremes, and increased flooding potential in colder seasons. Record-breaking warm or hot seasons may become normal by the end of the 21st century, and droughts are expected to become more severe. Snow cover is projected to decrease below 1500-2000 m, and natural hazards related to glacier and permafrost retreat will become more frequent. These changes will have significant impacts on ecosystems and society, challenging their adaptive capabilities. The review also discusses the spatial and temporal variability of these changes, the altitude gradients of change, and the impacts on precipitation and temperature extremes, floods, droughts, snow, and natural hazards.The article reviews the state-of-the-art knowledge about 21st century climate change in the European Alps, focusing on the reliability and uncertainty of climate projections. It highlights that temperature, precipitation, global radiation, relative humidity, and related impacts such as floods, droughts, snow cover, and natural hazards will be significantly affected by global warming. Under the A1B emission scenario, the Alps are expected to warm by about 0.25 °C per decade until mid-century and 0.36 °C per decade in the second half of the century. The warming will be associated with changes in precipitation patterns, more intense precipitation extremes, and increased flooding potential in colder seasons. Record-breaking warm or hot seasons may become normal by the end of the 21st century, and droughts are expected to become more severe. Snow cover is projected to decrease below 1500-2000 m, and natural hazards related to glacier and permafrost retreat will become more frequent. These changes will have significant impacts on ecosystems and society, challenging their adaptive capabilities. The review also discusses the spatial and temporal variability of these changes, the altitude gradients of change, and the impacts on precipitation and temperature extremes, floods, droughts, snow, and natural hazards.