Past, present and potential future glacier cover in the entire European Alps has been assessed from an integrated approach, combining in-situ measurements, remote sensing techniques and numerical modeling for equilibrium line altitudes. Alpine glaciers lost 35% of their total area from 1850 until the 1970s, and almost 50% by 2000. Total glacier volume around 1850 is estimated at some 200 km³ and is now close to one-third of this value. From the model experiment, we show that a 3°C warming of summer air temperature would reduce the currently existing Alpine glacier cover by some 80%, or up to 10% of the glacier extent of 1850. In the event of a 5°C temperature increase, the Alps would become almost completely ice-free. Annual precipitation changes of ±20% would modify such estimated percentages of remaining ice by a factor of less than two.