Europe's Melting Glaciers: Aletsch

BETTMERALP, SWITZERLAND - AUGUST 21: A rivulet of meltwater on the surface of the retreating Aletsch glacier on August 21, 2019 near Bettmeralp, Switzerland. At over 22km in length, the Aletsch is Switzerland's longest glacier. Since 1850 it has diminished approximately 2.5 kilometers in length and lost about a quarter of its surface area. It currently shrinks vertically at a rate of about four meters per year. While the retreat of glaciers across Europe is part of a natural process that began with the end of the Little Ice Age in the mid-19th century, the acceleration of the melting since the 1960s is a phenomenon many scientists attribute to human activity that is further warming Earth's climate. (Footage by Sean Gallup/Getty Images)