Europe's biggest glacier, the Great Aletsch, coils 24 km through the Swiss Alps, but this mighty river of ice could almost vanish in the lifetimes of people born today because of climate change. Although the ice is nearly 1 km thick in places, it is melting more quickly than it can be replenished. The glacier has retreated about 3 km since 1870 and that pace is quickening. This is feeding more water into the oceans and raising world sea levels. (Photo/CFP)
Day|Week