During the last ice age's maximum, at a time when Scandinavia was covered by a gigantic ice sheet, ice-free conditions prevailed in the Polar Ural Mountains. John-Inge Svendsen writes about a unique climate archive from Arctic Russia.

The living conditions for marine microorganisms in the Southern Ocean may dramatically worsen by the end of the century. More acidic water can make their territories shallower.

Almost one-fifth of the world’s population depends on rivers coming from the Himalayas and the Tibetan Plateau. Yet, only one in a thousand glaciers and lakes in this region have monitoring stations and constraints on the hydrological cycle are poor, Hans Christian Steen-Larsen and colleagues writes in a comment in Nature.