Past ice sheets have retreated rapidly, raising global sea level at rates >1 cm per year, with marine ice sheets collapsing and terrestrial ice sheets retreating in a more gradual fashion.

The extent of sea ice stretching across Earth’s polar regions reached an all-time minimum in February, researchers said Wednesday, offering the latest evidence of how the warming world is ...

This story appears in the January 2018 issue of National Geographic magazine. We see evidence of the kill first: a shockingly broad spread of scarlet, probably the blood of a ringed seal, on snow ...