Why is Greenland icy and Iceland green?

The names are older than the modern climate contrast suggests and were not chosen as descriptions. According to the Icelandic sagas, Erik the Red, exiled from Iceland for manslaughter around 982, explored the coast of the land to the west and named it Greenland deliberately to make it sound appealing to potential settlers, a piece of tenth-century promotion that the sagas themselves acknowledge. He was not entirely lying: the sheltered southwestern fjords where the Norse settled do have green summer pasture, which is why a farming colony survived there for over four centuries.

Iceland's naming is told with less certainty, but the common account credits a Norwegian settler named Flóki, who climbed a mountain after a hard winter, saw a fjord full of drift ice, and named the island accordingly before leaving. Iceland is green in summer across its lowlands because it sits in the path of the North Atlantic Current, an extension of the Gulf Stream, which keeps its coastal climate far milder than its latitude would suggest. Greenland is mostly covered by an ice sheet up to three kilometers thick because its interior is high, cold, and cut off from that warming influence.

Two footnotes. The Norse Greenland settlements collapsed in the fifteenth century, and the causes debated include a cooling climate during the Little Ice Age, overgrazing, declining trade, and conflict with the Thule ancestors of today's Greenlandic Inuit, who arrived from the west and were far better adapted to the environment. And the Greenland ice sheet holds enough water to raise global sea level by around seven meters if it melted entirely, which is why its accelerating ice loss is monitored closely and why the island is not a footnote in climate discussions.