While sea ice in the Arctic has shrunk remarkably over the past few decades, sea ice around Antarctica has been dancing to the beat of a different drum. You might expect that as the world warms, sea ice would dwindle no matter which end of the planet it’s on, but the two regions are quite different.

While the North Pole sits in an ocean surrounded by land, the South Pole is in a continent surrounded by water. Antarctic sea ice grows outward from the coast, aided by the isolating winds that encircle the continent and carry frigid, inland air that pushes the ice around. So even as warmer water reaches under the floating ice shelves of Antarctica’s glaciers, persistently eating away at them, the growth of winter sea ice is more closely tied to wind patterns.

Climate models project a big decline in Arctic sea ice, with the end of summer becoming essentially sea-ice-free within a few decades at the current rate of warming. But in Antarctica, the models project smaller long-term declines.