The Polar see-saw or Antarctic climate anomaly is the phenomenon that temperature changes in Antarctica are usually of the opposite sign to temperature changes elsewhere in the rest of the world.
The most likely explanation is that the snow and ice in Antarctica is so clean that its albedo is higher than the cloud cover. Thus increased cloudiness over Antarctica causes more sunlight to be absorbed, hence warms the air, whereas the reverse happens elsewhere. Also, the air there is largely isolated from the rest of the atmosphere by vortices in the ocean and air.