Some of the most dramatic signs of climate change are taking place in the vast and frigid polar caps, where relatively few humans live. We would know much less about them than we do but for recent advances in satellite technology and remote sensing.

A European Space Agency satellite scheduled for launch April 8 promises to add to the growing body of scientific knowledge, based on observable facts, about the way in which rising surface temperatures are interacting with ice and ocean in the north and south polar regions, raising sea levels around the world.

The ESA satellite is due to be carried into polar orbit about 700 km above Earth on a rocket from the Baikonur Cosmodrome in Kazakhstan. It will carry an advanced all-weather microwave radar altimeter. This sensor is specially configured to measure changes in the elevation, and thus the thickness, of ice on land and floating on the sea.