Love in a cold climate

The opening episode generated the requisite amount of wonder as it hopped between the north and south of the planet, one minute marvelling at a lake of melt water in Greenland which was the turquoise of swimming pools and the next giving us a glimpse of lava within snow-covered Mount Erabus, the worlds southernmost volcano. Gorgeous time lapse photography sequences showed icicles forming and melting and the flow of glaciers, pushing rocks ahead of them like pebbles. We saw a male polar bear searching for a mate and, having found her, fighting to keep his rivals at bay. By the time they finally got down to making some baby polar bears his fur was stained red with blood. He looked pretty relieved when the act was over and the couple went their separate ways.