1) "The Furnaces of the Earth" takes us on a tour of the hot-spots where you wouldn't think life would dare to venture: deep in the oceans where hot gases and minerals gush through cracks in the sea floor; on land where hot, toxic springs bubble up; volcanoes that kill everything in their path when they erupt.

2) "The Frozen World" looks at life in the polar regions and high up on mountains. A surprising number of animals have managed to adapt to the harsh conditions and thrive in the freezer. They use a variety of strategies, such as thick fur, feathers, blubber, antifreeze in the blood and hibernation.

3) "The Northern Forests" that used to cover vast areas of land in the Northern Hemisphere, now somewhat reduced, support some hardy populations. There are hordes of busy, breeding and feeding animals in the summer months. When winter comes some migrate to areas of gentler climate, some hibernate and others continue to scratch a living as best they can.

4) "Jungle" - girdling the planet is an area of steaming jungle, fabulously diverse, teaming with life from the floor to the canopy. David takes his life in his hands to film from the top of the canopy (dangling from ropes!) right down to the forest floor.

5) "The Seas of Grass" where rainfall isn't sufficient to sustain forests of trees but there's enough to water vast plains of grass. Great herds of herbivores are pursued relentlessly for miles by packs of dogs (hyenas, wolves, etc) or crept upto and pounced upon by cats (lions, cheetahs, etc). Smaller animals burrow.

6) "Baking Deserts" call for some extreme adaptations. Some plants and animals can store huge amounts of water when it's available, in preparation of long, dry periods. Under the cracked mud of dry lake beds, dormant fish and toads wait to be brought back to life by the next rain, to breed and feed and then to sleep again. Just amazing.

7) "The Sky Above" provides David with the excuse for some 'fairground' fun discovering how some animals defy gravity? In a special plane he experiences the zero gravity sensation of weightlessness. Then he rises to the edge of the biosphere in a balloon to see what life is up there.

8) "Sweet Fresh Water" makes up only about 3% of the world's water - the rest is salty. Even so, an enormous variety of life is concentrated in our rivers, lakes and ponds. Small, isolated bodies of water harbour small, isolated, unique species of plants and animals. Rivers teem with life.

9) "The Margins of the Land" are constantly shifting as the sea erodes cliffs, sweeps away sand and shingle and deposit the dislodged material further up the coast. Mangroves hold onto their soil and help the land to advance. The margins can be hard areas to make a living but many try and succeed.

10) "Worlds Apart" is about island life. Diversity goes extreme as animals adapt to island conditions in isolation. And it's not just that the rate of speciation is high - species tend to get large on islands, like the giant tortoises, Komodo dragons and large flightless birds (remember that unfortunate relative of the pigeon, the dodo).

11) "The Open Ocean" Most of the surface of the planet is covered by ocean yet it's our least explored environment. It harbours an incredible amount of life, swarming in the sun-lit upper regions but sparse, mysterious and strange in the depths.

12) "New Worlds" brings us up to date with human environments. Even though city scapes look unpromising places for animals to live, many have managed it. Rats and cockroaches have done very well of course, but also pigeons, some hawks, foxes, racoons and so on. Other species have not adapted to or benefited in any way from human alterations to the environment. David suggest that we should be more conscious and careful in the future about how we use and abuse our environment so that we hang on to the biodiversity and beauty that still remains.

Fascinating as usual. David Attenborough and his team never put a foot wrong. Anyone who's interested in our planet will enjoy this.