It was, as the criticism went, all style and no substance; pretty pictures of nature at its rawest but serving little purpose beyond that.

However, the latest instalment of the series (Sunday, 9pm, BBC1), which took four years to film in some of the world’s most inhospitable environments, answers the criticism with coverage of Arctic and Antarctic wildlife and their struggle for survival as their natural habitat becomes unrecognisable as the planet warms.

Polar bears find their traditional hunting ground eroded and are forced to swim 60km or more in search of land and food.

For the most part, series narrator Sir David Attenborough lets the pictures do the talking as far as climate change is concerned and his hypnotic commentary regales us with a phenomenal amount of information concerning the lives of the featured creatures.

For example; did you know that it is the male emperor penguins who are responsible for incubating the eggs containing their offspring?

Following a brief mating, the female passes the egg to her mate before heading off elsewhere.

As the temperatures drop and the dark Antarctic winter descends, thousands of males are forced to huddle tightly together in order to provide enough warmth for the eggs to be sufficiently incubated so the future of the species can be safeguarded.

The nearest human males get to such closeness is after eight pints of Stella when they suddenly experience unprecedented security in their sexuality, sling an arm round a complete stranger and slur, “I love you, you know. No, no listen — I may be drunk, but I’m telling you — you’re my best mate and I love you”.

At least the penguins aren’t likely to wake up in the morning with a feeling of great remorse thinking “Uuuurgh, did I really tell that weird penguin from Queen Maud Land I loved him? Oh no, we’re supposed to be going paintballing sometime. Jeez, never again”.

As the winter passes, the chicks hatch just in time for the females to return, bringing with them plentiful supplies of fish and squid and the parents are reunited.

It is at this point the father is supposed to pass the chick on to the mother to keep warm in her pouch but many were reluctant to do so. To the point where you felt some might join Fathers4Justice if they were refused custody and would take to the roof of Buck House dressed as a superhero to draw attention to their plight (The Penguin dressed as Batman? What kind of sick double-cross is he trying to pull? Hopefully Robin is alert to this elaborate ruse).

The world is a cruel place though and many of the chicks don’t make it.

The urge to parent is incredibly strong amongst emperor penguins and many bereaved mothers act like Madonna in a Malawian orphanage as they fight over parentless chicks to adopt.

Planet Earth is full of tears, laughter, cuteness, tragedy and harsh reality and as such it, like Natural World (Wednesday, 8pm, BBC2), is unmissable for anyone who looks reverentially and wondrously upon a world that us laymen know very little about.