TV reviews: All Creatures Great and Small (Channel 5), Frozen Planet II (BBC1), Am I Being Unreasonable? (BBC1)

The third series of the rebooted All Creatures Great and Small (Channel 5) – putting further distance between it and the original, although not erasing the memory of Robert Hardy, Christopher Timothy, etc – opens with a poster on a wall: “For King and country.”

It’s 1939 and war is coming. James Herriot, now played by Nicholas Ralph, wonders as a Spitfire zooms overhead if he should be enlisting.

Vets are exempt, but James is James. “I have never known anyone with more passion and dedication to animals,” says Siegfried Farnon. He’s getting married in a few hours but, with a local farm threatened by a TB outbreak, James continues to be James. “His sense of duty will be the death of him,” says Tristan.

Tristan’s duty as best man is not to lose the ring. How do you think that goes? Entrusting him with a loaded shotgun would be less risky (he’s given one of them, too).

All the traditional tiny dramas of a TV wedding are in place. But it hardly matters that we know them so well, not this week anyway, and really not at all when a show is this charming, the characters this decent, the stories this heart-warming.

How, you might think, is it possible to love All Creatures Great and Small and at the same time love the non-charming Succession, the indecent Euphoria and the heart-chilling Industry (back on our screens soon)? Well, it just is. Sometimes I want a cup of (Yorkshire) tea, other times straight absinthe.

All Creatures Great and Small is returning us to a period in history much on our minds, when a nation would re-emerge from bomb shelters and greet a new young queen.

The sun-dappled hills are, of course, Yorkshire, known as God’s own country, although Ralph, a Highlander, might suggest the title could be shared around. And those who were glimpsing Royal Deeside for the first time, as Elizabeth II’s coffin began the journey south from Balmoral, might agree with him.

Attenborough, the true guardian of all creatures great and small, brings comfort and reassurance with his presence, although not in the message of Frozen Planet II (BBC1), a sequel to the original snow-capped blockbuster of 2011.

The problem, of course, is that nowhere is as snow-capped as it once was.

“Greenland is losing its ice six times faster than 30 years ago,” Attenborough tells us.

Put another way: “The Arctic is now warming more than twice as fast as the rest of the world.” The latter stat comes as a flimsy floe collapses under a polar bear, the hoped-for dinner of bearded seal slipping easily away.

This hungry beast, with even hungrier cubs, must remember how forefathers promoted Fox’s Glacier Mints atop a sturdy chunk of ice and she must weep.

The first episode journeys from North Pole to South. Along the way, assures our guide, we’ll “witness new wonders while there’s still time to save them”.

First up, though, those emperor penguins look vaguely familiar. That hurried waddle, fins pushed back, white chests puffed out – it could be Boris Johnson leading the Bullingdon Club in their tailcoats on another merry vandalism spree. (One day soon perhaps we’ll all feel less inclined to make Boris analogies; they’ll become extinct).

The programme is a veritable blizzard of numbers. Those penguins, down in Antarctica, the coldest place on earth, -80C, might have to waddle as far as 30 miles to reach to the sea.

Most relate to food demands with, for instance, the Pallas’s cat of the snowbound Gobi desert needing to consume five voles a day. This is a new wonder. I’ve never seen one of these ridiculously furry moggies before – the furriest in the world, says Attenborough, and the grumpiest.

The grizzly bear terrorising a herd of musk oxen effortlessly achieves his five-a-day – cute calves, too young to discern between friend and foe, tottering to their doom. Mums and dads watching with small children, this is the X-rated section, the one to be fast-forwarded.

But Frozen Planet II is incredible television, and the advances achieved by racer drones and other whojummyflipperies are a reminder of just how long Attenborough has been at this game.

Back in the days of clunky monochrome we would have missed the evil red eye of the killer whale, bobbing up from the deep behind a resting Weddell seal to assess attack options.

Also the expandable sack – red, too – within the left nostril of the hooded seal, which is used to attract the female of the species, a ruthlessly demanding creature for whom size appears to be everything.

Daisy May Cooper from This Country and Selin Hizli, having both come out of long-term relationships as mothers, have pooled ideas for the comedy Am I Being Unreasonable? (BBC1), which draws its title from the most overused phrase on parenting website Mumsnet.

There are echoes of Motherland, but while that show revolves around a gaggle from the school-gates, Nic (Cooper) has been dropping off her son for five years without making a single friend. Enter, the simpatico Jen for a good bitch and much booze.

But do Jen and Nic’s partner, in the biblical sense, know each other?