Terra Nova, Sky1

Is it back from the future or forward to the past? We start in the year 2149, and Earth is overcrowded, polluted and staggering towards extinction. Nobody can breathe outdoors without using a rebreather mask, and most plant and animal life has withered away. Near-derelict tower blocks rot in the sickly ginger twilight, like out-takes from Blade Runner. 

By an amazing stroke of luck, scientists at the FERMI Particle Accelerator have discovered a fissure in the fabric of time (sheesh, not again), and they've used it to construct a gateway back to the primeval world that existed 85 million years earlier. Through this, carefully selected batches of humans are being transported back through time to start again from scratch by colonising the then-unblemished earth, which is rich in forests, rivers, jungles, blue skies and staggeringly fresh air. It's also rife with dinosaurs, both tall, sleepy-looking ones that eat vegetation (pictured below), and furious snarling ones with chainsaw teeth and whiplash tails that can cut an unsuspecting person in half. Everybody who's watched this programme has said how much it reminds them of Jurassic Park, and there's a chap called Spielberg listed as executive producer.

Nonetheless, there could be some mileage in it, and the budget is handsome enough to allow for a hefty dollop of CGI monsters and landscapes that sweep away into the distance. A shame, then, that they've gone and ruined it with a bunch of characters so flimsy that they're already curling at the edges like damp cardboard. This opening double episode briefly promised to be a provocative, and possibly even political, fable about the cynical and criminal squandering of the planet's resources, but that theme disappeared in the teeming prehistoric jungle.

For openers we met the Shannon family (pictured left), at home in their cramped apartment after another hard day of trying to force an adequate supply of air into their lungs. Domestic pleasantries were suddenly interrupted by a police raid, and the cops took mere seconds to discover the Shannons' five-year-old daughter Zoe in the air duct where her parents had hidden her. And why had they hidden her? Because the law stipulated that no family could have more than two children (quite generous actually, considering the planet's moribund state), and Zoe was the Shannons' third. Her father Jim (Jason O'Mara) started lashing out at the cops, which was a bit stupid because (a) he was a copper himself and (b) he'd broken the law and was bang to rights. Long story short, Jim went to jail and did not pass Go.

No matter. Several years rocketed past in nanoseconds, and Jim's doctor wife Elisabeth (Shelley Conn) was down at the mega-prison telling him how she'd been chosen to go on the 10th Pilgrimage to the World of Dinosaurs. Next thing you knew he was busting out with the help of a pocket laser and jumping the queue for the time warp. Fortunately, Commander Nathaniel Taylor (Stephen Lang, who played the ruthless Colonel Quaritch in Avatar, another of Terra Nova's source texts) took a benign view of having a convicted felon among his primeval colonists. Or maybe it's just impossible to send people back once they've arrived (Stephen Lang, pictured right).

The rest of it was devoted to life in the late-Cretaceous period, intercutting close encounters with various snarling beasts with the alarmingly cosy domestic arrangements of the reunited Shannons. There are the blushing puppy-love antics of daughter Maddy, the passive-aggressive surliness of son Josh who hasn't forgiven dad for going away to prison and goes charging around the jungle with a bunch of rebellious kids, and mom's attempts to keep the atoms of her nuclear family orbiting under one roof. It's like Space Family Robinson meets The Flintstones, or a pre-Paleolithic Dawson's Creek. Looks like there's at least one outsized fly in the ointment, however, in the shape of the so-called "Sixes", a rival group of colonists who are at daggers drawn with Taylor's contingent. Not a terribly original idea, since they're just like the Others in Lost, but we're going to see a lot more of them.

Watch the trailer for Terra Nova