Don't Panic: the Truth About Population, BBC Two, review If you're more than 50 years old, you've lived through something incredible: a doubling of the world population. Ten thousand years ago, there were only 10 million humans on the planet; it took until 1800AD to reach our first billion. But by 1960, we managed our third billion, and in the mere half-century since then, we've added four more. In an eyeblink, in geological terms, humans have gone from being just another species of large ape to utter global ubiquity. This, understandably, has scared a lot of people. Back in the Sixties people were writing books with titles such as The Population Bomb and Famine 1975! America's Decision: Who Will Survive? and saying that the world is soon going to starve. For half a century, we've been telling ourselves that doom is coming, any minute now, just around the corner. Global population collapse has, so far, failed to materialise. But for how long? Rosling was an engaging host, who looked and sounded like a Fifties B-movie mad scientist, but had a good line in throwaway jokes ("I'm Hans Rosling, and I'm a statistician. No, no! Don't switch off!"). He presented this programme in the form of a lecture, with graphs and images swooping back and forth on a futuristic screen in front of him, not unlike the sci-fi movie Minority Report, interspersed with documentary-style sections from around the world. In an early one, we went to Bangladesh, where, in 1972, the average life expectancy was less than 50 and the average woman had more than seven children. Now, life expectancy is over 70, and the average woman has around 2.2 children. The family planning workers whose story Rosling followed are "the heroes of our time," he said, for making contraception available to poor women, thus helping to avert population disaster. The Bangladesh story is representative. Worldwide, we're shifting from short lives and big families to long lives and little ones. Fifty years ago, the average woman had five children; now, it's 2.5, barely enough to replace ourselves. This is happening everywhere, even Africa, which for a long time was stuck in a harder past. The population bomb has been defused. But, said Rosling, we don't realise that. The majority of Britons still think Bangladeshi women are firing out whole platoons of babies (he complains he'd have got more right answers if he'd asked chimpanzees rather than British graduates). It was a wise and thoroughly informative programme, filled with surprising statistics, but mainly, it was an optimistic one. We're fantastically gloomy about the world's chances, but, in fact, demographics are on our side. It's rare and lovely to see a documentary that tells us not to panic, for once.