In Australia, it seems, anything short of wrapping yourself in the national flag and singing a rousing chorus of `Waltzing Matilda' is regarded as surly bad manners.

Aussie joke first of all: "How do you know when a planeload of poms has just arrived?" "Because when the engine stops the whining continues." Apparently expatriate Brits get a lot of this kind of thing - largely, it seems, because anything short of wrapping yourself in the Australian flag and singing a rousing chorus of "Waltzing Matilda" is regarded as surly bad manners. In the early stages of Pommies (Channel 4), Brian Hill's engaging account of life Down Under, you could have concluded that Australians had all succumbed to a kind of cultural tinnitus - hearing a persistent needling drone where none actually existed. And that diagnosis appeared to be supported by scenes showing one of the poms shooting a commercial for the Australian Cheese Board, an advert which consisted of a smug farmer singing "Anything you can do, I can do better" to various indignant European peasants. Australian cheese is best served with chips on both shoulders, it seems.

After a while, though, you began to hear that whining noise yourself, particularly whenever Jackie and John Boyle were on screen. At one point Hill had interrupted this couple's long duet of disenchantment with a series of title cards reading "And another thing" - a teasing device which amplified the sense that they had turned themselves into connoisseurs of complaint. This wasn't entirely fair - they had just decided to trade in their waterfront house (complete with beautiful garden and swimming pool) for the dubious charms of Liverpool - so he had caught them at the very moment when they needed to shore up their nerve with a lists of God's Own bodges. That these sounded a bit strained - spiders in the garden, carcinomas in the sunshine, sharks in the sea - only added to the unavoidable pathos of their situation: not happy there but bound for discontent here. You left them at the airport, about to catch a plane back to the green, green grass of home. I hope future episodes include some account of how they feel after they've jumped the fence.

In stylistic terms, Scare Stories (BBC2), a series of programmes about the history of the environmental movement, is distinguished by passages of studied incompetence. You are introduced to new interviewees with sequences that suggest a chimpanzee has stolen a camcorder - the frame sways and lurches and occasionally swings away altogether to perform a cack-handed zoom on a pot of flowers. I couldn't detect any informative content to this infuriating indulgence; it was simply as if the director felt that her subjects need all the extra animation she could give them.

It is true that the subject matter is unlikely to lift the heart on its own - whatever you think about environmental issues they are more conventionally associated with guilt and anxiety than with pleasure. But so far the series has proved fascinating, charting the way in which the shrill alarm calls of the first activists have been disproved by events. In some cases this was because they had simply got things wrong; the one commodity that proved to be truly unsustainable was the conviction that doom was just around the corner (people had failed to realise that when commercial companies talked about "reserves" of particular commodities they were usually thinking of short-term operations - there was no market in prospecting for what you didn't yet need to dig up). The archive footage of those early days also confirmed the paradoxical duality of ecologists' attitude to mankind - an unusual mix of vanity (insignificant as we are, we can destroy a planet) and contempt (little allowance is made for our long history of solving problems as well as creating them). On the other hand, it isn't safe to dismiss current warnings. "We're in the business of self-defeating prophecy," said one pioneering ecologist in tones of wounded pride - properly reminding you that most of the Cassandras always wanted to be proved wrong.