RADIO / Steel industry: Robert Hanks on the 'comedy of recognition' and the virtues of sustainability

Time was, novelty and originality were considered virtues; but that was before green politics made 'sustainability' desirable. Mark Steel clearly has sharp antennae for the Zeitgeist, since there are grounds for putting forward The Mark Steel Solution (Radio 4, Friday) as the first fully sustainable comedy programme.

Which is not to say that the jokes are all old (although the theme of last week's programme, transport, did make room for some much-loved quips about British Rail's unreliability). But the way the programme is constructed, it requires a tiny input of humour to keep going. For one thing, it relies largely on the 'comedy of recognition' - a term that begs for a second set of quotation marks (' 'comedy' of recognition'). Recognition comedy works on the belief that observing a phenomenon is funny in itself, and making jokes would be inartistic and cowardly. Sometimes it works well, as with Steel's imitation of the irritating 'digga digga digga' noise that stationary trains make; but it doesn't require actual invention.

The other ecologically notable feature about The Mark Steel Solution is that it makes its jokes last - about 10 average-to-good ones spread over half an hour. Because each good joke is stretched much farther than you'd have thought was practical, there's little room for bad ones. And at the end, there's an extended sequence in which almost every gag is recapped - it feels a bit like a test to see whether you were paying attention, but at least shows that the writers were thinking about what they were doing. All in all, it's quite good.

Meanwhile, the virtues of 'sustainability' have been the subject of hot debate in Radio 4's environmental magazine Costing the Earth (Wednesday). The main issue this week, the first edition of the series, was how the decline of the milk bottle has led to massive deforestation.

Increased paper carton use has led to massive tree-loss in British Columbia or - just as serious - replacement of natural mixed forests by artificially dense pine plantations where 'a deer has to pack a lunch'. One answer is to harvest wood from 'sustainable forests', supposedly the Scandinavian model (in fact, most of Sweden's 'sustainable' forests are grown from bought-in seedlings). The more radical answer is to cut down drastically on paper and cardboard, and start recycling like crazy.

A representative of a packaging company suggested that getting rid of cardboard packaging would lead to hygiene problems. Someone from the Women's Environmental Network told her she was talking nonsense. Mark Whittaker, the presenter, summed up the debate's outcome: 'Not a glimmer of compromise between the two of your, but I never thought there would be.'

If he didn't think the argument was going to get anywhere, the only point can have been the sheer vicious pleasure. And it's this (sadly uneven) cussed streak that makes Costing the Earth appealing. Compare the ingratiating 'Isn't ecology fun?' style of Dirty News (Radio 5), the weekly slot for environment news whacked incongruously into Diana Madill's The Magazine on Tuesdays. Last week's edition centred on the landlord of the isle of Eigg, who is in dispute with his tenants: according to the commentary, not only had he got Eigg on his face, but he was not Eigg-static. 'To find out more,' chortled the presenter, 'I went to work on Eigg.' Not that I want to encourage this sort of thing; but Dirty News leaves Rhum for improvement.