Iain Banks used to be a gas-guzzling high-flyer, zooming round Scotland for the nine months of the year when he wasn't writing a novel. Now he has gone eco-friendly - and anti-Blair, he tells Louise East.
On the face of it Iain Banks is an unlikely poster boy for the green lobby. In the 23 years since his first novel, The Wasp Factory, buzzed to the top of the bestseller list, countless newspaper articles have marvelled at Banks's have-your-cake-and-eat-it lifestyle. Cheerfully admitting to writing most of his novels in three months, Banks appeared to spend the other nine months of the year zooming round his native Scotland in his €250,000 collection of cars, which included two Porsches, a Jaguar, a BMW and a souped-up Land Rover. Between times he indulged a passion for malt whisky, won Celebrity Mastermind (specialist subject: malt whisky), played computer games and took flying lessons - which, to paraphrase Robin Williams on the subject of cocaine, may well have been God's way of saying he was making too much money.
But a couple of years ago cracks appeared in the hedonistic image. Banks believes it might have started when he replaced all the bulbs in his Fife home with energy-efficient ones. Or perhaps it was when he stopped flying after cutting up his passport in protest at the war in Iraq. (He popped the pieces in an envelope and sent them to Tony Blair.)
Last September, Banks went the whole hog and sold all his high-powered cars, replacing them with a more energy-efficient Lexus hybrid. He has also invested in a wind turbine for the roof of his house, and the publicity tour for his new novel, The Steep Approach to Garbadale, was dictated by Banks's insistence on keeping his carbon emissions low: a trip to Ireland had to be abandoned because the schedule was too tight for Banks to travel by ferry.
So what brought all this on?
"It would be a much better story if there was some road-to-Damascus conversion," he says cheerfully. "But really it was a cumulative thing. I was thinking about reducing the number of cars I owned, and I just thought I might as well bite the bullet."
Not everyone will be pleased. Jeremy Clarkson, the oil baron's friend, has already waded into the debate - "It's a shame Iain Banks has succumbed to the propaganda of the hippies and the communists" - and those suffering from green fatigue may dismiss Banks's gesture as a drop in the ocean.
"You could apply the same argument to voting," Banks points out with one of the Falstaffian laughs that punctuate every other sentence. "If people don't like the idea they can just regard me as selfish. Cutting down on the carbon I've pumped out over the years makes me feel better."
In truth, Banks has always been fiercely principled. As well as being critically acclaimed and commercially successful, his 21 novels - 12 mainstream, nine sci-fi - are suffused with the kind of left-leaning, uberliberal, anti-imperial politics for which student-union bars were invented. The Steep Approach to Garbadale, his first mainstream novel in five years, is already being touted as his best since 1992's The Crow Road (which was subsequently made into an award-winning television series).
Like that novel, it deals with a sprawling eccentric family with dark secrets to conceal, this time around the Wopulds, creators of a world- famous board game called Empire! Never one to resist a potshot across the Atlantic, Banks has his narrator describe how Empire! was a dead duck in the US until it was renamed Liberty!
"You've got to make your point in such a way that people don't want to throw your book across the room," he says. "If this novel is about anything, it's about one generation making a mistake and the next generation trying to cope with it or fix it."
The Steep Road to Garbadale also has more than a whiff of incest, which will come as no surprise to fans of The Wasp Factory, in which a serial- murdering teenager takes directions from a bottle of irate wasps. Such is Banks's predilection for the gothically weird and taboo that he has spent the past 23 years denying that he, personally, is a murdering, psychotic pervert. "There's still this bizarre lack of understanding about what it is to have ideas and be creative," he says. "Every now and then I find myself saying: 'Look. This is my job. I make things up that sound real but aren't. That's what I do.' "
As to why he chooses to cover such bleak territory, he has a theory that it's because he suffered that most artistically unfashionable of things: a happy childhood. "I was loved. Nothing bad or horribly traumatic ever happened to me. I think if really nasty things had happened, maybe I wouldn't be able to write about that sort of stuff," he says. "On the other hand, maybe I'd be a total genius."
Unusually for a man of 53, Banks's mum and dad are still alive (82 and 89 respectively), and, even more unusually, they live next door to him in the village where he grew up. Until recently Banks lived with his wife of many years, Annie, but the pair have separated. "The reason I gave up learning to fly, and the reason this book was six months late, was that my wife and I were splitting up. You really have to concentrate when you're learning to fly - they're kind of insistent about that - and you have to concentrate to write."
Drily describing the whole experience as "not great fun", Banks says: "These things are always traumatic. My instinct was to walk away, but I couldn't, because I couldn't abandon my ol' ma and pa. That was difficult." Banks finally split with his wife in September 2005. He is now with a new partner, Adele Hartley, the director of an Edinburgh horror-flick festival.
"I wrote this book in the first three months of last year, and it's definitely fuelled by the relief and release I felt." So is it true that he can turn out a novel in a quarter of a year? "Well," he says, "I think about it quite hard in the months before I start writing - probably only for half an hour a day, but it's quite intense."
Half an hour a day will hardly appease the naysayers - a point Banks is cheerfully aware of. "I should have just said: 'Oh yes, it's absolutely hellish, I tell you, sitting in my garret, sweating blood.' "
Nor has his candour always been rewarded. On publication of Dead Air, his post-9/11 novel, Banks made it known that he had written it in a mere six weeks. With relish, Banks takes up the tale. "Of course, people said: 'Imagine how much better it would be if you'd taken seven.' " He snorts with laughter.
For every book that Iain Banks writes, there's one written by his alter ego, Iain M (for Menzies) Banks. These are the sci-fi novels, many of them set in a futuristic society called the Culture, where poverty no longer exists, the powers-that-be are benign and androids specialise in sarcastic backchat.
"I'm a long-term optimist and a short-term pessimist," he says. "I really hope that in some distant time people will look back and think of these years as the dark ages when people still had disease and war and poverty."
Atypically for a member of the green lobby, Banks believes the answer to the world's problems lies not in retiring to the highlands to weave your own clothes but in ploughing more funds into technology. "One of the problems I have with a lot of people who are ostentatiously green is that they're quite short-sighted about technology and about space. We have to get into space. Even if the rockets do end up adding a bit more to global warming, we just have to bite that bullet and damn well do it.
"I really do hope that humanity's going to have a future in the stars and that the earth is just a cradle. My own personal preference would be for a galaxy that's already well filled with other life forms, because I find the idea of us taking our neuroses, stupidity and xenophobia to populate the galaxy slightly alarming."
If space travel takes off, of course, Banks may live to regret butchering his passport. The question is, did Blair ever write back? "Not personally, no," says Banks, bellowing with laughter. "A minion sent a receipt saying: 'Thank you for the bits of your passport.' Then, ironically, in 2004 I got an invitation to some reception thingy that Tony and Cherie were having, so I wrote a really sarcastic letter, saying: 'I'm the bolshie scribbler who sent his passport to you in pieces a year ago. Now that all the weapons of mass destruction have turned up and Iraq is profoundly at peace, I feel a complete idiot for taking my stupid moral stance, but, nonetheless, I won't be coming to your party.' "
So he isn't expecting his name to appear on the honours list any time soon? "No. Well. Actually . . . " He hesitates and, for the first time in the interview, looks vaguely embarrassed.
"Well," he says, before conceding in a rush: "Oh, hell, my mum is probably never going to read this, so, I was actually offered an OBE years ago. I was going to be Obe-Wan Banksy," he says forlornly. "But, no, I couldn't do it. The whole honours-list thing is just not me."
Passionate about his principles and worried about his mum: the green lobby is lucky to have him.
The Steep Approach to Garbadale is published by Little, Brown, £17.99 in UK