Hang on for dear life - but sometimes, you've just got to let go...

The warm Leicestershire voice on the phone has turned business-like. "OK, I'll give you a few minutes on this and that's it." The voice belongs to Simon Yates, the British mountaineer who, in 1985, fell into the public consciousness when he and his climbing partner, Joe Simpson, made an epic descent of the Siula Grande peak in the Peruvian Andes.

"I've been interviewed by lots of journalists on a range of climbing subjects," says Yates, 38, "and all they ever write about is what happened with Joe." Aware that "what happened with Joe" introduced him to a global audience, far beyond the attention of the specialist climbing press, Yates agrees that any article about him would be incomplete without refreshing the public's memory of "that incident". So let's get it over with.

Near the summit of Siula Grande – 21,000ft (6,400m) – Simpson took a heavy fall, shattering his right leg. Yates knew Simpson's chances of getting off the mountain were slim, yet against the odds and roped together, they battled through a snowstorm. They had reached 3,000ft when Simpson slipped off an edge. Suspended six feet from the ice wall, Simpson was unable to climb up, and Yates realised he could not reach his friend. As Simpson's weight threatened to pull them both from the rock face, Yates took the only option he had: he cut the rope. Back at base camp three days later, Yates began to pack up, knowing he had consigned his friend to death. As he turned to leave, a figure crawled towards the camp. It was Joe Simpson.

Simpson's account of his escape, Touching the Void, became an international bestseller. In it, he acknowledges that Yates made the best decision he could under the worst circumstances (they are still in touch). But I've called today to get Yates's perspective on Yates, and in particular, to discuss his new autobiography, Flame of Adventure.

He hopes the book will eventually take its place in what he calls "the great British tradition of mountaineering literature," a heritage that owes its success to the general public's "morbid fascination" with the risky nature of mountain sports.

"I can remember a few years back when a gang of journalists would decamp to Fort William [in Scotland] every winter and wait for climbers to start falling off Ben Nevis," he says. More often than not, some hapless tourist obliged. It is this prospect of sudden death that "keeps the public interested and sells newspapers".

Travelling to some of the remotest parts of the planet to climb, Yates has had time to reflect on the reasons he does what he does, and his conclusions offer a refreshing departure from the glib mountaineer's mantra; "Because it's there".

"I climb for the adventure and I wanted to write the book to try to express something of that spirit." It becomes clear during our conversation that keeping the flame of adventure alive is something of a personal crusade for Yates, who runs his own adventure travel company when he's not climbing. "We live in a society in which most people expect to live to 70 or 80, and if something interrupts that then it's someone else's fault." For a straight-talking Leicestershire lad, Yates is not without his philosophical side.

"Living in an urban environment, most people work in providing services that are based on wants rather than needs, and are quite happy to believe that living life without risk is perfectly natural.

"I would argue that the opposite is true and for me, climbing is about getting back to a natural state. It's easy to see how hunting or fishing, as sports, are based on our needs, or instincts, and I spent a long time thinking that, in that sense, climbing was rather obscure and pointless.

"But mankind began life in the East African Rift Valley. Without some bright spark saying 'What's that over there? Let's have a look,' we might never have developed as we have."

Going and having a look, Yates has found himself at the top of some of the highest mountains in the world – among his achievements are a first ascent of Leyla Peak (20,650ft) in the Pakistani Karakoram, and a first British ascent of Khan Tengri (22,950ft) in Kazakhstan.

Yates admits he found writing Flame of Adventure "a bit like homework". Much to his credit, the book avoids any trite confession to a tortured youth from which climbing provided an escape. Instead, Yates chooses instead to describe his early climbing forays around Chamonix in the French Alps. He tells how "partnerships were usually forged around a stove or camp fire, after several bottles of shared cheap wine". Entrusting your life to someone you hardly know sounds like a recipe for disaster, but Yates is quick to contradict me.

"You get to know of climbers by their reputations and you look for personalities that complement one another. I think it's quite a noble way to choose a team." He says it as if speaking of some long-demised code of honour.

Which brings us back to "that incident". In cutting the rope, did he break a climbing taboo? "I suppose some older climbers thought I might have done; and looking back with more experience, I might have done things differently. But we were young and it was the first time on a big mountain for both of us. We were learning," he says thoughtfully. "When you climb, you are always learning."

'Flame of Adventure' (Jonathan Cape) is is available now, £16.99