Most 22-year-olds wouldn't let their dads anywhere near their diaries, but Sam Branson, on this count at least, doesn't fall into the category of "most 22-year-olds". Nor is his father your average dad; he's the multi-billionaire Virgin magnate so down with the kids he flew out to join his son for a stoning session on his gap year. He also happens to own a publishing company, so when Sam returned from a fact-finding expedition to the Arctic Circle earlier this year, which Branson Senior joined for a week, he showed the diary he had kept of the experience to his father. Today, the book of the diary hits the shops and Branson hopes it will raise awareness of environmental issues among young people. "There's nothing too scientific," he says. "Just my experience of the Arctic."
Sam Branson's tale of his month in the Arctic is eye-opening and simply told. He blagged the place on Arctic explorer Will Steger's Global Warming 101 expedition through his father, joining the professionals for the final few weeks of their 1,200-mile, four-month trek across Baffin Island. Branson says he was aware of climate change before the trip but was no expert. " It was more about going to the Arctic on this amazing expedition, learning about global warming and seeing its effects first-hand, seeing the Inuit culture and experiencing their way of life," he explains.
Back in April, after flying into temperatures of -10C in the town of Iqaluit, Branson immediately bumped into Jeremy Clarkson, who was embarking on the much less conscientious adventure of a race to the North Pole in a Toyota pick-up for Top Gear. The next day, edging closer to the expedition's starting line, he flew over the Barnes Ice Cap, a precious relic from the last Ice Age, which has been retreating since the 1960s and is a focus of the trip. "Like icing on a large cake," he records in his diary of this first peek at the immense glacier.
He lands at the 800-strong community of Clyde River, which became a permanent settlement in the 1920s when the Canadian Hudson River Company arrived to take control of the trade in fox pelts and seal skins, gathering Inuit families from far and wide to live in the town and support the industry. The fur traders are long gone, but the Inuit people continue to live between two worlds, and the surrounding area is home to caribou, ringed seals, narwhals and polar bears. It is here Branson gets his crash course in surviving at sub-zero temperatures, controlling the dogs who will pull his sled and weeing in a bottle in the middle of the night.
Branson Senior arrives a few days later and from here on it's heads down for long days sledding across the ice. "Going from the sea up the frozen river was like being in a fairy tale," he remembers. The team, which includes three Inuit hunters, rise at 6am each day and melt the ice cloaking their tents and sleds before getting on the road as quickly as possible.
The high jinks of careering across Baffin Island with his father, well known for his hot-air-ballooning exploits, are tempered by the dangerous conditions the team are travelling in. They are seven or eight days away from their destination of Iglulik when his sled nearly breaks through the ice of the MacDonald River. He makes a narrow escape, only to turn round and see the team mates behind him crash through the thinning ice. They pull them out with the dogs' help but Will Steger, whose almost unmatched experience in these climes includes an eight-month trip across Antarctica, is nonplussed that most of his gear is soaked through.
Branson's father and cousin Otto, a film-maker also on the tour, leave that day – Branson Senior to announce he is to build Virgin America, a new airline network across the US – and he continues alone.
A few nights later, at 2.30am, he is awoken by the sound of the dogs barking wildly and a shout of "polar bear". You don't cry wolf over this great white beast, and everyone was up and out of their tents immediately. "It was the size of a truck, but it looked pretty cuddly," says Branson. As the bear pads closer, undaunted by the warning shots which are fired, the whole scene is bathed in a lovely half-light as the last of the sun drops away. It doesn't run away until the Inuit hunters run at it, firing live shots all around its body. Both the thin ice and the light night air are symptoms of climate change.
Branson is equally struck by the people he meets as by the magnificent white wilderness. In a tiny coastal village where the snowy covering has been blown off the rocks and ice, an Inuit hunter says, "The world is slowly disintegrating. They call it climate change. But we just call it breaking up. " In the towns of Iqaluit and Iglulik he sees the challenges facing Inuit as they come of age. "They're living between modern and ancient times," he says. "They lived in igloos until the Sixties and now they're in wooden houses with TVs showing MTV. Because they're doing the traditional things less and less, there is not much to do, which is why the suicide rate is quite high. They're losing their identity."
If the young Inuit Branson meets are caught between two worlds which they can't quite bridge, he inhabits another dimension: his childhood was split between the family's private Caribbean island, Necker, and luxurious homes in Oxfordshire and London. His 21st birthday party last year reportedly cost £150,000. Yet with every opportunity available to him, Branson seems to be struggling to find his own berth, especially within the Virgin juggernaut, which his father is keen for him to join. After A-levels and a gap year backpacking, he dropped out of university after a month and took a cookery course. He should have made more of the course, he reflects, or perhaps learnt to cook more everyday nosh. He also models and is currently taking a three-month music course in Los Angeles: he plays guitar and would love for it to develop into a career, but isn't relying on it. Next year he will return to the Arctic with Will Steger and five other "emerging leaders" (Steger's term; Branson shrugs off its implications) to take part in an expedition across Ellesmere Island and monitor the collapsing ice shelves, before working on an eco-safari project in Kenya's Masai Mara, with Virgin.
It is no surprise to find Branson rather more eloquent on the Arctic than other issues around climate change, such as the damage done by the CO2 emissions emitted by planes and trains, many of them owned by his father. So accustomed is he to this apparent contradiction that he raises it himself. "If Virgin stopped flying planes," he explains, "BA or someone else would take their place. At least Virgin is investing 100 per cent of the profit into clean fuels and technologies to try and make it viable for planes to fly on clean fuel. Hopefully in the future we'll be able to fly without guilt."
Wishful thinking, probably, but Branson Senior has pledged $25m (£12m) to anyone who can come up with a way to remove carbon dioxide from the earth's atmosphere, and is reinvesting all the profits from his plane and train companies, an estimated $3bn (£1.45m), in biofuels over the next decade.
Branson's next Arctic adventure will follow in the footsteps of previous explorers, going through their diaries, and observing the changes that have occurred since the original notes were taken. Maybe Branson will find his niche in this explorer-storyteller role, but right now he is uncomfortable with the words "greenie" and "eco-warrior".
Warning signs: Climate change in the Arctic
* The weather in polar regions is changing more rapidly than elsewhere on the earth and may provide clues to what we can expect in years to come.
* The average annual temperature in the Arctic has increased by about 1C over the last century, which is twice the rate of temperature increase around the rest of the world.
* In winter the Arctic is hotting up even more quickly, and temperatures have increased by 2C over the past 100 years.
* These temperature rises have led to the thinning and retreating of sea ice and the thawing of permafrost. Across the entire Arctic Ocean basin, sea ice has thinned by 40% and its area is retreating by about 3 per cent per decade.
* The ice covering rivers and lakes has been freezing later in the year and thawing earlier.
* These changes delay and shorten the hunting seasons and more rain and fog is beginning to affect the drying season, when traditional foods are air-dried and stored for several months.
* The lack of ice can mean newborn seal and walrus pups do not have time to wean properly and will not survive.
* The sea ice serves as a seasonal migration route for polar bear and Arctic island caribou, and its changing pattern makes it more difficult for them to migrate and may lead to significant population decline.
Source: UCS; www.ucsusa.org
Arctic Diary - Surviving on Thin Ice is published by Virgin Books, £7.99