Mr Mear will set off on a 1,657-mile journey, starting at the Wendell Sea to cross the Antarctic, alone and unaided, towing a 450-pound sledge, his progress aided by a giant kite harnessing the wild winds.
If he succeeds, he will be the first man to do so. Thus it is no surprise to hear that a Norwegian, Borge Ousland, will set off a few days after Mr Mear with the same objective. It seems as if any Briton with a record- breaking goal in the lonely wastes of Antarctica finds a Norwegian dogging his steps (and overtaking them).
The continent has been crossed before. In February 1993, Ranulph Fiennes and Dr Michael Stroud made a 1,350-mile crossing before being airlifted out, suffering from frostbite and exhaustion. But it hasn't been crossed solo. "It is a race in the sense that once somebody has answered that question 'Can it be done?', it is not available to anybody else," Mr Mear said before departing. "But the excitement is about answering that bigger question - not about racing somebody else."
If it can be done, he certainly has the technical means to do it. His provisions include special high-energy biscuits made by Sainsbury's, to help to provide the daily 5,800 calories required. His tent will be black, to absorb any spare sunlight. He will wear a lightweight jacket.
And anyone who has access to the Internet can monitor his progress, thanks to a satellite transmitter in his pack. There will even be pictures: he will drop off video clips and photographs at the South Pole, to be transmitted and displayed on the Internet.
It is a far cry from the days of Captain Scott, who died in March 1912 along with his team on the return journey from their heartbreaking second place at the South Pole - beaten by Roald Amundsen's Norwegians. Scott had taken dining chairs, jam and biscuits. In Sir Ernest Shackleton's incredible epic of survival in the 1914/16 expedition to Antarctica, the ship Endurance was crushed by pack ice. The 28 crew were marooned for six months, first on an iceberg and then in three salvaged lifeboats. Amazingly, they all survived.
You cannot conceive the size of Antarctica; few of us can truly wrap our minds around the idea of covering any distance greater than a few miles on foot. When Mr Mear and Mr Ousland are separately traipsing over the undulating ice plains, they will focus on the world a few feet around them. It is a journey through monomania; only the very determined can even begin.
But why cross the Antarctic? It is as pointless a pursuit asclimbing any mountain, and quite possibly just as dangerous, given the staggeringly low temperatures (typically minus 15C, but down to minus 40C) and ice crevasses waiting to swallow the distracted or tired. Indeed, the great mountaineer Reinhold Messner has taken up such ice crossings as his latest challenge: he calls them "horizontal mountains".
Yet the technology surrounding this attempt seems to contradict its epic nature. If any spotty, overweight nerd can watch one man's battle against nature from the keyboard in the front room, can we really say that Roger Mear is in the wilderness? No, the journey he and Borge Ousland are really undertaking is one of the mind.
Which is all fine and good, but if it's such a private quest, why the big publicity fanfare? The fact is that these days you can't even start without sponsorship. Just setting foot on Antarctica incurs a fee. Mr Mear's expedition will cost pounds 94,888; so far pounds 75,820 has been raised. Sainsbury's has put up pounds 25,000 and Planet Online, an Internet company, pounds 10,000. And the modern quid pro quo of sponsorship is visibility. The Internet is the modern medium for telling your tale.
But that in turn leads to the question of whether Mr Mear will really be alone. Unsupported, certainly; and proud of it. But if the Internet's 30 million users are gazing over his shoulder as he slogs along, is it a personal adventure - or just more fodder for a world that turns any journey of the mind into a disposable video experience and chance for a quick marketing push?