It was all fearsome Nanny Wigley’s fault. When he was just a toddler, she used to make him go out barefoot into the Perthshire winter wearing only shorts and a shirt. Now, more than 40 years on, the world-renowned polar explorer, Pen Hadow, attributes his famed endurance of extreme cold to his harsh Scottish upbringing.

Without it, he says, he may not have survived some of his more dangerous encounters with the Arctic ice.

This Friday he is coming back to the land of his birth to talk about his extraordinary adventures to the Royal Scottish Geographical Society in Glasgow. He will also be sounding some dire warnings about the irretrievable damage being done to the planet by human pollution.

Before minding the wee Hadow at the manse in Glen Devon near Auchterarder in the 1960s, Enid Wigley had been nanny to Scott of the Antarctic’s son, Peter. To try and make sure Peter wouldn’t befall the same fate as his father, she had developed a “polar conditioning programme” which she later inflicted on Pen.

This only ceased when frostnip, a mild form of frostbite, was found to be freezing his extremities. But Nanny Wigley carried on filling the young boy’s head with exciting stories about Scott and other great explorers.

When he was just seven, he decided he had to test his powers of endurance by seeing how long he could hang upside down in an tree. Four hours later, his head swollen, he was forcibly removed by his horrified mother.

Now 48, Pen hasn’t lost his appetite for extreme exploits. He first shot to fame in May 2003 when he became the first person to complete a solo journey without back-up supplies or assistance from Canada to the North Pole.

The trek – Hadow’s third attempt in 15 years – took 64 days through temperatures down to as low as -46˚C. Several times it nearly cost him his life when he fell through thin ice and found himself submerged in the sub zero waters of the Arctic Ocean, hundreds of miles from any help.

He had to pull a 120kg sledge 480 miles across the ice, and swim through open patches of freezing water. He got so lonely, he says, that he started having conversations with his sledge.

His heroic feat, which has not since been repeated, is regarded as one of mankind’s most severe tests, at least equivalent to climbing Everest alone and without oxygen. Yet, within a year, Hadow achieved another first by walking unaided to the South Pole.

“It’s seriously, seriously tough when you do these expeditions,” he says. “For the first 20 or 30 days I’m on a knife-edge as to whether I feel I can go on or not.”

Not surprisingly, perhaps, his experiences have left him feeling passionate about fulfilling individual human potential. Less predictably, they have also made him increasingly anxious about the future of the planet.

This year, Hadow led a scientific expedition 450km across the Arctic to gauge ice cover in the northern part of the Beaufort Sea.

The expedition’s findings were frightening. They showed that the average thickness of the ice was only 1.8 metres, much thinner than scientists had thought, and not enough to survive the summer melt.

“Our evidence supports the emerging scientific consensus that we will have an 80% loss of sea ice cover in the summer within ten years, and a total seasonal loss in less than 20 years,” Hadow says.

“That means that for the first time in at least 40,000 years the white top of our world – its protective heat shield – is going to be a seasonal feature only.”

His findings have been presented to the UK climate change minister, Ed Miliband, as well as to Barack Obama’s advisers. And he will be delivering them to next week’s World Climate Summit in Copenhagen.

Hadow’s experience had convinced him that the natural world is being seriously stressed by pollution from human activities.

“The devil is in the detail of understanding how the natural world works,” he adds. “There has never been a greater need for people to go out there on their hands and knees to gather raw data.”

The environmental group, WWF, which helped back Hadow’s latest expedition, regards his evidence as crucial. “Pen and his team have shown that things are worse even than the most extreme predictions,” says Dr Richard Dixon, director of WWF Scotland.

“These reality checks are coming from all over the planet and we need world leaders to deliver a tough new deal in Copenhagen. That’s why this Saturday I’ll be joining thousands of people marching from Bellahouston Park in Glasgow for a safe climate.”