CNN) -- It could be the ultimate test of human endurance: Three British explorers are risking their lives in subzero temperatures to measure the melting Arctic ice cap.
The team is on a three-month, 621-mile (1,000-kilometer) hike to their final destination at the North Pole. Along the way, taking precise measurements to determine exactly how fast the ice cap is disappearing.
"It's extremely difficult to live out here. It's very, very easy to get cold injuries in seconds," said Martin Hartley, team photographer and filmmaker, via satellite phone.
The team has been braving temperatures as low as minus 40 degrees Fahrenheit/Celsius spending their nights sleeping in tents and their days trudging across the shifting, barren polar expanse.
"The other day, we had to move the tent first thing in the morning because where we were camped, the sheet of ice was breaking up into dozens of pieces because of a tidal swell or wind in the ocean," Hartley said.
The unique expedition was prompted by this chilling prospect: The Arctic ice cap is melting at an unprecedented rate, which may lead to a dramatic shift in average global temperatures.
"In 2007, sea ice loss was the worst in recorded history," said oceanographer Kate Moran, professor of oceanography and ocean engineering at the University of Rhode Island.
The last time that scientists can say confidently that the Arctic was free of summertime ice was 125,000 years ago, according to the Web site of the National Snow and Ice Data Center in Boulder, Colorado.
All that could vanish within our lifetime, warn climate scientists, who predict that the Arctic sea ice in the summer season could be gone between 2013 and 2040.
Battling the daily grind of the brutal Arctic terrain, explorers Pen Hadow, 46; Ann Daniels, 44; and Hartley, 40, are in the second week of their 100-day journey to the top of the world.
Team battles Arctic winter to measure melting ice caps - CNN.com
The team is on a three-month, 621-mile (1,000-kilometer) hike to their final destination at the North Pole. Along the way, taking precise measurements to determine exactly how fast the ice cap is disappearing.
"It's extremely difficult to live out here. It's very, very easy to get cold injuries in seconds," said Martin Hartley, team photographer and filmmaker, via satellite phone.
The team has been braving temperatures as low as minus 40 degrees Fahrenheit/Celsius spending their nights sleeping in tents and their days trudging across the shifting, barren polar expanse.
"The other day, we had to move the tent first thing in the morning because where we were camped, the sheet of ice was breaking up into dozens of pieces because of a tidal swell or wind in the ocean," Hartley said.
The unique expedition was prompted by this chilling prospect: The Arctic ice cap is melting at an unprecedented rate, which may lead to a dramatic shift in average global temperatures.
"In 2007, sea ice loss was the worst in recorded history," said oceanographer Kate Moran, professor of oceanography and ocean engineering at the University of Rhode Island.
The last time that scientists can say confidently that the Arctic was free of summertime ice was 125,000 years ago, according to the Web site of the National Snow and Ice Data Center in Boulder, Colorado.
All that could vanish within our lifetime, warn climate scientists, who predict that the Arctic sea ice in the summer season could be gone between 2013 and 2040.
Battling the daily grind of the brutal Arctic terrain, explorers Pen Hadow, 46; Ann Daniels, 44; and Hartley, 40, are in the second week of their 100-day journey to the top of the world.
Team battles Arctic winter to measure melting ice caps - CNN.com
