Arctic explorers prepare to leave for climate survey expeditionPen Hadow and his team are embarking on a three-month Arctic expedition that will see them endure temperatures as low as -90C, drag sleds of up to 120kg and face threats including polar bears attacks
Link to this videoThree British explorers hope to set off tomorrow to trek and swim more than 1,000 km across ice pans, frozen ridges and open ocean to help scientists discover how long it will be before the Arctic sea ice disappears due to climate change.
Pen Hadow, Martin Hartley and Ann Daniels plan to fly six hours north from their base at Resolute in northern Canada to a point at the edge of the year-round sea ice and from there set off with sledges laden with measuring equipment to take at least 10m readings of the density and thickness of the frozen sea water beneath their feet.
Speaking to the Guardian from Resolute today , on his 47th birthday, Hadow said: "We've been planning this for five years, so we're hugely excited, but equally we'd be mad to not be anxious. The first few weeks are so extreme. We're going into one of the most extreme environments on the planet with very little protection: we're just out there in the clothes we stand up in, we have barely got any supplies."
In an exclusive video for the Guardian from a rehearsal expedition near the team's Canadian base, Pen Hadow said that preparations had gone well. "The weather's been pretty harsh until today and we've had some time out and about doing some final tests for our pioneering technology."
The planned departure of the £3m Catlin Arctic Survey though is far from certain, because a storm is moving towards the team's drop off point on the sea ice. Hadow said it was "75% likely" they would set off tomorrow.
The expedition was prompted by mounting concern over large declines in the Arctic sea ice area, which the National Snow and Ice Data Centre in the US calculates is, on average, declining by an area the size of Scotland every year, raising fears about a spiralling cycle of warming and melting as the darker exposed ocean heats up, exacerbating global climate change.
The losses have prompted experts to bring forward forecasts for when the summer sea ice will disappear from a century to about 30 years, and in one case as little as four years. However experts at the UK's Met Office have cautioned against over-gloomy warnings, saying it is too soon to say how much of the recent more dramatic losses were due to natural variability.
The survey will take automatic radar soundings of the depth and density of ice pans, and stop to make regular cores for more detailed measurements of the ice and sea water below, in an attempt to help experts be more certain of not just the area of ice but the total volume of frozen water, four fifths of which is below sea level, said Hadow.
Hartley, an award-winning photographer, will take photographs and video, and the team will carry a voice recorder for their visual impressions of the landscape. The results, which will be fed back to scientists in the UK and US by satellite, will be used to test and improve models, and could also help calibrate satellite measurements which have been collected for 30 years.
"At a global scale we need to understand how our planet works, particularly this early warning system which is the sea ice in the north pole region," said Hadow. "Never has that been more urgently needed, and the only people with the skills and experience and the commitment to the rigours are sea ice/polar explorers."
During the up to three month expedition they will drag sleds weighing up to 120kg and endure temperatures that with the wind-chill factor could dip as low as -90C. There will be the constant threat of falling through the ice, polar bear attacks, sudden illness, accidents with the sleds on often rough and steep ground, and carbon monoxide poisoning from the small stoves they use to melt ice and heat food in their tent at night. They each expect to lose a significant amount of weight as they cannot carry enough food to compensate for the hard work.
In 2003, Hadow became the first known human to trek solo and unaided by resupply planes from Canada to the north pole at 90 degrees north. This time the team will have resupplies, though these have had to be cut back because of difficulties raising the last bit of sponsorship and the falling value of the pound.
As well as insurance giant Catlin, expedition supporters include the United Nations Environment Program, the Prince of Wales and conservation charity WWF.
• You can follow Hadow and his team's expedition via the Guardian's environment website with regular pictures and video from the ice and blogs from the explorers. There is also more information on the Catlin Arctic Survey website
