Activists become first to reach North Pole in summer
When they got there, the Pole was covered with water.
"What really surprised us was the state of the ocean," said Lonnie Dupre, 45, a carpenter from the Midwestern state of Minnesota. "We've seen the ocean bursting up under our feet," he said.
"We expected flat, condensed ice from about 86 degrees north but when we got here the ice was completely pressured and fractured everywhere."
The 700-mile (1,126 kilometer) trek was fraught with peril as the pair pulled their canoes through blinding fog that blurred the line between the earth and sky and over ice that cracked beneath their skis and shot up out of the water.
It was the morning before they reached the Pole that they encountered their first polar bear.
A young male had followed their ski tracks, staying downwind and hiding behind drifts before circling their camp in loops.
Eric Larsen, 35, woke to the sound of his footsteps outside their red tent at about 4 am. He grabbed a flare while Dupre grabbed a video camera. The bear lumbered off slowly and seemed more curious than aggressive.
"It was like the polar bear was coming by to say thank you for what you're doing," Dupre said.
"It was kind of symbolic."
Dupre and Larsen have been collecting samples of ice and snow to help scientists measure the degree to which the ice cap is retreating. Scientists are calling these measurements the Holy Grail of global warming data because no one has ever taken accurate measurements of the Arctic ice during the summer.
Satellite images are difficult to obtain during the summer months because the region is covered in fog.
"The Arctic Ocean is busting up and it's busting up quickly so we have to get on the bandwagon about global warming," he said, noting that the United States has just six percent of the world's population but creates 36 percent of the greenhouse gasses and consumes 36 percent of the world's resources.
"The Arctic Ocean could be free of ice (in summer) by 2050 which means the polar bear could be extinct."