IQALUIT, Nunavut - Inuit hunters are falling through thinning ice and dying. Dolphins are being spotted for the first time. There's not enough snow to build igloos for shelter during hunts.

As scientists work to establish the impact of global warming, explorers and hunters slogging across northern Canada and the Arctic ice cap on sled and foot are describing the realities they see on the ground. Three of them recently spoke to The Associated Press.

"This is really ground zero for global warming," said Will Steger, a 62-year-old Minnesotan who has been traveling the region for 43 years and has witnessed the impact of warming on the 155,000 indigenous people of the Arctic.

"This is where a culture has lived for 5,000 years, relying on a very delicate, interconnected ecosystem and, one by one, small pegs of that ecosystem are being pulled out," Steger said by satellite phone from a small village outside Iqaluit, about 200 miles south of the Arctic Circle. Iqaluit is the provincial capital of the Canadian territory of Nunavut.

Steger, who made the first journey to the North Pole by dogsled without resupply in 1986, is sledding with Inuit guides for three months across Baffin Island, the northeastern corner of Nunavut, with two teams of huskies and a cameraman.

He is charting his 1,200-mile adventure on his Web site, and making a documentary about how Inuit hunters are being forced to adapt to a warming Arctic Ocean and melting polar ice cap. In June, he will testify before a U.S. Senate committee on climate change.

When he was interviewed in early March, he and his American and Inuit colleagues were heading for the Clyde River, through the highest polar bear population in the world. It was still the height of winter in the Arctic, but the temperature, 11 degrees Fahrenheit, was more typical of spring.

He said hunters he meets on Baffin Island are describing to him creatures they have no words for in their language, Inuktitut -- robins, finches and dolphins. He said they all tell him the same thing: Hunting on the thinning sea ice has become too dangerous.

"All of these villages have lost people on the ice," Steger said. "When you have a small village of 300 or 400 people, losing three or four of their senior hunters, it's a big loss."

Millennia of learning to read the winds, clouds and stars and find the best hunting are being lost, he said. "A lot of the elders will no longer go out on the sea ice because their knowledge will not work anymore. What they've learned and passed on for 5,000 years is no longer functional," Steger said. "They can't build igloos anymore; everything is just upside down up here."

Meeka Mike says the thinning of the ice became noticeable about 10 years ago, forcing Arctic animals to migrate farther north.

Now Inuit hunters like herself are finding stranded walrus and seal pups left to die on floating ice.

"It takes longer now to get out to our hunting areas because we can't access it by ice," Mike says in her cedar house in Iqaluit, sitting on the floor with friends as they sew a pair of caribou hunting pants she'll wear when she next ferries supplies by snowmobile and wooden sled to Steger's expedition.

"The ice freezes much later and therefore it's thinner and breaks off during the full-moon tide," she says, pointing out to Frobisher Bay, a massive inlet of the Labrador Sea on the southeastern corner of Baffin Island.

To an outsider, the bay in midwinter looks ice covered with wisps of vanilla icing. But Mike says hunters can see the bay rise and fall with the tide.

Life, she says, is "very much out of sync."

She blames Americans for emitting one-fourth of the world's greenhouse gases which scientists say are very likely causing the warming. But it is not in the Inuit culture to be too accusatory, and she says it with a smile: "Unfortunately, you are the people who cause most of this climate change," she says to an American journalist.

Farther north is Rosie Stancer, a 47-year-old mother and distant relative of the British royal family. She set off alone on March 6 for a 60-day journey across 475 miles of the frozen Arctic Ocean to reach the North Pole, using compass, solar and satellite navigation.

She is carting her own food and fuel on a sled she drags behind her, and carries a shotgun to ward off polar bears.

If she makes it she will be the first woman to have trekked solo to both Poles. She was the second woman to trek alone to the South Pole in 2004.

As of Easter Sunday, she had 324 miles to go. And warming or no warming, she is feeling the Arctic, with mild frostbite on two toes.

She is examining global warming effects for a polar research institute at Cambridge University. "I'll be monitoring the temperatures, wind direction and comparing the ice conditions to 10 years ago," Stancer said in a telephone interview from Resolute Bay, where it was minus 45 degrees Fahrenheit several days before she took off.

"If I can come back as an ordinary person with a firsthand account, that message will hit home and awaken individual consciences about cleaning up our own back yard," said Stancer.

Her biggest obstacle, she says, is time -- the period in which the ice is safe enough for a plane to land and pick her up shrinks every year as the ice cap melts. Pilots say she has only 60 days to arrive at the North Pole, though most teams typically take longer.

"You know, everyone is going ooh-la-la and being indignant about our climate change. But what did they expect?" Stancer says of those who are just waking up to global warming. "Why are people surprised that this is a living, breathing planet?"

Why leave her banker husband and young son back in Britain for isolation at the top of the world?

"There is very little between you and nature and God," she says. "All your layers of materialistic crud just drop away and your life and its priorities are distilled down to pure survival."