"You can think you're buddies with a walrus one minute and the next minute it's trying to kill you," Arctic photographer Paul Nicklen said. "I would rather get in the water with a great white shark, than a walrus."
Then he went on to tell us how to do it -- or, at least, how he does it.
"I will sometimes spend 24, 48, 72 hours sitting on an ice pan with a group of walruses," he told ABC News. "I will get to know these walruses to the point they get so relaxed with me that I can rest my head against a walrus and fall asleep with them on the ice. Then one of them slips into the water, and it won't feel threatened by me. I can slip into the water with it and get a couple of shots."
Now 41, Nicklen has lived in the high Arctic since he was 4 when his parents moved to Baffin Island. His playmates were Inuit kids. He went on hunting parties with the elders whenever he could.
"The snow and ice were my sandbox," he said.
His images are a stunning and unique combination of abstract beauty and the raw wild, other-worldly, in need of nothing human. Beauty, science and a dangerously warming world have all become one in the life and work of Nicklen, a biologist-turned photographer.
"Where I grew up, we had no telephone, no radio, no television. We had no distractions."
Other than the limitless Arctic nature. Nicklen is now one of National Geographic's premier photographers.
He has obviously seen deeply into the threatened world.
His arresting photo of massive polar bear tracks in the snow seems to capture time itself -- it places the power of the bear in the fragility of the disappearing icy world it needs for survival.
Nicklen prefers photos to video. "A picture is always sitting there in front of you. And I think, you know, it just takes one image to get someone's attention."
Attention is what he's desperate to get for the beautiful world he's watched change radically from the global warming he believes is human-induced for the 37 years he's lived there so far.
"They're going to lose the entire extent of sea ice in the summertime in the Arctic in the next 7 to 15 years," he told us, echoing what our ABC News teams have been hearing from American scientists for the past couple of years.
"It's going to have such catastrophic effects before the temperatures actually level off. If we lose ice, we stand to lose an entire ecosystem."
His feeling for ice is organic.
"Ice is like soil in the garden, stuff just cannot survive without sea ice. You realize through my photography, I hope, how interconnected these species are to ice."
Nicklen got his university degree in biology, but soon came to feel he would give more to the world if he did biology with his camera.
Nicklen says he wants city people to see deeply into a world that greenhouse emissions are changing.
"I see all these species as friends -- not as a species that is below me, but as brethren."
When he takes his camera underwater in the frigid Arctic seas, his pictures only gain in magic.
The cover of his new book of photos, "Polar Obsession," shows a white bear accompanied by his own reflection swimming upside down above him -- somehow reflected on the underside of the ocean's glassy surface.
A big-brained beluga whale dives down smiling...as sleek as a white torpedo.