Sprawled on a massive sheet of ice that was shifting beneath him, James Balog looked down into a 2,000-foot-deep crevasse and aimed his lens.

"I'd obsessed for four years about getting that shot," he recalled. "I figured I'd have about two minutes. There was a crack in the ice where my waist was, and a tremendous amount of uncertainty. Where the ropes were anchored, I couldn't count on them to hold me. But once you've taken that initial investment of risk, you say, 'OK, it hasn't broken yet,' and go to work."

That experience in Greenland was one of many dangerous moments for Balog, a renowned environmental photographer who embarked six years ago on what he dubbed the Extreme Ice Survey. He and a team of explorers and scientists set up cameras in some of the most frigid, rough and remote corners of the world to record the rapid rate at which glaciers are now melting -- losing hundreds of feet a year in some cases. So much for the notion of moving at a glacial pace.

Balog will be in town Friday for the opening of "Chasing Ice," a film about his project, along with Minnesota-based polar explorer Will Steger. While the documentary is partly a profile of Balog and the passions that drive him, it also rings a breathtaking alarm bell about climate change. The film, from the producers of the Academy Award-winning "The Cove" (about dolphin slaughter), is on a short list of 15 documentaries in this year's Oscar race.

Glacier melt seems a problem far removed from our daily lives. Geographically, at least, it is. Humans don't generally live near them, and relatively few have seen one up close and personal. But videos that Balog's crew compiled from 25 time-lapse cameras, which snapped images every half-hour of daylight at several locations around the world, show the mighty monsters disappearing before viewers' eyes.

"Cameras reveal reality in a way mere numbers don't," said Balog, who also has a science background and was once a climate-change skeptic himself.

Based in Boulder, Colo., Balog, 60, had already gained accolades for his magazine work and photo books featuring portraits of trees and endangered species. EIS was originally funded by National Geographic and other sources, but now relies on private donations.

In the beginning, he focused on just shooting the glaciers. But the scale of the melting he witnessed convinced him to broaden his ambition.

"We saw a chance to mix art and science, to tell a necessary story," he said.

First came the challenge of building sturdy stationary cameras the team could affix to sketchy surfaces, then ensure those cameras would work in subzero, 100-mile-per-hour wind conditions. Then they had to make their bodies work there, too, becoming mountaineer athletes as well as researchers, and encountering many life-threatening situations, including rockfalls and unpredictable ice cracking.

"Sometimes I look at these scenes and wonder what I was thinking," he said. "But you get possessed by the commitment, and it turns into an obsession."

Steger, who has traveled some of the same tundra as Balog, says navigating that kind of terrain is "harsh, but you adapt to it, and once you live in it, it's inspiring. Not just the vastness, but what you learn about yourself. And now it's changing."

In the early 1990s, Steger saw Antarctica's Larsen B ice shelf, then a 1,250-square-mile fringe along the Weddell Sea. In 2002, it collapsed in less than a month, due to several factors including global warming. "It just disintegrated," Steger said. "When you think something is permanent and it's not there anymore, it's a frightening, almost biblical feeling.

"Jim's work captures that better than anything else I've seen."

Frozen in time, on paper

For Balog, the Extreme Ice Survey has another, more personal facet: celebrating the art and architecture of ice in photographs -- literal freeze frames of structures that will never look that way again.

Balog has collected his most arresting stills in a book called "Ice: Portraits of Vanishing Glaciers." The pictures range from panoramic -- graceful stripes of eroded soil in ice; serpentine patterns created by meltwater above a thundering waterfall -- to close-ups of ice fragments so finely sculpted by nature they could be Swarovski vases. Who knew climate change could look so gorgeous?

"These pictures came out of falling in love with those sites, treacherous as they were," he said. "I wanted to capture the majesty and mystery of what I saw. I'd find myself going along without anything grabbing my eye and all of a sudden I'd see something that would stop me."

One example: Shards, the last vestiges of once-gargantuan glaciers, that he calls "ice diamonds."

For two years, Balog walked up and down the same beach in Iceland, shooting these fragments washed up by high tide. They were just curiosities to him until one day in 2007.

"I realized they were actually unique jewels. They came from 1,000-year-old ice formed high on the flanks of a volcano, the last surviving bits, each one worked by water, weather and time. They only exist for the couple of hours they sit on the beach. Then they become part of the rising global sea level. It was a profound moment for me."

Another highlight was discovering bubbles of ancient air trapped in an ice sheet, one summer night lit by the midnight sun on Greenland.

"It always freezes there at night, even if it's warm in the day," he said. "You hear the water moving around you, but in the midnight period, it stops. The wind, too. The light gets golden, pastel. It's so still it seems like the world is holding its breath.

"All of a sudden, at 1 in the morning, I saw a little melt puddle releasing air bubbles that had been trapped under a super-thin film of clear ice. They were probably 10,000 years old. That's the magic of the Arctic."

Not a matter of belief

Sometimes on an airplane, when Balog is reading a scientific article dealing with climate change, the guy next to him will ask if he believes in it.

"My answer is no, I don't," he said. "It's not an ideology or doctrine. Climate change is based on evidence. Lots and lots of it. We have to separate it from being a matter of belief, because that's why our society has a hard time dealing with it."

He said he understands why global warming went virtually undiscussed during the recent presidential race.

"I understand the pressures those guys are under, and am sympathetic in a way, but this is a real and present danger that will degrade our kids' futures," he said. "They're going to have to come up with a new name for Glacier National Park. Because those glaciers, they're going to be gone."

Kristin Tillotson • 612-673-7046