Climate change may still be debatable in some circles, but in Greenland—the world's largest island, covered by an ice sheet averaging 1.6 miles deep—it's an observable fact. And there is no more dramatic way to witness what may determine the earth's future (and to have a rip-roaring adventure besides) than on a dogsled. Bob Payne hangs on for dear life

In Ilulissat, a town on the west coast of Greenland, about 150 miles north of the Arctic Circle, it is late March, near the end of winter, when the days are growing long again but the sea ice is still solid enough, I have been assured, to support the weight of a dogsled.

On just such a sled, my guide, Johannes Mathaeussen, and I are about to set out on a four-day adventure across a white, treeless landscape. The sled, little more than a narrow wooden platform on runners, is piled about three stories high with all manner of gear and supplies, including a shotgun whose barrel I keep catching a boot on when for practice I climb atop the pile, where I am to ride, Mathaeussen tells me, "like a cowboy."

Our twenty-dog team, knowing that they are about to be given the word to do what they are bred for, which is to run, are yapping excitedly and straining against the metal ice screw to which their traces are still attached. But Mathaeussen—whose Danish-sounding name is a result of Greenland's longtime status as a dependency of Denmark, and whose flattened Inuit features are from a bloodline that originated, untold generations ago, somewhere on the high, cold steppes of Mongolia—is for the moment ignoring them.

Staring thoughtfully at the sky in the direction of the coastal hills that we will soon be ascending on our way to the frozen fjord on the other side, he finally says to me, "Snow is maybe coming." "How do you know?" I ask, following his gaze but seeing no clouds or any of the other signs that I assume his lifetime of surviving in this desolate land have taught him to read.

"I looked on the Internet."

His answer gives me pause, but I know it shouldn't. For thousands of years, Greenlanders, almost all of whom can claim to be some mix of Inuit, have been forced by nature to live such a tenuous existence that they still often append statements of intent or desire with the word immaqa (maybe). And in all those years, the one thing that has allowed them to survive is their ability to adapt.

"If the snow comes, what do we do?" I ask, having researched this adventure well enough to have some fairly vivid images of myself in an Eskimo Pie–like state of permanence.

Flashing me a grin that reveals a missing tooth or two, the forty-six-year-old Mathaeussen—who for most of his life has been a professional hunter and ice fisherman but who, like many of his contemporaries, has in recent years supplemented his income by taking tourists on dogsled adventures—pulls up the hood of his parka and pretends to be shivering.

The parka highlights, I can't help but observe on this fifteen-degrees-Fahrenheit morning, the contrast in our sartorial styles. I am standing here in the clothing the local adventure company that brought us together insisted I rent from them: sealskin pants and parka that are certainly warm enough, especially under the arms, but that make me look and smell like a stuffed animal. Mathaeussen, on the other hand, is wearing layers of moisture-wicking, water-repelling, color-coordinated gear from the likes of Patagonia and the North Face, gear that wouldn't make him look out of place if he were trying to survive in, say, a Starbucks.