The end of winter: A search for vanishing snow and ice around the Northern Hemisphere

Updated 1018 GMT (1818 HKT) December 29, 2021

Porter Fox is the author of The Last Winter: The Scientists, Adventurers, Journeymen, and Mavericks Trying to Save the World, from which this story has been adapted.

Kulusuk, Greenland (CNN)Twelve Greenlandic huskies toil against a 40-mile-per-hour headwind, as box store-size icebergs and rugged 10,000-foot peaks slide past. They are as inspiring as they are terrifying — until my ski goggles ice-over, blinding me for hours.

I've been sitting on the back of a dogsled for three hours now, nestled between a bag of frozen seal blubber, a rifle and three duffel bags as we cruise over the second largest ice mass in the world. Two sleds behind us carry more passengers from Pirhuk Greenland Mountain Guides' annual dogsled expedition into the Arctic Circle. The trip began in the morning, on the outskirts of Kulusuk, a small island on Greenland's remote southeast coast. Discussion then revolved around what had been an unusually warm winter and whether or not the sea ice would be thick enough to sled over. Most of our journey would be on fjords and bays, and if the ice didn't freeze solid we would likely have to turn back.
Sitting on the back of the sled, it's hard to believe that anything in the world is not frozen solid. But I know better. Greenland is the last leg of a 10,000-mile tour I've taken of the Northern Hemisphere's snow line, documenting how climate change has melted snow and ice.
In most parts, winter isn't coming. It's going.
Unlike Antarctica, where melt rates depend on the stability of floating ice shelves, the issue in Greenland includes surface melt. Warmer air temperatures melt the ice from above, then meltwater percolates through the ice to the sliding bed, lubricating its base and quickening its descent into the ocean.
On the first leg of my world tour, snow scientists in Oregon told me that a million-square miles of spring snowpack in the Northern Hemisphere had disappeared — in just the last 50 years. Others, in Washington's North Cascades, explained how the length of winter was projected to decline across the US, in some locations by more than 50% by 2050 and by 80% by 2090. Spring snowpack depths across the country are forecast to drop during the same period by 25 to 100 percent, likely closing all but a handful of ski areas in the US. The lack of winter snowpack — and its spring melt runoff — will also become a primary driver of Western forest fires.
After a life of skiing and exploring sub-zero climes, the thought of brown summits in the Cascades, Sierras, Rockies and Alps for much of the winter was shocking to me. What surprised even scientists were statistics like the fact that, for the first time in history, nearly every glacier in world was receding — and now melting twice as fast as they were in 2000. The Alps lost half their glacial ice since the 1800s, and most of what remains will likely be gone by the end of the century. A recent report about the "Doomsday" Thwaites Glacier in Antarctica suggests that the ice shelf holding it back could shatter within five years — potentially raising sea level by two feet and flooding coastal cities like New York City, Mumbai, Tokyo and Shanghai. Further proof of how greenhouse gas emissions are indelibly altering our planet: so much ice has melted from the poles in just the last few decades that the rotational axis of the earth has changed.
Greenlanders run their dogs in a fan formation instead of the neat pairs Alaskan mushers use. The fan allows Greenland dogs to spread their weight out on thin sea ice.