Global warming threatening the future of iconic dog sled races around the world

Climate change could continue to complicate iconic dogsledding races around the country as rising global temperatures make snowpack in traditionally cold climates less reliable.

Some of the northernmost U.S. states like Alaska, Idaho and Minnesota have faced challenges in hosting dogsled races in recent years as warmer winters made the terrain unsustainable to pull sleds for long distances.

The Iditarod Trail Sled Dog Race, the 1,000-mile trek across the Alaskan wilderness known as the "Last Great Race on Earth," kicks off its 53rd annual competition on Saturday -- but the start of the race was moved from Anchorage to Fairbanks, about 360 miles to the north, due to a lack of snow along a dangerous stretch of the trail on the north side of the mountains where there is basically no snow at all.

"It's just a frozen ground and bare, dry tundra grass," Rick Thoman, a climate specialist with the International Arctic Research Center at the University of Alaska Fairbanks, told ABC News.

Last year, the John Beargrease sled dog marathon in Minnesota was postponed and ultimately canceled due to low levels of snow. The 400-mile race is scheduled to start on Sunday after it was delayed by more than a month due to warm temperatures and a dangerous trail.

The Idaho Sled Dog Challenge faced difficulties in 2024 as well due to the absence of winter weather, but the race ultimately took place in late January 2024. The routes for the 300-mile and 100-mile races were determined to be safe after snowpack measured between 6 and 8 inches.

A warming climate is making race routes less reliable

The disappointment extends to the dogs when races are canceled, Jennifer Freking, a musher for Beargrease, told ABC News. Last year, some 1-year-old dogs were robbed of their first race to show off their hard work during training season, Freking said.

"They love going to the race," Freking said. "The dogs get really excited. The dogs get really keen on the adventure ahead."

Winter temperatures in places like Minnesota and Alaska are variable year over year but showing an upward trend, according to climate scientists.

There has been a "very obvious increase in temperatures" in Minnesota between 1895 and 2024 -- especially in the northern region of the state, Nate Meyer, associate director of the University of Minnesota Climate Adaptation Partnership, told ABC News.

Average temperatures in Minnesota have increased by about 4 degrees Fahrenheit, but low temperatures in the winter have increased the most -- by about 8 degrees Fahrenheit, Meyer said.

"We've observed a change in our winter low temperatures, or overall cold winters, in the past century or so," Meyer said. "We project that that will continue in the future."

In Alaska, annual average temperature has increased by 3.4 degrees Fahrenheit over the past 50 years. Annual race conditions for Iditarod can be as variable as the winter seasons, Thoman said.

In 2019, there was a lack of sea ice on the Norton Sound portion of the Iditarod trail, but route conditions were actually decent in several of the years that followed, Thoman said.

This year, however, is proving to be different -- with a notable lack of snow in several portions of the Iditarod route, Thoman said.

The precarious nature of future races is an "undeniable reality," Freking said.

"We see these extreme temperature jumps in 48 hours," she said.

Race organizers must adjust to keep traditions alive

Since its inception in 1973, Iditarod has earned the reputation of a grueling battle among teams consisting of fierce competitors. Historically, the teams of dogs and mushers run from Anchorage to Nome to commemorate the route traveled by 20 dogsled teams in 1925 to deliver medicine amid a diphtheria epidemic.

It takes about 10 days for the first mushers to complete the route.

For the first 30 years of the Iditarod's history, the race never had to be moved.

"Now this is four times in the last 23 years," Thoman said. "So that, in itself, probably tells us something about the changing environment."

At least 6 inches of snowpack on the ground is necessary to keep dogsled teams safe as a general rule, Thoman said.

Snowmaking equipment may be increasingly utilized in the future, as will stockpiling snow to truck out to the path to ensure enough to pad the routes of the race, experts say.

A warming climate may pose challenges for race organizers, but in Alaska, it is possible for long-distance races to continue with proper adaptations to the course, Thoman said.

Shorter races that are tied to one geographic area may be more in jeopardy, Thoman added.

"Those will likely become more difficult to do in coming decades, because they just don't have the space for course adjustments," he said.

On Thursday, the Beargrease was still being altered because there was no snow in Duluth, Freking said.

Dogsled organizers and participants will need to continue to be flexible, but there is still a future for racing, Freking said.

"Weather extremes keep us at awe but it’s not the end of racing," Freking said.

ABC News' Emilie Richardson and Leah Sarnoff contributed to this report.