Warmer winters, thinner ice, stranger weather -- climate change has begun to undermine subsistence life along the Yukon River, according to a new federal study that collected and analyzed observations by Native residents in two southwestern Alaska villages.

"They expressed concerns ranging from safety, such as unpredictable weather patterns and dangerous ice conditions, to changes in plants and animals as well as decreased availability of firewood," say the researchers in this story about their work that was posted by the U.S. Geological Survey.

The study, published this month in the journal of Human Organization, found that hunters and elders in the Yup'ik communities of St. Mary's and Pitka's Point noticed a litany of dramatic climate shifts over the course of their lives, forcing changes in how they gather food and wood while making it more difficult to read the sky correctly before heading out into the tundra.

Among the findings:

• The weather seems to change more quickly than it used to -- sometimes growing unexpectedly worse -- making it harder to plan trips into the country to hunt or gather food.
• Spring snow depth has decreased, leading to failures in the summer crop of salmonberries -- an important food staple -- once the tundra dries out.
• Spring flooding doesn't last as long, and the quicker plunge in river levels following breakup has an unexpected consequence. The year's new supply of driftwood logs -- traditionally used to replenish firewood caches for heating homes -- now sometimes gets stranded away from the riverbank in brush, where it's harder to find, haul out and cut up.
• Rivers themselves don't freeze as hard or as long during winter, and contain larger and more frequent spans of open water, making travel by snowmachines and dog team dangerous. During summer, more extensive gravel bars make boating more difficult.
• Lots more moose; fewer ptarmigan.

"From what I remember, you'd be lucky if you went out hunting and you'd see maybe eight (moose)," one long-time hunter told the scientists. "Today you can see eight in a bunch."

Seeking indigenous knowledge of climate change

The fieldwork took place in the spring of 2009, when the scientists conducted in-depth interviews with 10 men and three women from the two villages, located a few miles apart near the confluence of the Andreafsky and Yukon rivers, almost 450 miles due west of Anchorage.  Part of the goal was to focus on an inland subsistence community -- most previous studies of Native perceptions of climate change have scrutinized coastal villages.

The scientists also compared the observations to records of temperatures and precipitation, as well as studies of changes in vegetation and game, and found the Native observations tracked and illuminated those made by western scientists.

"Many climate change studies are conducted on a large scale, and there is a great deal of uncertainty regarding how climate change will impact specific regions," explained USGS social scientist Nicole Herman-Mercer, who conducted the project with two co-authors, in this story. "This study helps address that uncertainty and really understand climate change as a socioeconomic issue by talking directly to those with traditional and personal environmental knowledge." 

Almost all of the people interviewed noted that the weather has become much warmer and more unpredictable than when they were young.

"Those old people noticed it first," one respondent said. "They're not around anymore, they're all underground. They used to tell me, 'What's going on with this weather?' They noticed, sometimes it's too hot, sometimes it's too cold."