Alaska is warming twice as fast as the rest of the U.S., and the Yukon-Kuskokwim Delta is seeing the impacts faster than than most of the state.
Rick Thoman tracks the average number of times temperatures fall below freezing in Bethel.
"Of course last year, December was very mild and we didn’t get much accumulation for the first three weeks in December [of last year]," Thoman said.
Thoman is a climate scientist based in Fairbanks who, with the help of Bethel Search and Rescue, monitors the daily temperatures to figure out the impacts to the Kuskokwim River.
Regional temperatures are a big deal because Y-K Delta residents can only travel to other villages by water or by plane. In the past the river usually froze thick enough before December to allow for an ice road, but that hasn’t been the case for the last couple of years. 2017 was the warmest December on record for Alaska, and this year is still not cold enough to for thick ice to build up on the river. Bethel has substantial weather data from the airport dating back to the 1920s.
"What we got from [Bethel Search and Rescue] were estimates of dates of when the river near Bethel became what we might call marginal for travel, or when it was safe," Thoman said.
Thoman takes that historical data and compares it with the numbers from BSAR to find out how many days are below freezing in Bethel. From there he can establish a pattern of warming temperatures. The consequences from those warmer temperatures are like a line of dominoes. On the frontlines are the coastal villages on the Bering Sea. The ocean temperatures are rising, sea ice is getting thinner, and that changes how these communities hunt and fish for their food for the winter. Alaska Native communities are especially vulnerable because they are deeply connected to their food sources and the environment.
"Most of our communities are very dependent and proud of their subsistence economies, and that requires that the environment be stable. Our communities are extremely resilient, but that comes at a cost," Thoman said.
Climate change can also affect cultural activities besides subsistence, like sled dog racing. Take the Kuskokwim 300, a scrappy, mid-distance sled dog race that takes place in Bethel every January. Last year, the Kuskokwim 300 Race Committee had to change the race course at the last minute because of warmer than usual temperatures. The committee puts on other local races, and has had to delay the first local race of this year.
There are indirect consequences as well.
"Human health or just anxiety over food availability, resource availability, or travel safety that is all combined to make the Y-K Delta particularly susceptible to the very rapid changes that are going on," Thoman said.
Thoman says that while temperatures might fluctuate year to year, the long-term trend toward warmer temperatures is already in motion. He also says that collecting the data about river conditions can help scientists predict when the Kuskokwim River will be safe to travel in future years. As for this winter, he says that based on the data he has now, the river could freeze over enough to travel on by Christmas.