This paper was written as part of the 2010 Alaska Oceans Sciences Bowl high school competition. The conclusions in this report are solely those of the student authors.
Shrinking Ice and its Perceived Effects on the Subsistence Sources of Mountain Village, Alaska
The latest Arctic sea ice data from NASA and the National Snow and Ice Data Center in Boulder, Colorado, show that the decade-long trend of shrinking sea ice cover is continuing. New evidence from satellite observations also shows that the ice cap is thinning as well.
Arctic sea ice works like an air conditioner for the global climate system. Ice naturally cools air and water masses, plays a key role in ocean circulation, and reflects solar radiation back into space. In recent years, Arctic sea ice has been declining at a surprising rate.
Scientists who track Arctic sea ice cover from space announced that this winter had the fifth lowest maximum ice extent on record. The six lowest maximum events since satellite monitoring began in 1979 have all occurred in the past six years (2004-2009).
Until recently, the majority of Arctic sea ice survived at least one summer and often several. But things have changed dramatically, according to a team of University of Colorado, Boulder, scientists led by Charles Fowler. Thin seasonal ice—ice that melts and re-freezes every year—makes up about 70 percent of the Arctic sea ice in wintertime, up from 40 to 50 percent in the 1980s and 1990s. Thicker ice, which survives two or more years, now comprises just 10 percent of wintertime ice cover, down from 30 to 40 percent.
According to researchers from the National Snow and Ice Data Center the maximum sea ice extent for 2008-2009, reached on February 28, was 5.85 million square miles. That is 278,000 square miles less than the average extent for 1979 to 2000.
What is happening in Alaska?
Water bodies throughout almost all of Alaska are shrinking. In an exhaustive study of closed ponds, scientists have documented a significant loss in the number of ponds in key ecological areas in the last half of the 20th century, including: Copper River Basin (54% loss in number of ponds); MintoFlats (36% loss); Innoko Flats (30% loss). (See Figure 1.)
Trees throughout Alaska have been adversely affected by global warming, including white and black spruce, yellow cedar, birch, and larch.
According to a study that analyzed thousands of satellite images taken over two decades, there are vast reaches of boreal forest where photosynthesis has decreased over the last 22 years. In central Alaska, where it is dry, white spruce and black spruce have shown documented declines in growth. Projecting forward, a 4°C increase in July temperatures would result in no growth of these species in much of interior Alaska. (See Figure 2, 3, and 4.)
The Arctic Ice Cap is a key ecological component of Alaska's Beaufort and Chukchi Seas. There was a record low amount of Arctic sea ice in September 2005, and it failed to recover. Between 1979 and 2005, an area twice the size of Texas has melted away, over a 20% decrease in the minimum summer area. In November 2006, ice coverage was the lowest ever recorded for that month. The Bering Sea Ice Sheet is also retreating with documented biological impacts. (See Figure 5.)
Polar bears (figure 6) rely on sea ice for their survival, including feeding, mating, and resting. Because of global warming, Alaskan polar bears have experienced less sea ice for their habitat, drownings, dislocation from sea ice, cannibalism, starvation, smaller skull size, and higher cub mortality. Similar ice conditions and trends in the Western Hudson Bay population in Canada have resulted in a 22% population decline in 17 years.
Southern Beaufort Sea polar bears have been estimated to be as high as 2,500 bears, and then 1,800 bears. Recently, using the most rigorous surveying methodology yet, the population is believed to be 1,526 bears.
The decrease in sea ice jeopardizes this species. Between 1979 and 1991, 87% of Alaska polar bears surveyed were found mostly on sea ice. This percentage fell to 33% from 1992 to 2004. The impacts include a statistically significant decline in the survival rate for first year polar bear cubs in the southern Beaufort Sea from 0.61 per adult female between 1967 and 1989 to 0.25 per adult female between 1990 and 2006. Skull measurements of both first year cubs and adult males were also statistically significantly smaller.
Because global warming in Alaska is resulting in accelerated shoreline erosion, melting permafrost and increased flooding, infrastructure is being damaged, and in some cases entire communities must be relocated. Some shorelines have retreated more than 1,500 feet over past few decades. In Western Alaska, the community of Newtok lost two to three miles of shore in 40 years. Approximately, 184 communities are at risk from flooding and erosion according to a General Accounting Office estimate.
In 2005, while the nation focused on hurricanes in the Gulf of Mexico, Western Alaska experienced a brutal storm, adversely affecting 34 communities. The storm surge in Nome was nine feet above normal high tides with waves of 12 to 15 feet. Newtok saw five to ten feet of beach disappear along with equipment like a 1,000-gallon fuel tank, and Unalakleet lost ten to twenty feet of beach. (See Figure 7.)
What Native People Across the Arctic are Observing
- More persistent clouds
- More warm weather
- Warmer winters
- More extreme weather
- Less snow
- Snow melting earlier
- Less sea ice in winter
- Thinner sea ice in winter
- Later ice freeze-up
- Earlier ice break-up
- Lower water levels in lakes and rivers
- Tree line moving north
- Willows and shrubs getting larger
In The Next Hundred Years We Can Expect
- Warmer winters abd wetter summers
- More extreme weather events
- Less sea ice
- More wildfires
- Melting permafrost
- Earlier break-ups and later freeze-ups
- Rising sea levels
What is Happening in Our Village?
- Population in July 2008: 826, population has increased 9.4% since 2000
- Estimated median household income in 2007: $41,166 (it was $31,250 in 2000), Alaska median household income in 2007: $64,333
- Culture: Yupik
- Language: English/Yupik
- Subsistence Activities: Fishing, hunting, and berry picking
The Yupik culture is rich in tradition and ritual. The Lower Yukon Delta is now home to 9,000 Yupik Eskimos. (See Figure 8.) Their rivers are rich with salmon that sustain the Yupi'ik populations in the area. This abundance supported the development and spread of the culture thousands of years ago, leading some to call this coastline the "cradle of Eskimo civilization."
What Some Elders and Fisherman of Mt. Village Say About the Effects of "Melting Ice"
Question 1: How much do you think the population of the fish decreased in the Yukon River over the last 50 years?
- "It got real low, not as much King Salmon as there used to be." -Paul Brown
- "It has decreased by 10%." -Jack Wilde
- "It has decrease by thousands over the years." -Harry Wilde
- "I don't think it really decreased that much maybe 20-25%." -Pete Peterson
- "King salmon-about 30-35% might even be bigger." -Elmer Beans
- "Long ago there used to be lots of fish and now they're getting really low, especially the summer fish; king salmon, chums, and silver. About more than half maybe." -Ida Lawrence
Question 2: Did you notice any climate changes? If so, what do you think are the causes?
- "Temperatures are a little milder and the snow is getting less. Probably because the global warming, people burning fossil fuels, and the carbon dioxide in the air." - Elmer Beans
- "River losing depths. Probably automobile use." -Paul Brown
- "Just balance of life on earth, the way us human beings treat the world by trying to live the way we want to live." -Jack Wilde
- "Only the changes of people do to the land and water." -Harry Wilde
- "A lot yeah, the weather is getting warm and permafrost disappearing. I don't know maybe pollution going up in the air." -Pete Peterson
- "Yes, that's changing too. There's too much smoke around the sun." -Ida Lawrence
Question 3: What can you say about the melting ice?
- "Not good because the arctic animals are starting to become extinct." -Paul Brown
- "I wish I lived there, I'd tell you." -Pete Peterson
- "It's not surprising because I heard it from an old man reading the bible prophesies who talked about cold places getting warm." -Ida Lawrence
- "Has something to do with global warming. Sensitive up north. Hope it's just the weather cycle." - Elmer Beans
Question 4: Do you believe in global warming?
- "Yes!" -Paul Brown
- "Global warming isn't my concern." -Jack Wilde
- "Not really, but starting to because I can see it, was colder growing up." - Pete Peterson
- "I do because it goes with melting ice."-Ida Lawrence
- "Yeah." - Elmer Beans
- "No." - Harry Wilde
Question 5: Do you think global warming has to do with the effects in the subsistence activities and the Yukon River?
- "Yes, king salmon population is decreasing every year." -Paul Brown
- "Yes, but I don't understand it." -Jack Wilde
- "No, but still is making a big impact on how the fish are today, how they have been, and to the people." -Harry Wilde
- "It has effected just about everything." -Pete Peterson
- "They might be, yeah. It has to be." -Ida Lawrence
- "Yeah it affects the number of fish we get. Ptarmigans also. Trees grow where they never use to."
Question 6: What can be done?
- "People can start walking more often." -Paul Brown
- "Change our way of doing things. Maybe go to solar or wind energy instead of using so many diesels for energy." -Pete Peterson
- "I cannot answer. People from different countries are getting prepared for it." -Ida Lawrence
- "Developed countries can reduce the number of carbon dioxide being put in the air. Develop machines, for example, snow-machines, four-wheelers, cars, trucks, etc., that are energy efficient." -Elmer Beans
Question 7: How has the mammal population changed throughout the years?
- "It has changed by decreasing." -Paul Brown
- "It has its ups and downs. High population of moose, then it's stabilized. High population of lynx, then stabilized. It happens, and more is happening all around the world." -Jack Wilde
- "The moose are decreasing. It could be starvation, but it seems harder now days to find and catch moose as well as other large game." -Harry Wilde
- "I don't know much about mammals." -Pete Peterson
- "Some of the animals are getting fewer and fewer maybe because global warming." -Ida Lawrence
- "Most notable, moose became very abundant. Trap animals fluctuate naturally." -Elmer Beans
Suggested Courses of Action
Based on interview
- Walk more often
- Change our way of doing things, like using solar or wind energy instead of diesel
- Unplug electronics when not in use
- Turn down the heat at home
- More information campaigns
- Speak up and be heard
Web Site References
- http://www.washingtonpost.com/wpdyn/content/article/2008/08/26/AR200808 2603014.html