Frozen soil underlies much of Alaska. This "permafrost" consists of cavities of pure ice and ground ice, or ice that forms in pore spaces and bonds to sediments in the soil. While the deeper permafrost layer remains frozen, the upper layer responds dramatically to changes in temperature, thawing further downward as surface temperatures rise.

Across Arctic and sub-Arctic lands, lakes are a dominant feature of the landscape. Plant and animal life depend on them, as do Alaska Native fishermen and hunters. Scientists have noted that in places where the permafrost remains intact and impedes drainage, lake areas are in fact growing. However, the farther south one goes, permafrost is thawing to deeper levels. With the frozen layer gone, water percolates through the soil to aquifers below, draining the lakes.

This shift from aboveground to belowground storage of water is impacting wildlife and the broader ecosystem, and may also affect both weather and climate. A habitat without surface water can no longer sustain current populations of migratory birds, fish, and other wildlife. As water is removed from the surface, the danger of forest fires will increase. Because evaporation from lakes creates clouds and rain, scientists assert that the loss of lakes may also affect local weather. Lastly, melting permafrost may accelerate global warming by releasing methane into the atmosphere. Methane's capacity to warm the atmosphere is even greater than that of carbon dioxide, and it is believed that a lot of methane is trapped in the Arctic soil.

Melting permafrost along major river banks, such as the Yukon River and the tributaries that cover much of Alaska, will likely increase erosion, with effects on both animal and human populations. As sediments accumulate in these rivers, the rivers can become shallower, impeding salmon that migrate upstream to spawn. Many Alaska Native villages located along rivers are also threatened by erosion if permafrost can no longer hold river banks intact.

The effects of melting permafrost may be widespread and lasting, affecting the habitats, wildlife, and people who rely on the land and living things for their ways of life, food, clothing, and shelter. The cost of relocating entire communities is high, both in monetary and cultural terms. Damaged houses would have to be abandoned, forcing their owners to rebuild elsewhere or to move to regional hubs and urban centers if there were no options to relocate. Perhaps more significant, however, would be the severing of longstanding ties to land that has sustained the Alaska Native peoples for generations. Language, stories, spirituality, culture, and ways of life of Alaska Native peoples derive from having lived in one area for hundreds of generations.

Print Background Essay