Inland, another kind of ice is disappearing. Permafrost — rock and soil that remains below freezing for two or more years at a time — covers much of the state, creating a unique and sometimes challenging surface for construction and ecosystems.
In lower Alaska, patches of permafrost that had once created islands of trees within wetlands are melting, causing the trees to drown and die. Michael Ferrick, a research hydrologist with the military's Cold Regions Research and Engineering Lab, based in Hanover, N.H., has been observing this change in military-owned territory near Fairbanks.
"As the climate melts, the land subsides back into wetlands," he said. "Then you have a big ecological change."
Melting permafrost also carries consequences for developed areas. Two northwestern Alaskan native villages, Shismaref and Kivalina, must relocate because permafrost melt has led to extreme erosion, making the towns more vulnerable to storms.
One of the largest, privately funded construction projects of all time — the Trans-Alaska Pipeline — is also affected by melting.
The pipeline, which runs for 800 miles from the North Slope to the ice-free Alaska port of Valdez, is buried underground in parts and, in others, rests on platforms. Since 75 percent of the line traverses permafrost, any melting requires attention and occasional repair work by the pipeline's maintenance company.
"That increases the price of your gasoline," argues Weller.
Corell argues that a warming Alaska will need to be part of the consideration of new, proposed drilling in the Arctic Wildlife Refuge in northern Alaska. More importantly, he says, it should be closely watched as a model for dealing with global climate change.
"We have to define areas where we can get smarter about warming," he said. "Watching the Arctic may help us avoid substantial changes elsewhere."