Original article posted Jan. 31, 2011

FAIRBANKS - Climate change has already begun to make life difficult for state transportation managers. And they expect it to become a bigger and more expensive challenge if warming trends continue as predicted.

"With over 6,600 miles of coastline and 80 percent of the state underlaid by ice-rich permafrost, you can certainly imagine we are at the forefront of climate change impacts," said Mike Coffey, maintenance and operations chief for the Alaska Department of Transportation and Public Facilities.

Coffey discussed the impact of climate change on transportation in a webinar last week, hosted by the Alaska Center for Climate Assessment and Policy at the University of Alaska Fairbanks. New challenges include warming permafrost, coastal erosion and the potential for more dramatic storms and flooding, he said. These could lead to more highways and facilities cracking, icing up or even washing away. The hardest-hit areas are northern, western and Interior Alaska, where roads and structures are built over permafrost and near the coast.

Overall trends

Climate data show Alaska has warmed in the past century and is likely to continue warming. Some regions and seasons will experience more warming than others, according to UAF climate research. The research, by Scenarios Network for Alaska Planning, projects average monthly temperatures for different communities using international climate models and predicted greenhouse gas levels. In Fairbanks, for example, the average January temperature climbed approximately three degrees from the late 1990s to this past decade. It's projected to go up about two more degrees in the next two to three decades.

Climate change looks more dramatic in a place like Newtok, a Yupik village on the west coast of Alaska. Average January temperatures rose about six degrees from the 1960s to last decade. They are projected to climb another two to three degrees by 1940 and approximately five additional degrees by 2060.

The effects of warming

Melting permafrost is the biggest challenge for roads and infrastructure, Coffey said.

"Permafrost is essentially a function of average annual temperature. If average annual temperature goes above the freezing point, eventually you'll see changes," said Nancy Fresco, coordinator at Scenarios Network for Alaska Planning.

In most of the nation, roads deteriorate when pavement wears out. But in Alaska, permafrost often gets them first.

Melting permafrost causes pavement to sink and often crack.

"Gravity tends to move material down to fill the void, and we get a depression in the road," Coffey said.

Severe melting can make roads as wavy as ribbons, as seen on sections of Goldstream and Chena Hot Springs roads.

"This increases maintenance costs and impacts the DOT budget," Coffey said.

The state spends roughly $11 million per year dealing with permafrost-affected roads and has for about eight years, he said.

The more remote the infrastructure problems, the more expensive they are to fix. While gravel or crushed aggregate used for reconstruction might cost $20 per yard in Anchorage or Fairbanks, it can cost up to $400 per yard in Newtok or $1,000 per yard in Savoonga, Coffey said.