This summer’s record-breaking temperatures hasten glacier, permafrost melt...
In late June, the Mendenhall Glacier was melting fast – and the lake below was rising. Reports of the water level were coming in every hour to the office of John Neary, director of the Mendenhall Glacier Visitor Center. He watched nervously as the readings showed a sharp increase, indicating that the lake was about to overflow its banks, sending rising waters into the visitor center.
Outside, visitors were scattered along trails, catching glimpses of the popular glacier in Tongass National Forest in southeast Alaska. Water had already begun creeping closer to the Nugget Trail, normally more than eight feet above the lake. Neary made the call: Close that trail and the nearby campground, and evacuate about 100 people. Warning signs were placed along other nearby trails, and glacier tours and trips to nearby ice caves were cancelled.
And then, on July 1, the thing he’d feared most happened. Glacial meltwater gathering in Suicide Basin, above Mendenhall Lake, finally punctured a dam formed by glacial ice. As more water rushed through the widening gap, the lake flooded, inundating nearby trails.
It wasn’t the first time that such flooding had occurred. The first overflow was in 2011, and since then, as the Mendenhall Glacier melts away, they’ve become more frequent – and more destructive. In 2014, the water rose to 11 feet, two feet over flood level, breaking a record set three years earlier. This year’s outburst set a new benchmark with the water rising to nearly 12 feet.
A few days before the Mendenhall glacial outburst, about 80 miles to the west, a large landslide on the Lamplugh Glacier in Glacier Bay National Park, which has been steadily thinning, caused tremors equivalent to those of a small earthquake.
As the climate warms, glacier retreat is just one impact that climate scientists expect to happen more frequently. Melting permafrost and sea ice are also causing major problems. Some Alaskan coastal communities have already been forced to move inland as sea level rise erodes the coastline and thawing permafrost causes infrastructure to fail.
Melting this summer is far-outpacing climate projections, says Julienne Stroeve, a research scientist for the National Snow and Ice Data Center (NSIDC), based in Boulder, Colorado.
Alaskan glaciers in total lose ice at a rate of around 75 billion metric tons each year, according to a 2015 study by the U.S. Geological Survey and University of Alaska, Fairbanks. But this summer, reports NSIDC, glaciers are melting 70 percent faster than the typical rate, thanks to warming temperatures.
Over the past 60 years, the state’s average temperature has increased by about 3 degrees, about twice the rate of warming experienced by the rest of the country, according to the Environmental Protection Agency, and over the past three months temperatures have run as much as 8 degrees Fahrenheit above normal. Under current climate projections, temperatures can be expected to rise up to 12 degrees in the north, 10 degrees in the interior, and 8 degrees in the rest of the state by 2050.
Of course glaciers aren’t the only mass melting in Alaska. In June, Arctic sea ice hit a new record low. The average sea ice extent in June, according to NSIDC data, was 100,000 square miles smaller than in 2010, when the last record low was set. NASA Landsat satellites found that over the past century permafrost in Alaska has warmed up to 7 degrees, and researchers from the University of Alaska, Fairbanks, say it could lose more than 60 percent of its current permafrost mass.
The various types of melting — be it from glaciers, sea ice or permafrost — have disparate effects on climate and sea-level rise, but all contribute to the instability of communities in the state. Glacier melt, globally, has added about a half inch of sea level rise per year or about 30 percent of total rise observed since 2003. As sea ice melts, it accelerates warming of Arctic waters because there’s less ice to reflects the heat from the sun, Stroeve says. Permafrost’s greatest impacts are to climate (methane gas is released as it melts) and to infrastructure built upon frozen ground that bends and breaks as the soil thaws.
While melting glaciers and lake outbursts, like the recent flooding at Mendenhall Lake, are more dramatic, it’s the sum of total impacts that will affect Alaskan populations. As melting from land ice, which includes glaciers, ice sheets and ice caps, as well as sea ice and permafrost continue, many communities are at risk of displacement. In Anchorage, Robin Bronen, executive director of the Alaska Immigration Justice Project, tracks climate events like glaciers melting as she develops programs that might one day provide aid to Alaskan climate refugees. Many villages in northwest Alaska already have crumbling infrastructure that’s fracturing as permafrost melts, and are consequently without running water. “This is an example of how completely unprepared we are to adapt to the radical changes that are happening to our environment,” she says. “The relocation of populations is going to be one of the most complicated strategies that humanity will have to develop.”
Currently, two northwestern Alaska villages, Shishmaref and Kivalina are considering relocation. Newtok has already started. In 2011, residents began moving to Mertarvik, about 9 miles away, but it will take until 2021 to finish the relocation, and by next year, erosion is projected to reach the school, the largest building in the community.
Bronen says that relocating residents from such communities should happen years before natural disasters force relocations, but presently there isn’t funding or any programs in place. “It fills me with despair,” she says. “If the United States doesn’t have the capacity to do this, what’s the hope that any other country will?”
July 18, 2016
Paige Blankenbuehler is an editorial fellow at High Country News. She tweets @paigeblank
original story HERE
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