Not much time left for Alpine ice
Austrian climate scientists aren’t mincing words when it comes to the continued alpine meltdown caused by global warming.
“It was a bad year for Austria’s glaciers,” scientists with the ZAMG said last week, announcing that the Pasterze Glacier, below the country’s highest peak, thinned by 2 meters in just one year. At the current melt rate, the Pasterze glacier’s tongue is likely to disappear altogether in another 40 years.
“The ice-mass loss was particularly high this year,” said glacier expert Berhard Hynek. The winter snow cover melted early and the ice was exposed to sun and warm temperatures for a very long time,” he said, adding that other glaciers monitored by the agency also thinned by an average of about 2 meters – equal to the losses measured during the record melt years of 2003 and 2012.
Best scientific estimates, including by the IPCC, project that about 80 percent of the glaciers in the Alps will be gone by 2100.
The ZAMG looked most closely at glaciers in the Hohe Tauern range, especially the iconic Pasterze below the Grossglockner, where they documented downright disintegration of the ice. At the lower end of the glacier, summer temperatures are now so warm that the glacier is thinning by about 10 meters each year, regardless of whether it’s a “warm” or “cold” summer, Hynek said.
The researchers also documented another climate-warming feedback. They said meltwater that runs over the surface of sun-warmed rocks and cliffs works its way beneath the surface of the glaciers, melting the ice from below.
“Several parts of the Pasterze that collapsed this summer showed that effect. Combined with the surface melting, this causes thinning of up to 20 meters per year in some localized areas,” Hynek said.
The ZAMG is working with other institutions and companies to make their measurements even more precise, including ice-scanning lasers that can make readings down to a centimeter scale. The instruments show the Pasterze is thinning at the rate of about 5 meters per year. Since 2012, the rubble-free tongue of the glacier has retreated by about 600 meters. On average, the ice tongue is about 100 meters thick, so the math is pretty clear.
Low winter snowfall in parts of the Alps didn’t help. The ZAMG weather station on the Pasterze measured 1 meter of winter snowfall, which was completed melted off by late May. The melt period lasted through mid-September; as a result, the glacier thinned by 7.2 meters at the weather station.