A Trove of Old Photos Could Reveal the Future of These Arctic Glaciers
The Svalbard Islands, part of Norway, are warming seven times faster than the global average. Aerial pictures from the 1930s are helping researchers understand what that means for the region’s ice.
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By Raymond Zhong
The mammoth, ethereally beautiful glaciers of the Norwegian archipelago of Svalbard, near the North Pole, bear the scars of climate change more than almost anywhere else on the planet.
Over the past three decades, Svalbard has warmed twice as quickly as the rest of the Arctic region and seven times the global average. That is causing the islands’ glaciers to melt at an alarming rate, threatening polar bears and other wildlife, and adding to rising sea levels around the globe.
For a long time, though, predicting how quickly future warming might cause the ice to retreat took guesswork. In Svalbard and other places, most field measurements started only in the mid-20th century, and satellite observations even later.
Now, advances in computing are helping scientists bring old ice back to life in astonishing detail. Using black-and-white photos taken during mapping expeditions nearly a century ago, they are creating three-dimensional digital models of how the glaciers looked before modern record-keeping, and illuminating the ways they have changed over a longer stretch of time.
One of the largest such reconstructions to date, published Wednesday in the journal Nature, points to an unsettling conclusion: Svalbard’s glaciers could thin twice as fast in this century as they did in the last.
“Right now our predictions of future glacier change are not very grounded in all of the data that we already have from what’s happened in the last century,” said Emily C. Geyman, a graduate student at the California Institute of Technology and lead author of the new study. A deeper historical record lets scientists test how well their models of glacier changes line up with the past, Ms. Geyman said, before using them to peer into the future.
“This is a unique opportunity to look a bit further back in time,” said Ward J.J. van Pelt, an associate professor at Uppsala University in Sweden who contributed to the new research.
The team’s reconstruction of the Svalbard glaciers in 1936 reveals, in striking detail, how much some of the ice caps shrank between then and 2010. The average rate of loss was about 1.1 feet a year.
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