RAPID GREENLAND ICE MELT THREATENS 25 FEET OF SEA LEVEL RISE

RAPID GREENLAND ICE MELT THREATENS 25 FEET OF SEA LEVEL RISE

By Adam Cohen, Jan. 30, 2017

It’s as if there’s a new apocalyptic blockbuster in theaters, and Joerg Schaefer has a front-row seat.

Some of the world’s foremost climate scientists shared their latest field research reports at the annual Comer Climate Conference this past fall in southwestern Wisconsin. None was as jarring as Schaefer’s talk on his work in Greenland and the Himalayas. His data indicating the vastly increased potential for sea level rise and severe water shortages are harrowing.

The renowned Columbia University professor gave two presentations, each on a paper that he published late in 2016. The first described a groundbreaking mission to drill through 2 miles of ice in the center of Greenland. The cosmic ray burn that Schaefer and his team found on the bedrock beneath the glacier indicates that, contrary to conventional wisdom, Greenland was completely ice-free during certain interglacial periods over the past 2.6 million years. The isotopes that were present in the sample – traces of beryllium-10, aluminium-26, and chlorine-36, among others – deliver the telltale clues that appear when cosmic radiation bombards rock uncovered by ice.

Schaefer’s mood was heavy as we sat down to speak in the library of the Comer Family Foundation estate after he had presented his findings. Outside the window to his right, a concrete landing strip gave way to the rolling hills of the Midwest’s Driftless Area. On a shelf to his left sat a leather-bound copy of Darwin’s Origin of Species. But Schaefer seemed weighed down by the subject matter of the day, unable to appreciate the treasures around him. “What I showed you today is another piece of bad news,” he said.

The expedition’s results may mean that Greenland is much more susceptible to climate change than we had thought. As we continue to warm our planet, the Arctic island could deglaciate in a matter of decades. And if it does, it will mean almost 25 feet of sea level rise.

Joerg Schaefer at the Comer Climate Conference last fall. (Adam Cohen/MEDILL)

The second talk Schaefer gave was based on a foray not into the Arctic, but into the archives of the American intelligence community. In a paper he co-authored and published in September 2016, Schaefer compared modern NASA imaging with recently declassified spy satellite data dating back to the early 1970s in order to build a series of digital elevation maps that quantify glacial retreat in the Himalayas.

The study is unprecedented in scope, as it traces the movement of roughly 18,000 individual glaciers over three decades, from 1974 to 2006, and thus isn’t skewed by regional variation for factors such as elevation and precipitation. Additionally, the Cold War-era, school bus-sized satellites, launched into orbit by the U.S. National Reconnaissance Office to keep tabs on the Soviet army, provide a clear picture of objects as small as 2-feet wide. That’s a resolution higher than current Google Earth imagery.

Unlike the Greenland results, the significance of the Himalayan satellite data is unequivocal. The glaciers of the Asian mountain range, which hold the largest quantity of ice outside of the polar regions, are shrinking by 1 percent each year, and that rate is accelerating. Even with a conservative estimate of 1.5 degrees Celsius (roughly 2.5 degrees Farenheit) of warming above preindustrial levels by the end of this century, more than one-third of Himalayan ice mass would be lost.

“But it will be much more, because the warming will be more,” said Schaefer, who has done field research in the Himalayas. “And if you warm the global temperature by 2 degrees, you’re warming more than that in the higher mountains of Asia, because the high altitudes warm more.”

The global community will have to deal with at least a foot of sea level rise as a result of this Himalayan thaw. But more than 1 billion South Asians who rely on glacial melt for agriculture, energy production, and potable water face far more dire consequences.

“Right away,” said Schaefer, “if you are there for the first time, it becomes clear that glaciers are not just some abstract tourist attraction, which they basically are in Switzerland, where I did my Ph.D. There, if you change the glaciers, it’s kind of inconvenient for some skiers. In the Himalayas, it’s a very dominant part of the environment, and as soon as the glacier changes, the entire habitat of the people living in downstream valleys changes.” The water supply is paramount. “At some point, you will be sitting with no water at all outside of the rainy season in the big Indian rivers like the Indus and the Ganges and the Brahmaputra. This will be an epic disaster if it happens.”

Richard Alley, the Penn State geosciences professor who has authored numerous assessment reports for the Intergovernmental Panel on Climate Change, said that, even without taking diminishing water reservoirs into consideration, future heat stress will be enough to make life grim for the people of South Asia and the world’s other tropical regions.

“It is very clear that poor people in hot places get screwed by climate change,” said Alley. “When it gets unexpectedly hot, people die. And that’s not really close yet in Anchorage. But it may be closer in Ankara. And it may be way closer in some of the big cities of India. And it’s miserable long before it’s fatal.”

Toward the end of our interview, Schaefer shifted to a more optimistic call for action. He highlighted the work of Columbia’s Earth Institute, one of many American academic centers making strides in communicating the urgency of the situation by promoting collaboration between earth scientists, economists, political scientists, and other researchers. It is not too late, Schaefer insists, to take concrete action to save humanity from the most catastrophic climate outcomes.

“We are at a point where the message is so clear that we really can transfer something robust to policy makers,” said Schaefer. “We have to do the best we can. Predict and transform – bring this message to the decision makers, and prepare them for what might come.”

Photo at top: Aerial view of Himilayan glaciers in Bhutan. (Included in Joerg Schaefer’s presentation at the Comer Abrupt Climate Change Conference)


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