Glaciers and climate change: Interview with Gino Casassa

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By Jimmy Langman

Editors Note: The following is from Issue 16.
The impacts of climate change on Patagonia’s glaciers are intensifying as we begin 2018. In November, an unusually large, house-sized iceberg measuring 350 by 380 meters (1,150 by 1,250 feet) split off from the Grey Glacier in Torres del Paine National Park making world news. Not long after, a tragic mudslide on Chile’s Carretera Austral occurred at Villa Santa Lucia, left 18 people dead and destroyed more than two dozen homes. The cause? At least in part, melting glaciers in the mountain above the town.
Scientists say Patagonia’s glaciers are shrinking at a proportionally faster rate and at higher altitudes than anywhere else in the world. Research data in the Patagonian ice fields show that from 2000 to 2012 the rate of thinning was more than double what it was from 1975-2000 and the trend only continues. Altogether, Patagonia’s two ice fields account for about 10 percent of the total sea-level rise caused worldwide by mountain glaciers. "Patagonia is kind of a poster child for rapidly changing glacier systems," says Cornell University researcher Michael Willis, lead author of a study in 2012 that states the Patagonian icefields are supplying water to sea-level at a comparatively high rate for their size and concludes “the ice fields are undergoing rapid drawdown.”
Six years ago, twelve scientists from Chile, Canada, Europe and the United States sent a letter to Chile’s government warning that it must move faster to address threats posed by increasing deglaciation in the country, which is home to more than 90 percent of the Patagonia region’s ice fields. “As the landscape responds to climate and global changes, the time for action is running out,” said the letter. “The glacial risks in Patagonia carry economic and social implications. They will not only affect the landscape, but the infrastructure and people as well.”

Since then, not much has really changed. For instance, Chile has failed to pass a law to protect glaciers, which has been bogged down in the nation’s congress since 2006. And not nearly enough has been done to safeguard communities in the direct line of potential Glacial Lake Outburst Floods (Glofs), or landslides such as what occurred at Villa Santa Lucia.
The last time I was in touch with Gino Casassa, a glaciologist, I was working on a story about the dangers of Glofs in Patagonia and worldwide. In particular, I wanted to know then about his work studying Lago Cachet 2, the most notorious case concerning Glofs in Patagonia. Since April 2009, about three times annually, this five-square-km (2-sq-mile) glacial lake in Chile’s Aysén region has been draining some 200 million cubic meters of water – the equivalent of 46,000 Olympic-sized swimming pools –into the Colonia and Baker rivers. The results are so-called “river tsunamis,” as the Glof events are sometimes called, which can threaten roads, bridges, farms as well as the town of Caleta Tortel at the mouth of the Baker River.
Casassa, 59, who is also an avid mountaineer and rock climber, currently works at Geoestudios in Santiago and as a researcher at the University of Magallanes in Punta Arenas. He has been studying glaciers in Patagonia for more than three decades, with more than 15 scientific expeditions to the Patagonian Icefields since 1984. But he is not just one of Chile’s leading glaciologists, he is a leader worldwide in glacier and climate change issues.
In 2007, Casassa was lead coordinating author of Working Group II for the Fourth Assessment Report of the United Nations Intergovernmental Panel on Climate Change (IPCC), an organization which that same year shared the Nobel Peace Prize with former United States Vice-President Al Gore. The report assessed the “scientific, technical and socio-economic information concerning climate change, its potential effects, and options for adaptation and mitigation.” Most recently, he was co-researcher for a three-year study by the International Atomic Energy Agency about climate change and its impact on glacier retreat and ecosystems in polar and mountain regions worldwide. Here are excerpts from my interview with Casassa in December.
LANGMAN: Are Glacial Lake Outburst Floods (GLOFs) still an issue of concern at Lago Cachet 2 and elsewhere in Patagonia?
CASASSA: If you look at all of Patagonia, we have evidence of more frequent events for the very simple reason that with global warming the ice is melting faster and these glacial lakes are growing. There’s evidence from very remote areas where nobody’s living, like the Cordillera Darwin in Tierra del Fuego and Gran Campo Nevado. There’s at least three cases in the Southern Patagonian Icefield. And in the Northern Patagonian Icefield, there’s also several cases reported. One, of course, is Cachet 2, whose glacial tunnel is still open, but in the past also at Lago Leones, and just south of Glacier Colonia at Lago Arco.
Is Chile prepared for GLOF events?
There’s a gap in the science world right now. We need to do more to map the danger zones and bring this to policymakers, city planners and others to make adequate legislation to regulate the urbanization of towns and roads. This is very well developed in other mountainous countries such as in the Alps - where you have green zones, yellow zones, and red zones - but here it’s not very well developed.
Are you encouraged by the way the world - other than Donald Trump, of course - is reacting to the climate change threat?
Yeah, absolutely. I recently saw the new documentary by Al Gore, An Inconvenient Sequel. It’s wonderful to hear how the world in general is turning to renewable energy sources and prices of solar panels are dropping. This is completely changing the energy matrix, including in Chile, which is actually a major example in Al Gore’s movie.
How much is sea level rising?
Sea level rise is increasing by about 3 millimeters per year. It’s not much, but when you multiply it by 100, over the last century, we have had a sea level increase of about 20 to 30 centimeters, and the projections by the end of this century is it could be even more than 2 meters every year. This figure is increasing and increasing. And 2 meters is a lot.
Is the rate of glaciers melt continuing to increase in Patagonia?
Yes, yes. We just submitted with some colleagues a paper to a journal where we compare more recent surface elevation data from 2014 from a German satellite, Tandem X, with the NASA Space Shuttle Data from the year 2000. It points to further acceleration of the mass loss of many glaciers. On the other hand, we also discovered a few glaciers that are stable. Moreno is stable; it has pulses of both advance and retreat. And surprisingly there are a few other glaciers that are increasing, particularly on the southwestern and central western sides.
Why are glaciers growing in some places?
An increase in precipitation. There’s good evidence that shows the westerlies are increasing and pushing toward the south. As long as that happens, the precipitation will increase as well. As long as that precipitation is solid, and there’s snow, the glaciers will be in good shape and gain mass. But once the warming continues, of course the solid precipitation turns into rain, and rain will melt the glaciers even further.
Do you have any future projections for the Patagonian Icefields?
We have a model on future behavior evolution of the Northern Patagonian Icefield. We’ve not done that exercise yet for the Southern Icefield. But the difference between the North and South is that precipitation has decreased down to around Coyhaique, but further south it has increased. Not much, but a little. And that little will help glaciers to grow in the upper areas, but in the lower areas, where the temperatures are having an effect, the ice melt is increasing. Particularly, there are a few glaciers - very large glaciers like Jorge Montt, O’Higgins, and others - where the ice flow is accelerating. These glaciers are not just melting, but calving - breaking into big pieces and going into the ocean, fjords, or fresh water lakes.
Could we see a major change in the Patagonian landscape in the next century?
Yes, the so-called ice dynamic effects will become more important as the ice melts where there already is a lot of water. This water acts as a lubricant to the glacier flow, so as the ice becomes more lubricated it will flow more rapidly and the ice velocities will become faster. And these calving contributions to the fjords and fresh water lakes will increase. We’re seeing that already not only in several large Patagonian areas, but also Greenland and parts of Antarctica. And there’s no upper limit to the acceleration a glacier can experience, they could flow faster and faster. So that’s a major concern.
The major losses then are in the areas where there is calving?
Yes, the major losses have been occurring close to sea level, but now we’re starting to see glacial losses even above a thousand meters in elevation, so that’s quite remarkable and concerning, that even in the upper plateau, like west of Fitz Roy, we’re seeing glacier loss in a place which is supposed to have snow year round.
When was this discovered?
The Chilean army invited some of our colleagues this past August. They collected valuable data, and what was very remarkable, a stake we had put in there at the end of the 1990s, and which was practically buried under snow when we were last there seven years ago, now has surfaced again. So, the surface melt is increasing, and the snow is not accumulating there. It’s losing snow. So that’s very concerning because the mass ice balance on the Patagonian Icefields, even at that altitude, at around 1500 meters above sea level, is losing mass.
What should Chile and Argentina do to protect the Patagonian Icefields?
I think a major step was done years ago when both countries declared the ice fields as national parks. Industrial use of the parks is legally unacceptable, so they are protected. Argentina has gone a step further in approving a glacier law. In Chile, we’re still lacking a glacier law. What’s needed now is more environmental restrictions, protocols and regulations. We’re working on that - both in Chile and in Argentina - but there’s still a long way to go.



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