Argentina’s Retreating Turbio Glacier Creates a New Lake

Turbio Glacier is at the headwaters of Argentina’s Turbio River and flows into Lago Puelo. The glacier descends east from the Chile-Argentina border at 1,500 meters, descending into a low-slope valley at 1,300-1,000 m.

From 1986-2018 this glacier like many others nearby has retreated substantially leading to development of a new lake. Wilson et al. (2018) noted a substantial growth in the number of lakes in the Central and Patagonian Andes due to the ongoing rapid retreat. Masiokas et al. (2008) reported that significant warming and decreasing precipitation over the 1912–2002 interval in the region. Harrison et al. (2018) observed the number of glacier lake outburst floods have declined despite the increase in lakes.

Turbio Glacier retreat from 1986 to 2018 in Landsat images. Red arrow is 1986 terminus location, yellow arrow 2018 terminus location, and pink arrow glacier across the border in Chile.

In 1986 the glacier terminated at the southeast end of a buttress at the junction with another valley (red arrow in the image above). The glacier was 4.3 kilometers long and was connected to a headwall segment that extends to 1,500 m. There is no evidence of a lake at the terminus of Turbio Glacier.

Across the divide in Chile, the glacier, seen with a pink arrow in the above image, has a length of 3 km. In 1998 the retreat from 1986 has been modest and no lake has formed at Turbio. Across the border in Chile the glacier has divided into two sections.

Turbio Glacier retreat from 1998 to 2017 in Landsat images. Red arrow is 1986 terminus location, yellow arrow 2018 terminus location and pink arrow glacier across the border in Chile.

By 2017 Turbio Glacier has retreated exposing a new lake. The glacier is essentially devoid of retained snowpack, illustrating the lack of a significant accumulation zone that can sustain it. Across the border in Chile the glacier has nearly disappeared with the lower section revealing a new lake and little retained snowpack indicating it cannot survive.

By 2018 Turbio Glacier has retreated 1.3 km, which is over 30 percent of its total length in 32 years. The glacier is separated from the headwall glacier, which can still shed avalanches onto the lower glacier. It is possible that with additional retreat another lake will be revealed in this valley. The substantial retreat here is comparable with that of nearby Argentina glaciers such as Pico Alto Glacier and Lago Cholila . The retreat is greater than on Tic Toc Glacier to the southwest in Chile.

Turbio Glacier in a Digital Globe image from 2013. Red arrow is 1986 terminus location, yellow arrow 2018 terminus location, blue arrows show glacier flow, and pink arrow indicates glacier across the border in Chile. The border is also indicated.

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What the Yak Herders of Northern Bhutan Are Saying About Global Warming

A recent study in the high-altitude Kingdom of Bhutan indicates climate change may have its yak herding population on thin ice. Owing to its topography, the Himalaya provides for a variety of climatic conditions and human populations to study. This diversity makes indigenous peoples who inhabit those areas uniquely qualified to provide traditional knowledge, empirical evidence, and perspective.

This new study, published in Mountain Research and Development, seeks to evaluate vulnerabilities of the yak herding livelihood; no fancy instruments, no ice cores required, just people talking to people who have seen a place change over a long period of time.

New study shows how Yak herders from Bhutan perceive how climate change will impact their culture and livelihoods (Source: Deanne June Scanlan/Twitter).

One hundred village elders, averaging 60 years of age, were chosen as the survey subjects. The researchers from Bhutan’s Ministry of Agriculture and Forests set out on foot in late summer 2017 to gauge the elders’ awareness of environmental changes as well as their perceptions of climate change signals, weather patterns, water and vegetation changes, and economic impacts. The elders offered keen, spatio-temporal perspectives for the researchers who aimed to measure perceptible changes in climate.

Study sites in major yak herding communities were selected in the districts of Thimphu, Bumthang, Paro, and Wangdue. The elders were interviewed in a two-stage sample, and results of the questionnaire were averaged across the population. Survey questions were pretested and framed as closed-ended with three possible responses: “agree,” “disagree,” and “neither.” The conclusions drawn from the results provide a snapshot of a corner of the world at a tipping point.

The yak herding elders’ observed warming over the past 15 years concurs with climate-research data. Data, often measured from a distance and at brief moments in time, can lack salience when presented alone. But when compared next to the testimony of observant, indigenous people, like the yak herders, the data carries greater weight and texture.

The elders observed the increase in temperature, glacial retreat, and an ascension of the snow line. They noted that weather events like flash flooding have become increasingly unpredictable and severe. A majority of respondents said that the frequency of landslides has also increased, though they were divided on the increase of glacial lake outburst floods, a catastrophic consequence of receding glaciers.

Yak foraging the pristine Lhotse Moraine (Source: Flickr)

The herders have observed changes not only in the weather and the natural environment, but also in the health of the animals on which their livelihoods are centered. The yak themselves are sensitive to warm temperatures— illness and discomfort have increased as a result. The elders’ responses showed the researchers that the declining health of the yak and a shift in timing of the migration have made herding more difficult.

Ruijun Long, a yak expert and ecological and pastoral specialist at the International Centre for Integrated Mountain Development (ICIMOD), told GlacierHub that due to warming and glacial meltwater availability, the yak herders can remain on the summer pastures longer than before.

But a warmer, longer summer of grazing doesn’t necessarily translate to happier yaks.

With thick black hair, yaks are well adapted to the cold temperatures of the high Himalaya. Warmer temperatures cause physiological stress in yaks and general health decline. Their grazing spaces have also been encroached upon thanks to the upslope proliferation of warm-climate plants like the rhododendron. With less grass available, yak milk production has suffered. To make matters worse, predators like the snow leopard have been forced into bolder descents due to their melting habitat.

Transhumant migration has become difficult for yak with rising temperatures (Source: Ian Cochrane/Twitter).

Though yak herders are few in number, herding is the lifeblood for a majority of inhabitants in Bhutan’s high Himalaya. To provide additional income for the yak herders, in 2004 the government gave them explicit collection rights to harvest cordyceps, a valued element in traditional Chinese medicine.

According to Tashi Dorji, a senior ecosystems specialist and Bhutan’s “Godfather of Conservation,” the fungi are complicit in luring yak herders away from yak herding. Dorji told GlacierHub “With good market price, the income from this high value commodity has encouraged yak herders to invest in alternative livelihood in downstream-away from yak farming.” Though now the cordyceps themselves are in doubt due to the changing climate.

A cordyceps, or “caterpillar fungus,” emerges from a larva (Source: Jason Hollinger/Flickr).

Dorji cited another pressure forcing rapid transformation of yak herding in  Bhutan: education. While primary schools are common in yak herding villages, young farmers are forced to migrate downstream for higher education. Dorji told GlacierHub, “This already distances younger generation of herders from their landscape and their traditional farming knowledge. Coupled with inherent difficulties and lack of socio-economic development amenities in those landscapes, young herders are less attracted to yak farming.”

The researchers offered a reduction in herd size as a potential adaptation strategy for the yak herders. A smaller herd equates to reduced income, less security and more hardship. While harvesting prized cordyceps is offsetting losses in yak productivity in the interim, a long-term strategy will likely need to include alternate economic opportunities.

As temperatures advance, the hardships will grow. Hardly a country in the world has contributed less atmospheric emissions than Bhutan. And yet it is populations like the yak herders who suffer from climate change first, and most. External forcings like globalization increases might lure yak herders into exploring other ways of subsistence. As northern Bhutan becomes increasingly connected to the world and the yak herding livelihood continues to be threatened, their way of life will remain tenuous.

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Will Climate Change Be Responsible for More Glacial Lake Outburst Floods?

Image of a Himalayan river bridge that could be swept away in the event of a GLOF from the glaciers above (Source: GRID Arendal/Flickr).

How certain is it that climate change increases the frequency and severity of glacier lake outburst floods or GLOFs? It turns out the answer is complicated and the subject of a new study published in The Cryosphere. Although previous research has examined the nature and characteristics of GLOF events in mountain ranges across the world, this recent study provides the first global assessment of the problems involved in developing a robust attribution argument for climate change and GLOF events.

GlacierHub has covered GLOFs throughout the years including major milestones into understanding their characteristics and an interview with a Peruvian farmer explaining his ongoing lawsuit with a German energy firm over climate risks. However, the GLOFs in this study refer specifically to ones caused by the failure of moraine dams. The formation of these moraine-dammed lakes and resulting GLOFs involve the process of thinning, flow stagnation, and glacier recession. Such moraines often contain a melting ice core built from transported rock debris. And, as stated in the study, “when they fail, large volumes of stored water can be released, producing glacial lake outburst floods.” These floods have already caused hundreds of fatalities across the world, destroying downstream communities and stunting the socio-ecological integrity in their wake.

Evidence of a glacial lake outburst flood in Nepal (Source: Matt W/Flickr).

This study presents an unprecedented global GLOF inventory related to the failure of moraine dams. The motivation behind the focus on GLOFs caused by moraine dams is the clear diagnostic evidence left behind by moraine-dam failures as well as the conventional link between climate change and moraine-dammed lake formation.

Dan Shugar, one of the authors of the study and a geoscientist at the University of Washington Tacoma, explained that these particular glacial lakes don’t tend to reform once they burst. “With ice-dammed lakes that burst, the glacier typically ‘heals’ the breach, and so they can reform and burst again and again,” he said, which allows for clear diagnostic evidence.

Adam Emmer, a fellow author from CzechGlobe, told GlacierHub that the research is the first attempt to link climate change with GLOF patterns on a global level. Christian Huggel, another author and geographer from the University of Zurich, added that this is no trivial task.

“It is reasonable to assume that glacier hazards will increase as the climate warms, and we were somewhat surprised to see that over the past century or so, there has not been a monotonic rise in outburst floods,” Shugar told GlacierHub. “The reality, as usual, is a bit more complicated.”

Aerial image of glaciers in Bhutan at risk of GLOF events in the future (Source: The Ice Age/Twitter).

As simple as it would be to link warming climate to the increased frequency and severity of GLOFs, a number of factors go into a GLOF event. Differences in ground thermal conditions, for example, plus presence or absence of ground ice or permafrost all influence extreme weather. Seismic processes, topography, and glacial history also vary across mountain ranges.

However, as stated in the study, “although we know that GLOFs involve a complex set of dynamics… there must be a relationship here to climatic warming.” The scientists did conclude a lagged time response when it comes to GLOFs and climate change, with outburst flood frequency actually decreasing in recent decades since 1970.

“We suggest that outburst floods will become more frequent in response to contemporary warming, but that there is a lag built into the system,” Shugar explained. Thus, although an attribution of GLOFs to climate change is possible, a suite of factors influencing GLOF occurrence means scientists cannot adequately quantify the attribution as many might hope.

Ultimately, from assessing the timing of climate forcing, lag times in glacier recession, lake formation, and moraine-dam failure, the study predicts an increase in GLOF frequency in the coming decades. But because of the assortment of factors involved in a GLOF event and glacier recession, the study states that GLOF frequency has not fluctuated directly in response to global climate change.

A close connection is certainly present, but the varying response times from mountain to mountain and region to region indicate that the relationship is hidden in messy response time dynamics.Prior to this study, no global database had been created that focused specifically on GLOFs related to the failure of moraine dams. The scientists argue that more studies exploring a global context of GLOFs are necessary to better understand the links to the changing climate and naturally-occurring variability. On the policy level, a better understanding of GLOFs’ relationship to present and future climate change is of great interest at both national and regional government levels due to the devastation potential of these events.

Policymakers are using information on GLOFs to develop early warning systems and small-scale infrastructure projects to mitigate their risks (Source: UNDP Pakistan/Twitter).

This research may also make its way to the courtroom. As Huggel explained to GlacierHub, “The study is certainly very relevant with respect to the ongoing legal case where a Peruvian sued German energy producers for the GLOF risks caused by anthropogenic climate change. In principle, more such court cases could follow.” There is also the question of loss and damages, and whether affected countries could receive compensation (or at least stronger assistance) for the resultant (or potential) damage.

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