Ancient Viruses Awaken as the Tibetan Plateau Melts

Discoveries of microbes locked within the depths of glacial ice are opening an exciting new frontier for scientific research, while also posing an ecological predicament. As climate change causes ice masses to melt worldwide, the re-emergence of ancient bacteria and viruses threatens present day species lacking immunity to these old world pathogens.

Early this year, researcher Zhi-Ping Zhong and a team of researchers discovered 33 viral populations within two ice cores that had been extracted from the Guliya ice cap in the northwestern part of the Tibetan Plateau, in the Kunlun Mountains of northwestern China. The ice dates as far back as 15,000 years ago. All but five of the viral groups are new to science, and about half were predicted to have infected different strains of bacteria, which were also abundant in the ice. 

Researchers trek into the Himalayas to collect ice cores. Credit: Institute of Tibetan Plateau Research, Chinese Academy of Sciences/NASA

The Tibetan Plateau is a vast, high altitude arid grassland home to species like the snow leopard, Tibetan wolf, and wild yak. It is surrounded by some of the world’s highest mountain chains including the Himalayas, the Qilian and Kunlun mountains, and the Karakoram range of northern Kashmir. Shadowed by the world’s two highest peaks, Mount Everest and K2, at an elevation that averages over 4,500 meters, the Tibetan Plateau is known to many as “the roof of the world.” 

To climate scientists, however, the Tibetan Plateau and its crown of peaks is known as “The Third Pole,” since it is home to tens of thousands of glaciers containing the world’s largest non-polar reservoir of ice. These glaciers feed the most renowned Asian rivers, including the Yangtze, Yellow, Mekong, and Ganges which stretch thousands of kilometers into the arid regions of China and Pakistan and supply water to almost a third of the world’s population.

In their paper, which is currently circulating for comment in advance of peer-review, the researchers explain that the shallow plateau core was drilled in 1992 at a depth of 35 meters while the summit core was drilled in 2015 at a depth of 52 meters. The viral populations are quite dissimilar between the two ice cores and are also different at various depths, “presumably representing the very different climate conditions” at the time when the viral particles settled down into the snow to be compacted into ice.

Video from Kevin Bakker: Ice core drilling in Antarctica (circa 2009) for the purposes of studying bacterial community structure.

Though the first reports of microbes being found in glacial ice occurred in the early twentieth century, they were largely neglected until the 1980s when scientists began investigating organisms in an ice core from Vostok, in Eastern Antarctica. This discovery sparked a surge of glacier ice-core sampling at the end of the twentieth century. However, most studies focused on bacterial communities.

Kevin Bakker, an infectious disease modeler at the University of Michigan, studied bacterial community structure in Antarctic water and ice cores in 2008-09. Once his team extracted a core, it was melted down very slowly, “at the room temperature of the icebreaker we were on, so around 40-50 degrees Fahrenheit, to make sure the bacteria were kept alive,” Bakker said in an interview with GlacierHub. “Bacteria pop very easily,” he added, “and we needed them alive to see which organisms were eating the radioactive food we fed them… to see which bacteria were active in the community.” 

But for viruses, the definition of whether they are living or not is a moot point, since the DNA/protein complex (while not technically living) simply takes over its host cell — which most of the time is a bacterium. Zhi-Ping Zhong’s team wrote, “information about viruses in these habitats is still scarce, mainly due to the low biomass of viruses in glacier ice and the lack of a single and universally shared gene for viruses,” which can be used for genome sequencing.

In fact, the authors wrote, “there are only two reports of viruses in glacier ice.” They include the Vostok study, as well as a study that found “tomato-mosaic-tobamovirus RNA in a 140,000-year old Greenland ice core.” Viral genomes from glacier ice have not been previously reported, and “their impacts on ice microbiomes have been unexplored.”

Himalayan glaciers. Credit: NASA Goddard Space Flight Center/Flickr

Moreover, prior to this study, no specific decontamination method existed. In an interview with Vice, Scott O. Rogers, a professor at Bowling Green State University, said “the biomass is so low that anything you contaminate it with on the outside is going to be at much higher concentrations than anything on the inside of the ice core.” Because it is easy to contaminate ancient microbes with modern ones, the researchers developed a new “ultra-clean” method for isolating pure samples from the ice cores. 

The ice cores had been sealed in plastic tubing, covered with aluminum, and transferred at -20 degrees Celsius from the drilling sites to freezers in Lhasa, Beijing, Chicago, and finally to Byrd Polar and Climate Research Center at Ohio State University. In a sub-freezing temperature controlled room, researchers began extracting their samples by first shaving off half a centimeter from the outer contaminated layer of ice. The cores were then washed with ethanol to dissolve another layer, and finally sterile water was used to wash the final half centimeter away.

The pristine inner ice was then methodically melted down and filtered, and steps were taken to identify the virus after extracting the microbial DNA. The virus’s age could be determined by counting the ice layers, just as you would count rings in a tree. To be even more precise, the researchers also dated carbon and oxygen isotopes found in each ice layer.

Layers in an ice core. Credit: Paul Hudson/Flickr

Ancient microbes provide researchers a window into Earth’s evolutionary and climatic past. “We are very far from sampling the entire diversity of viruses on Earth,” Chantal Abergel, an environmental virology researcher at the French National Centre for Scientific Research, told Vice. Unfortunately, glaciers around the world are shrinking at an alarming rate. The Tibetan Plateau itself has lost a quarter of its ice since 1970, so the race is on to collect as much knowledge as possible with what’s left. 

Despite its extreme altitude, the glaciers on the Tibetan Plateau are latitudinally situated to receive a great deal of sunlight, and like the other two, this third pole is warming faster than the global average. In the IPCC special report on the cryosphere, scientists warn that two thirds of its remaining glaciers are bound to disappear by 2100. “This will release glacial microbes and viruses that have been trapped and preserved for tens to hundreds of thousands of years,” wrote Zhi-Ping Zhong’s team.

Tibetan Plateau. Credit: Reurinkjan/Flickr

“At a minimum, this could lead to the loss of microbial and viral archives that could be diagnostic and informative of past Earth climate regimes,” the researchers added. However, “in a worst-case scenario, this ice melt could release pathogens into the environment.” 

This possibility is very real. Bakker pointed out that in 2016, the anthrax virus escaped from a frozen reindeer carcass, killing a 12-year old boy and hospitalizing about twenty others, when permafrost melted in the Siberian tundra. Frozen microbes released through ice melt are still able to reinfect their targets, but while “there are a ton of viruses, only a few actually infect humans,” Bakker explained. Most ancient viruses pose more of a risk to bacteria. Still, it is important not to underestimate the “dangers encased in ice,” Rogers warned in his interview with Vice. 

Zhi-Ping Zhong’s study represents a major advance in the field of virology. It shows how frozen creatures can inform predictions about the types of microbes that may re-emerge with climate warming, and what this could potentially mean for the future of our biosphere. 

Video from Kevin Bakker: Bakker’s research team encounters some friends on their scientific expedition in Antarctica in 2009. Perks of being a scientist!

Read More on GlacierHub:

Video of the Week: First Footage From Beneath Thwaites Glacier

Photo Friday: Thwaites Glacier Bore Hole Drilled

Project Aims to Better Understand “Doomsday” Glacier

Hindu Kush Himalaya Assessment Outlines Potentially Dire Impacts of Climate Change

Glaciers in the Hindu Kush Himalayan (HKH) region are projected to shrink by one-third by the end of the century even if average global temperature rise is held to within 1.5 degrees Celsius above pre-Industrial Age levels, according to the authors of a new comprehensive report, The Hindu Kush Himalaya Assessment

Glacier melt of that magnitude has widespread implications. Nearly two billion people live within the 10 river basins that make up the HKH region, and food produced there is consumed by 3 billion people.

The HKH region is green filled. Major, expansive network of river basins that includes the Ganges, Indus, Yangtze, and Yellow Rivers. (Source: Introduction to the Hindu Kush Himalaya Assessment)

The report is likely the most comprehensive climate assessment of the area: It includes input from over 300 experts, researchers, and policymakers. 

The HKH region, which spans 3.5 million square kilometers, across eight countries, contains two of the world’s highest peaks, Mount Everest and K2

“This is a climate crisis you have not heard of,” Philippus Wester, a lead author of the report, told The New York Times. “Impacts on people in the region, already one of the world’s most fragile and hazard-prone mountain regions, will range from worsened air pollution to an increase in extreme weather events.”

Key Climate Findings

Factors such as climate change, globalization, human conflict, urbanization, and tourism are quickly altering the HKH region, the assessment authors say.

Warming in the HKH region is strongly attributed to anthropogenic greenhouse gases. The authors say that if average, global temperature rise is 1.5°C, the HKH region will see an additional 0.3°C temperature rise. 

In other words: The region could warm as much as 1.8°C even under ambitious efforts to limit human-generated greenhouse gas emissions. And the northwestern Himalayas and Karakoraman expansive mountain range of 207,000 square kilometers that extends from eastern Afghanistan to southern China, could experience at least a 2.2°C temperature rise.

Karakoram Highway with Rakaposhi peak featured in the frame (Source: Shozib ali, Wikimedia Commons)

This warming could lead to increased glacial melt, biodiversity loss, and decreased water availability, the authors say. The Tibetan Plateau, which lies south of the Himalayas, will likely face decreased snow cover as temperatures rise. Elevation-dependent warming is a major contributor to the geographic changes in this region.

Other future climate changes include increased frequency of extremely warm days and decreased frequency of extreme cold ones.

The State of the HKH Cryosphere

The Hindu Kush Himalaya cryosphere is comprised of glaciers, snow, ice caps, ice sheets, and permafrost. Future temperature changes will influence the timing and magnitude of meltwater runoff. The report’s authors find that snow-covered areas will decrease and snowline elevations will rise.

Bhagirathi Peaks, Garhwal Himalaya (Source: Richard Haley, Flickr)


Loss of glacial volume in the region will increase runoff and the size of glacial lakes, resulting in a higher potential for Glacier Lake Outburst Floods, or GLOFs, and other hazards. Thawing permafrost is also expected to continue, resulting in the weakening of mountain slopes and peaks.

Messages to Policymakers

“Climate change impacts in the mountains of the HKH are already substantive. Increased climate variability is already affecting water availability, ecosystem services, and agricultural production, and extreme weather is causing flash floods, landslides, and debris flow,” according to the assessment’s authors.

Without immediate mitigation and adaptation policies, they conclude that the region’s glaciers—and therefore Hindu Kush Himalaya residents—face extraordinary threats.

Read More on GlacierHub:

Mapping and Monitoring Glaciers in the Hindu Kush Himalaya

Ice Loss, Gravity, and Asian Glacier Slowdown

Photo Friday: Marc Foggin & the Mountains of Central Asia

Video of the Week: What Glacier Melt Means for Humpback Whales

In our Video of the Week, marine biologists examine how climate change might impact humpback whales in the waters off the coast of Chile. Melting Patagonian glaciers add freshwater to the ocean ecosystem, which is likely to change the water’s chemical composition, threatening the food supply of humpbacks.

Climate change is already affecting humpback migration patterns in other parts of the world. And changing climate conditions around Svalbard, Norway is altering the habitat of white whales.

The video, shared by the AFP news agency, emphasizes the importance of protecting vulnerable, marine ecosystems.

Researchers utilized buoys to gather information. Buoys can be useful in measuring such things as temperature, salinity, and pH levels, which can help monitor ecosystem changes and make projections about future conditions.

Check out more news on GlacierHub:

Millennial Climate Effects on a Lake Ecosystem in Southern Chile

GLOF Risk Perception in Nepal Himalaya

Argentina’s Retreating Turbio Glacier Creates a New Lake

Video of the Week: Cascading Glacier Melt in Northern Pakistan

Our Video of the Week takes place in a remote mountainous region of northern Pakistan. The video, shared by the World Meteorological Organization, was shot by a villager from the Ghizer district, which is located in the Gupis Valley in Baltistan. Glacier melt and snow is seen descending from a nearby valley, alarming residents.

Northern Pakistan is home to over 5,000 glaciers. The region is particularly vulnerable to climate change, with an increasing number of glacial lakes forming in mountain valleys in recent years. The melt is likely coming from the nearby Baltoro Glacier, one of the longest nonpolar glaciers in the world. Many of these glaciers are melting rapidly due to climate change, posing a great threat to nearby mountain communities. 

Discover more news on GlacierHub:

An Impossible First: Colin O’Brady Completes Solo Trek Across Antarctica

A Survey of the UNESCO Andean Glacier Water Atlas

Erasmo Glacier, Chile Terminus Collapse and Aquaculture

A Survey of the UNESCO Andean Glacier Water Atlas

UNESCO recently published a report which addresses the effects of global warming on the glaciers of the Andes. The Andean Glacier and Water Atlas examines the changing climate patterns across western South America, as well the historical and projected rates of retreat of important glaciers in the region. Increased melting will impact societies reliant on glaciers for water resources. The eventual loss of glaciers presents a challenge for countries to address.

An aerial view of the Ojo del Albino glacier in Argentina (Source: Andrew Shiva/Wikimedia Commons)

The Andes are the longest continental mountain range in the world, spanning the western edge of South America through several countries. These mountains are considered to be the water towers for the surrounding populations. They provide water to about 75 million people living within the Andes region and 20 million downstream along surrounding rivers. The Andes continue to have a significant influence on local cultures and economies. The impending loss of these glaciers may cripple dependent communities, industries, and various sectors across South America.  

Key Messages and Future Projections

The atlas identifies several key messages essential for discerning the changes in the Andes. Projections indicate that temperatures in the tropical Andes could increase between 2°C and 5°C by the end of the 21st century. The recent IPCC SR1.5 report emphasized the devastating effects of just 1°C of warming, such as extended periods of drought and extreme global heat events. The Andes will likely experience increasingly hotter years with warming driving further glacier retreat.

The report notes that changes in precipitation are harder to project than temperature changes. Nonetheless it presents serious concerns for some regions across the Andes. The atlas refers to the IPCC for precipitation projections. In the southern Andes region, precipitation will greatly decrease by the end of the century, including Chile and Argentina in particular. These regions will likely experience drought events, and loss of glaciers may be devastating to the environment and its people.

Scientists have also observed rapid retreat in glaciers in the tropical Andes, as well as lower-altitude glaciers. According to the atlas, one glacier which remains in Venezuela will likely disappear by 2021. Many large tropical glaciers exist in Peru, including Quelccaya Ice Cap, which may disappear by 2050 at the current rate of warming. Glaciers are also quickly retreating in Bolivia, Chile, and Argentina. This retreat and volume loss of glaciers is “locked in,”and glaciers will continue to retreat no matter what. Even with a moderate level of emissions, the IPCC projects that barely a fifth of the glaciers will remain by the end of the century, with some reduced to barely 3 percent of their current size.

Pico Humboldt, the second highest peak in Venezuela, is home to the country’s last glacier (Source: Okty/Wikimedia Commons)

Impacts of Retreating Glaciers

The loss of glaciers and glacial meltwater is inevitable. As warming continues, a majority of glaciers will soon experience “peak water” (which occurs when melting exceeds new mass accumulated by snowfall), likely within the next 20 years. Many tropical Andes glaciers already reached peak water in the 1980s and have been outputting less water since. Although many countries will benefit from peak water, the aftereffects of less meltwater outflow will heavily strain the available water supply.

Bolívar Cáceres, a specialist of the tropical Andes who worked on the atlas, told GlacierHub about some of the effects of glacier retreat and possible methods for adapting to water scarcity. “One of the indirect effects of long-term melting in communities is the reduction of visitors. Since glaciers no longer exist in some places or become very difficult to climb, tourists are currently opting out and most likely will go to other places in the future,” he said. This will affect local economies that depend on tourism flow and the resources generated. As for adaptation, Cáceres believes that promoting technologies in agriculture and livestock areas to better manage water resources is essential for sustainability.

Water quality will also be affected by the loss of glaciers. Bryan Mark, an expert on Andes and Peruvian glaciers, added: “Recently glacier-free landscapes feature lots of unconsolidated materials that tend to result in more sediment laden, erosive, and ‘flashy’ discharge streams.'” Sediment pollution presents a number of problems for the water supply, including degrading the quality of drinking water for locals and their livestock. Mark also highlighted the importance of diversifying water reservoir resources, utilizing groundwater, small dams, and precipitation capture as alternate water resources.

Vibrant houses and high-rises in the Andean city of La Paz, Bolivia (Source: Matthew Straubmuller/Flickr)

Efficacy and Practicality of Policy Recommendations

The atlas examines the significance of glacier retreat on communities. It provides policy recommendations for countries to sustainably secure future water availability. Some examples include implementing preventative measures for natural glacier-related hazards and developing climate services for water resource management. Although these recommendations are intended to provide direction towards sustainable water supply management, there are concerns of clarity, implementation, and effectiveness of these policies.

Dirk Hoffmann, an expert on glaciers in high mountain ecosystems, commented on the effectiveness of the policy recommendations on communities. “The policy recommendations are all very interesting, but on the whole seem to be somewhat too general as to be useful to specific decision maker,” he said. Hoffmann views the recommendations as well intended and believes the atlas to be effective in raising awareness of these issues. In a practical sense, however, they are too far removed to help decision makers, he said. A clear indication as to whom these recommendations are directed towards would be beneficial.

Deeply entrenched valley below the tree line, with a small town at the river’s edge (Source: UNESCO)

Mark Carey, an expert of the Peruvian Andes, shared similar thoughts on the effectiveness of these recommendations. Carey stated that the lack of social science and humanities research on vulnerability and unequal impacts of shrinking glaciers is an issue. “Vulnerability is framed in ways to conceptualize homogenous ‘affected populations,’ such as those in agriculture or urban areas, rather than understanding the complicated social divisions and power imbalances embedded in the diverse social groups,” he said. Carey added that although the science is necessary, the complex human dimensions of climate change adaptation are essential.  

The Andean Glacier and Water Atlas recognizes the importance of improving interactions between science and policy, bringing awareness of key issues surrounding the loss of glaciers in the Andes. This is a major step towards successful adaptation; climate scientists, social scientists, and policymakers will need to collaborate to effectively allocate resources for sustainable management of the challenges associated with glacier retreat.

Roundup: Antarctica’s Glacier Loss, Girls on Ice, and A New Glacier Model

Antarctica’s Glacier Melt Is More Extensive

From Proceedings of the National Academy of Sciences: Antarctica’s ice is melting at an accelerating pace—six times the melt rate four decades ago—and that could have significant consequences for coastal communities around the world. The Antarctic shed 40 billion tons of ice each year between 1979 and 1989. But researchers say that the southern continent has been shedding 252 billion tons of ice each year since 2009.

“I don’t want to be alarmist,” Eric Rignot, an Earth systems scientist for both the University of California, Irvine, and NASA, who led the work, told The Washington Post. “The places undergoing changes in Antarctica are not limited to just a couple places,” said Rignot. “They seem to be more extensive than what we thought. That, to me, seems to be reason for concern.”

Read the study here.

Researchers from UCI and NASA JPL recently conducted an assessment of 40 years’ worth of ice mass balance in Antarctica, finding accelerating deterioration of its ice cover (Source: Joe MacGregor/NASA).


Inspiring the Next Generation of Women Scientists

From Inspiring Girls Expeditions: Offering free, wilderness excursions for high school-aged girls, Inspiring Girls Expeditions aims to foster curiosity about the natural world and methods of scientific inquiry. Since 1999 University of Alaska, Fairbanks glaciologist Erin Pettit has led over a dozen “Girls on Ice” trips to Washington’s South Cascade Glacier.

Pettit founded the program because “I wanted to share the inspiration, curiosity, and excitement of using science to learn and explore the mountains. In turn, the girls have taught me about the dreams, and challenges, and amazing variation of lives and experiences for girls from all different communities and cultures across the world.”

Upcoming Girls on Ice expeditions include trips to the Gulkana Glacier in Alaska, Washington’s Mount Baker, the Asulkan Valley in British Columbia, and the Findelen Glacier in Switzerland.

Find out more about Inspiring Girls Expeditions here.

A “Girls on Ice” expedition (Source: Inspiring Girls Expeditions).


A New Tool for Modeling Glacier Flow

From The Journal of Chemical Physics: Bo Persson, a theoretical physicist at the Jülich Research Center in Germany, has developed an improved model of glacier flow. Persson said his model improves understanding of the cavities that form between ice and bedrock and how water fills these cavities and becomes pressurized.

Persson’s past work has focused on rubber friction and adhesion. “I could take knowledge I have gained during maybe 10 or 15 years of studies of other friction and quickly apply it to the glacier friction problem,” he told the CBC.

The model could help improve estimates of how much glacier melt is contributing to sea level rise around the world.

Read more about Persson’s new model here.

Theoretical physicist Bo Persson has developed an improved model of glacier flow. (Source: Multiscale Consulting)

Are Melting Glaciers Putting Arctic Fish at Risk?

Shifts in Capelin Fish Feeding Ecology

An important Arctic fish might be in trouble. A recent study in Greenland examines changes in the feeding ecology of capelin, a small forage fish in the smelt family. Melting glaciers are affecting its diet, and this change in diet can heavily influence its growth and reproduction. This could spell trouble for the other animals that eat capelin.

Found in the Arctic, Capelin are an important food source for marine mammals such as whales and seals. Atlantic cod, a major commercial fish species, are one of its major predators. Atlantic puffin also like to feed on them, along with other sea birds.

A puffin enjoying a mouthful of what appears to be capelin (Source: Lawrence OP/Flickr).

Capelin enjoy feeding on plankton, microorganisms that float in the sea and on freshwater. Krill, small shrimp-like crustacean, are also crucial in the diet. Capelin seem to migrate less than other species, making them extremely dependent on the food that’s readily available to them. Any major changes in food availability can ripple through the Arctic food web.

The Godthåbsfjord in West Greenland was sampled at a number of sites, all the way from the mouth where it opens to the ocean to the furthest inland basin. Capelin were sampled by the researchers during the months of May and August, when increased meltwater from summer heating flows into the fjord. The fish were then divided into 2-cm interval size groups, assessing for differences in age. Researchers carefully dissected the stomachs and intestines, preserving them so that they could later examine their contents to determine diets over different locations and times.

Lorenz Meire talks about the framework of the study in an interview with GlacierHub. Meire is a marine scientist at the Royal Netherlands Institute for Science Research and one of the scientists behind this study. “By trawling in a sub-Arctic fjord impacted by glacial meltwater, we aimed to assess the change in capelin size distribution and its diet throughout the season,” he says. Meire adds that scientists tried to link diet with observed changes in zooplankton biomass and environmental conditions.

Three small capelin on tin foil (Source: Rodrigo Sala/Flickr).

What are some observed environmental changes?

Studies show a shift in abundance of krill from freshwater-influenced regions toward the oceans. We see similar shifts with large plankton. GlacierHub spoke with Kristine Engel Arendt, a marine biologist from the University of Copenhagen. Her research on plankton community structure is referenced in the study. She provides some insight on how runoff from the exit glacier and high up ice sheets affect the ecosystem ecology, looking particularly at smaller plankton species.

Arendt told GlacierHub that the fjord typically experiences a bloom of algae in the spring, which is a food source for plankton. The addition of freshwater from the late summer runoff initiates a second bloom of algae, driven by an upwelling of nutrients. “The marine food web is closely linked to the energy source from the algae bloom, and therefore zooplankton species that can utilize food over the entire summer period are favored,” she says. These smaller species of plankton benefit from the nutrients. They use this extra algae bloom during the summer to grow and reproduce. This observation indicates an abundance of smaller plankton at the inner basin region in August. Stomach examinations show a clear increase of small plankton in the diet of fish from this area of the fjord.

Drifting Ice, Godthåbsfjord, West Greenland (Source: Lorenz Meire).

Arendt points out that climate change effects such as melting glaciers are not always negative. We see that this inflow of freshwater is in fact beneficial to these smaller plankton. But how might this change affect capelin?

A Disadvantage to Younger Capelin

It’s important to look at the migration and reproductive pattern of capelin to understand the impacts. Maturing adult capelin spawn from April to June in the fjord, from the inner basin to near-coastal regions. Studies show that all male capelin and some females die off with connection to spawning. Researchers can then presume that the May sample will consist of both mature and immature capelin, and August will be dominated by young capelin. This is reflected in the findings of the study.

The beautiful fjords of Greenland (Source: GlacierHub author Arley Titzler)

The quality of the available food sources must also be examined. It differs with plankton size. Larger plankton species are relatively richer in fat per unit of weight. This makes them more ideal for energy intake and growth than the smaller plankton species. Energy intake and growth is particularly critical for young capelin. Meire told GlacierHub, “If smaller copepods (plankton) become more abundant, they will form a more important food source for capelin. Though this can impact the energy transfer as small copepods in the diet cannot compensate for the absence of larger copepods and krill.”

Lack of the more favored species in the inner regions can negatively affect nutrition of capelin. Younger capelin here are at risk. They will need to feed on the larger, fat-rich plankton to receive enough nutrients to effectively grow and reproduce. This can greatly affect the Arctic food web.

Roundup: Ice-cliff Instability, Buffers, and Glacial Retreat

Future Acceleration of Antarctic Ice Sheet Retreat

From Nature: “Marine ice-cliff instability (MICI) processes could accelerate future retreat of the Antarctic Ice Sheet if ice shelves that buttress grounding lines more than 800 meters below sea level are lost. The present-day grounding zones of the Pine Island and Thwaites glaciers in West Antarctica need to retreat only short distances before they reach extensive retrograde slopes. When grounding zones of glaciers retreat onto such slopes, theoretical considerations and modelling results indicate that the retreat becomes unstable (marine ice-sheet instability) and thus accelerates. It is thought that MICI is triggered when this retreat produces ice cliffs above the water line with heights approaching about 90 meters.”

Discover more about how marine ice-cliff instability could accelerate future retreat of the Antarctic Ice Sheet here.

A massive crack extends across the  Pine Island Glacier in 2011. (Source: NASA).


Glacier Melt Reduces Buffer Capacity

From Waters Resources Research: “Glaciers store large amounts of water in the form of ice. They grow and shrink dominantly in response to climatic conditions. In Central Asia, where rivers originate in the high mountains, glaciers are an important source for sustainable water availability. Thus, understanding the link between climate, hydrology, and glacier evolution is fundamental. Some instruments mounted on satellites are capable of monitoring glaciers. However, the potential of these sensors is limited by technical constraints that will affect the availability and precision of the products. In order to overcome these shortcomings and investigate glacier dynamics, we use a numerical model that represents the relevant processes of the hydrological cycle with a very fine spatial and temporal resolution. Our results show that glaciers buffer extreme weather conditions to provide sustainable river flow. This functionality is put in jeopardy due to the currently observed glacier retreat, in the Pamir Mountains.”

Read more about how glaciers buffer against river runnoff here.

Image of ice-covered mountains in the distanc
The Pamir Mountains are a mountain range in central Asia (Source: Allan Grey/Flickr).

How will Asia’s Glaciers React to Increases in Global Temperature?

From Nature: “Glaciers in the high mountains of Asia (HMA) make a substantial contribution to the water supply of millions of people, and they are retreating and losing mass as a result of anthropogenic climate change at similar rates to those seen elsewhere. In the Paris Agreement of 2015, 195 nations agreed on the aspiration to limit the level of global temperature rise to 1.5 degrees Celsius ( °C) above pre-industrial levels. However, it is not known what an increase of 1.5 °C would mean for the glaciers in HMA. Here we show that a global temperature rise of 1.5 °C will lead to a warming of 2.1 ± 0.1 °C in HMA, and that 64 ± 7 per cent of the present-day ice mass stored in the HMA glaciers will remain by the end of the century.”

Learn more about the impact of climate change and increasing temperature on Asia’s glaciers here.

Map showing glacial loss under a 1.5ºC increase in global average temperature
This map shows regional temperature increases and projected glacial area (Source: Kraaijenbrink et al. ).

Glacier Melt Threatens Medicinal Plants in Pakistan

Lack of access to health facilities is a massive problem facing developing countries. Zaheer Abbas et al. recently published a paper on the Karakoram Range in Northern Pakistan in which the communities have been relying on traditional methods for treating common physical ailments. Like many remote communities without access to modern health care, the Balti community have honed their traditional knowledge of local plants over the centuries using herbal treatments readily available to them in the Karakoram range. However, traditional knowledge is not well recorded in the region because medicinal plant concoctions are only passed down orally. This knowledge, if documented and shared, could inform other non-traditional medicine, according to Abbas et al. However, as R. Jilani et al. describe in another paper, if glaciers in Northern Pakistan start to melt, the reduction in the water resources could greatly affect the plants grown in the region, threatening the future use of Balti knowledge.

A map of the Karakoram Range (Source: Creative Commons).

The Karakoram Range, a large mountain range that spans across Pakistan, Afghanistan, China, India, and Tajikistan, is one of the most glaciated areas outside of the polar regions and also one of the most botanically diverse. The range is home to the Biafo Glacier, which is the third largest glacier in the Karakoram and the fourth largest in Asia. For now, as Abbas et al. explain, the glaciers in the Karakoram Range are stable and not experiencing glacier melt like other regions. This is due to the very high altitude of the glaciers and the fact that temperatures remain cold throughout the year. However, a paper by Rajiv Chaturvedi et al. explains that in climate scenarios where carbon emissions continue to increase, we can expect melting of the Karakoram glaciers to occur at a rapid rate. The region and its glaciers have not previously been studied in depth due to the area’s remoteness, high altitude and harsh climate. Adding additional complications to future research is the fact that there is no weather station in the region, so temperature readings typically come from Skardu, 55 km away. This raises questions about the future impact of climate on the use of medicinal plants and traditional Balti knowledge.

A picture of Thymus Linearis (Source: Dinesh Valke/Creative Commons).

For their Karakoram study, Abbas et al. interviewed 69 inhabitants of the region, including five herbalists, in order to understand how regional plants are used by the local communities for medicinal purposes. As Abbas et al. explain, many modern drug discoveries have been based on medicinal plants used by indigenous people. For this study, the team explored a total of 63 plant species, and with the help of the Balti people, categorized the plants into uses for 11 common diseases and disorders. They also looked at  how effective the plants were at resolving those particular health issues based on a scale of 1 to 5 (5 being most effective). The common health issues ranged from anything from a common toothache to kidney stones. The study also showed the diversity of the plant parts used in the remedy, including flowers, seeds, leaves, and in some cases, the entire plant. The majority of the species studied were indigenous to the Tormik Valley due to its microclimate. The Tormik Valley is lush and fed by freshwater streams and springs.

A photo of Hippophae Rhamnoides (Source: Jean Tosti/Creative Commons).

Of the 63 species examined, three of them were particularly valuable due to their effectiveness, and each scored a 4 or 5 on the scale. Thymus linearis (a shrub with small dark purple blooms), commonly known as Himalayan thyme or common thyme and belonging to the Mint family, is used by the Balti people to treat abdominal pain and vomiting. Hippophae rhamnoides, commonly known as sea-buckthorn (a tree with bright orange seeds) is used to treat a multitude of disorders, including arthritis pain, eczema and urinary disorders. Convolvulus arvensis, a winding weed and relative of the morning glory, when ingested as a whole plant, is used to treat constipation.

A photo of Convolvulus Arvensis (Source: Farbenfreude/Creative Commons).

Interestingly, Abbas et al. share that the upper and lower parts of Northern Pakistan have unique ethnobotanical traditional knowledge. The communities in the neighboring Skardu valley, located at the junction of the Indus and Shigar Rivers, for example, use the same Thymus linearis plant to treat colds and pneumonia. While they may use similar plants depending on the availability, communities sometimes use the plants in different ways. In some cases, they may use plants for activities beyond food and medicine, such as for building huts and fences.

Ethnobotany, the study of interactions between humans and plants, is especially important now as the documentation of traditional knowledge decreases with time. The Balti community demonstrates how important traditional knowledge of plants can be. The traditional knowledge cultivated within these communities can provide important data to help inform health care policy. However, if melting begins to affect the glaciers in the Karakoram Range, these plants may be entirely destroyed.

Precipitation Controls Retreat of Kerguelen’s Glaciers

An aerial view of the Kerguelen Islands and its glaciers (Source: NASA Earth Observatory)
An aerial view of the Kerguelen Islands and its glaciers (Source: NASA Earth Observatory)

Islands in the Indian Ocean are not the first to come to mind when glacier retreat is mentioned. However, glaciers in the Kerguelen Islands, located at sub-polar latitudes in the southern hemisphere, have been experiencing widespread and rapid retreat in recent years.

While rising temperatures are generally assumed to be the main cause of glacial retreat, a recent study published in Nature revealed that a reduction in precipitation is the dominant factor controlling the retreat of glaciers in the Cook Ice Cap on the Kerguelen. Similar conclusions were made in a study of Kilimanjaro’s melting glaciers, and this study could offer further insight into the effect of circulation changes on glaciers.

A Macaroni Penguin, one of thirty bird species that nest on the Kerguelen Islands (Source: Magnus Manske).
A Macaroni Penguin, one of thirty bird species that nest on the Kerguelen Islands (Source: Liam Quinn/Wikimedia Commons).

The Kerguelen Islands are among the most isolated places on Earth. Located on the seaway between South Africa and Antarctica, they are only accessible by boat and serve as a nesting ground for many bird species, such as the Macaroni Penguin. Glaciers cover about 500 square kilometers of the islands, and the loss of ice from these glaciers was among the most serious in the world in the 2000s, according to the study mentioned above.

Uncertainty surrounding the effects of climatic changes on glaciers in the southern mid-latitudes is particularly high due to a lack of observational data on glaciers and ice caps. Along with a lack of full modeling studies, this has led to the general assumption that warming is the main driver of glacial loss, as is the case in the northern mid-latitudes.

A team of scientists led by Vincent Favier, a researcher at Université Grenoble Alpes, set out to test the hypothesis that glacial retreat on the Kerguelen was largely due to increasing temperatures. The Cook Ice Cap was a suitable site for study because it is mainly made up of glaciers, which links its mass variations more strongly to climate variations than other ice caps at similar latitudes. In addition,  the availability of long term climate and glaciological observations in the region made it possible to produce accurate models of glacial mass balance from 1850-2011.

A glaciologist uses a steam drill to make a hole in the ice of the Cook Ice Cap to set up an ablation stake (Source: Vincent Favier).
A glaciologist uses a steam drill to make a hole in the ice of the Cook Ice Cap to set up an ablation stake (Source: Vincent Favier).

Using a combination of field data, satellite data, and climate and glacial models, the team was able to attribute 77% of ice loss since the 1960s to atmospheric drying, with temperature increases only amplifying the losses. The researchers used the decade between 1950 and 1960 as a reference period for glacial mass and modelled changes in glacial mass using different hypothetical temperature and precipitation values.

1000 different simulations were run, revealing that dryness is the dominant influence on glacier wastage despite the increase in temperatures in the Kerguelen since the 1960s. The dominant influence of precipitation is particularly evident in glacier mass balance trends between 1963-1975, when both temperatures and mass balance increased. This seemingly paradoxical observation was due to higher levels of precipitation experienced during this period.

Precipitation over the Kerguelen is influenced by the north-south movement of wind belt in the middle latitudes of the Southern Hemisphere – the Southern Annular Mode (SAM). It brings stormy weather to the Kerguelen when it is in a more northerly position, also known as its negative phase. Since 1975, the SAM has been in southerly positions more frequently, increasing atmospheric dryness over the Kerguelen. This is associated with ozone layer depletion and increases in greenhouse gas emissions, suggesting that the frequency of positive phases of SAM is likely to increase over the course of the century and worsen glacier retreat in the Kerguelen.

The terminus of a glacier at the southern end of Cook Ice Cap (Source: B. Navez)
The terminus of a glacier at the southern end of Cook Ice Cap (Source: B. Navez)

Darker surfaces exposed by this loss of glacial ice could exacerbate melting in what is known as the ice-albedo negative feedback mechanism. These surfaces absorb more heat than light colored surfaces like ice, amplifying the effects of temperature changes on glacier loss.

As the SAM is a hemispheric feature, other glaciers within similar latitudes may also have been affected. As Favier explained in an interview with GlacierHub, “We chose this location because we believe it is an example of what is occurring under the same latitude but at other longitudes, in particular in New Zealand… Indeed, this drying trend is suggested at a large scale in the mid latitudes.” However, the lack of long-term sets of observational data for other locations at similar latitudes makes it difficult to determine possible effects, he said.

The difficulty of determining the effects of these changes on other locations within similar latitudes is exacerbated by the poor simulation of temperature and precipitation patterns over the Kerguelen in climate models used by the Intergovermental Panel on Climate Change. 95% of the models used by Favier and his colleagues to model patterns of glacial mass loss in the Kerguelen underestimated glacial mass losses at Cook Ice Cap. As such, projections of ice losses in the southern mid-latitudes based on model simulations should be used with great caution, particularly in areas where circulation changes are expected.

While glacier retreat is usually associated with increasing temperatures, it seems that circulation changes are important too. Remote locations like the Kerguelen Islands can offer clues about some of the impacts of climate change.

Peru Faces Tensions Over Water

Pastoruri, Peru. Image by Taco Witte/Flickr
Pastoruri, Peru. Image by Taco Witte/Flickr

Peru will face a “new normal” as greater agricultural and energy demands, population growth and climate change chip away at what is left of its glaciers, according to a recent article in the Yale Journal of International Affairs. Glacial retreat could ultimately lead to conflict in the country, the author found.

“Peru offers an early view of the challenges mountainous regions worldwide may face in coming decades,” wrote Peter Oesterling, the author. “The country—if successful—may also provide the world a model for effective policies to mitigate threats to environmental and human security.”

For people in Peru, glaciers are the essence of their existence. Most people live on the west coast, an arid region, and rely on glacier meltwater for day to day use, crops, hydroelectric power and mining. But since the early 1980’s, Peru’s glaciers have shrunk by more than 22 percent. Further loss could lead to increased risk of flooding and water scarcity as well. Already, seven out of nine watersheds in the Cordillera Blanca are already past “peak water,” meaning that the glaciers have passed the upper limit of melt water they can release.

At the same time, water demand in Peru is on the rise as water security dwindles. The population is projected to grow by 35 million by 2020, which will put pressure on the country’s existing land and water resources. Millions of households rely on the  Cañon del Pato hydropower plant on the Rio Santa, but as water availability declines, the plant could lose 40 percent of its power generating capability.

The country’s mining industry also consumes a great deal of water. Eleven percent of Peru’s land is being mined for minerals. In addition to using water for mineral extraction, mining releases contaminated water back into the watershed.

View to Tocllaraju Summit, 6036m. Photo by Twiga269/Flickr
View to Tocllaraju Summit, 6036m. Photo by Twiga269/Flickr

“Peru’s trends in water use and supply are incompatible,” wrote Oesterling. “Glacially-fed rivers are already at emergency levels—insufficient for the country’s agricultural and hydroelectric demands during the dry season.”

The result has been socio-environmental tensions in the country, which have roots in the country’s history. Peru’s government historically cut indigenous communities off their land and limited their access to water resources for the sake of economic development. Still now local populations are dis-empowered and unable to take part in any decision making processes on their land even though they are the first to suffer from water contaminated by mining. Oesterling discusses a protest in which angry villagers blocked a major highways for several days, even though they were physically attacked by police, in order to bring attention to the concerns over pollution from mines.

To prevent future conflict, the country will need better regulatory processes that shifts the responsibility of environmental impact assessments away from private companies and into the hands of government bodies, said Oesterling. Existing regulatory government bodies could also benefit from being strengthened.

“With a sound response that addresses clean water access, environmental protection, and public participation in resource allocation decision-making, Peru can mitigate the effects of glacial recession and acclimate to new environmental realities,” he concluded. “Yet—much like Peru’s water supply—the time for effective action against glacial recession is dwindling—and quickly.”

Life on the Edge: The Science of Glaciers that Meet Oceans

Tidewater glacier on Antarctic coast (source: Jason Auch/Flickr)
Tidewater glacier on Antarctic coast (source: Jason Auch/Flickr)

In an October 2015 article in Earth & Space Science News, David Holland and Denise Holland suggest steps to increase the understanding of glacier melt to improve projections of sea level rise.

IPCC (Intergovernmental Panel on Climate Change) reports have concluded that anthropogenic causes are to blame for glacier retreat in the last century. They predict that increased melt in the present century will rise global sea levels. The authors report that the contribution of the West Antarctic Ice Sheet, alone will change low-lying coastal and communities worldwide and threaten marine ecosystems.

They note that the rate of sea level rise will be influenced by a number of factors, including the local shifts in the gravitational pull of land masses, along with changes in water currents, wind patterns, and water temperature and salinity. The rebound of land masses, once the weight of glaciers and ice sheets is removed, will also influence sea levels.

Map of Antarctica (source: Maximilian Dörrbecker [Chumwa])
The complex nature of the interface between ice sheets and the ocean also creates uncertainty about the future of many of the West Antarctic glaciers, as it is difficult to make predictions of how the ice will react in the future. In one possible scenario, the circulation of warm ocean waters that is currently held off by continued cold meltwater runoff from Antarctica could grow larger, and the cold water barrier would no longer block it from teaching the continent. The warm water would thus be able to make direct contact with the underside of the glacier and warm it from below, greatly increasing the glacier melt.

Holland and Holland note that many problems with predicting the effects of West Antarctic glacier melt stem from a deficit of data. Though satellites are able to measure glacier volume, they are unable to observe the water resting underneath glaciers or the land mass upon which some glaciers rest. Another area of difficulty in predicting the melting of the West Antarctic glacier involves a shortfall in scientific understanding of calving—the process in which the section of a glacier front breaks and falls into the ocean. Scientists compare the difficulties of constructing models of calving to the challenges of predicting earthquakes. They remain unable to make long-term predictions about when they will occur.
Sketch of the Antarctic coast showing interactions of ice sheet, glaciers and oceans. (Source: Hannes Grobe, Alfred Wegener Institute for Polar and Marine Research, Bremerhaven, Germany )

Holland and Holland state that in order to create accurate predictions for the contributions of the West Antarctic Ice Sheet to sea level rise, scientists need to couple glacier and ocean models. Currently there is little cooperation between glaciologists and oceanographers, even though both work on sea level rise since each uses separate models specific to their disciplines. To address this problem Holland and Holland report, the World Climate Research Programme (WCRP) has established a project, Climate and Cryosphere (CliC). This project held a meeting in October 2014, in which the Marine Ice Sheet–Ocean Model Intercomparison Project (MISOMIP) was established. The project seeks to draw on the efforts glaciological and oceanographic modelers. The participants in the project work together to create coupled and interactive glacier-ocean models. The goal is to follow this suite of glacier-ocean models with regional simulations of specific outlet glaciers such as those found in West Antarctica.

Holland and Holland say that scientists, by coupling glacier and ocean models, can greatly improve the accuracy of future sea level rise projections attributed to the West Antarctic Ice Sheet and its outlet glaciers. Because of the increasing threat of sea level rise to communities around the world, the accuracy of such projections is of great value. It is to be hoped that this importance will support efforts to produce these projections, which require increased cooperative effort between nations and between disciplines.