Grounding Lines of Antarctic Glaciers Show Fast Retreat
From Nature Geoscience, “Grounding lines are a key indicator of ice-sheet instability, because changes in their position reflect imbalance with the surrounding ocean and affect the flow of inland ice. Although the grounding lines of several Antarctic glaciers have retreated rapidly due to ocean-driven melting, records are too scarce to assess the scale of the imbalance. Here, we combine satellite altimeter observations of ice-elevation change and measurements of ice geometry to track grounding-line movement around the entire continent, tripling the coverage of previous surveys. Between 2010 and 2016, 22%, 3% and 10% of surveyed grounding lines in West Antarctica, East Antarctica and at the Antarctic Peninsula retreated at rates faster than 25 m yr−1 (the typical pace since the Last Glacial Maximum) and the continent has lost 1,463 km2 ± 791 km2 of grounded-ice area.”
Discover more about Antarctica’s melting situation here.
Glacier Melt Exposes Land for Methane-Oxidizing Bacteria
From Oxford Academic: “Methane (CH4) is one of the most abundant greenhouse gases in the atmosphere and identification of its sources and sinks is crucial for the reliability of climate model outputs. Although CH4 production and consumption rates have been reported from a broad spectrum of environments, data obtained from glacier forefields are restricted to a few locations. We report the activities and diversity of Methane-Oxidizing Bacteria along a Norwegian sub-Arctic Glacier Forefield using high-throughput sequencing and gas flux measurements. The overall results showed that the methanotrophic community had similar trends of increased CH4 consumption and increased abundance as a function of soil development and time of year when glaciers retreat.”
Read more about the relationship between methane and glacier retreat here.
Grazing Patterns in Glacier-fed Wetlands
In PLOS ONE, “Grazing areas management is of utmost importance in the Andean region. In these harsh mountains, unique and productive wetlands sustained by glacial water streams are of utmost importance for feeding cattle herds during the dry season. After the colonization by the Spanish, a shift in livestock species has been observed, with the introduction of exotic species such as cows and sheep, resulting in a different impact on pastures compared to native camelid species—llamas and alpacas. Our results suggest that the access to market influenced pastoralists to reshape their herd composition, by increasing the number of sheep. They also suggest that community size increased daily grazing time in pastures, therefore intensifying the grazing pressure.”
Explore the influence of glacier meltwater on wetland size and herd composition here.
Anomalous Stable Glaciers in the Karakoram Mountains
From Climate Dynamics: “Glaciers over the central Himalaya have retreated at particularly rapid rates in recent decades, while glacier mass in the Karakoram appears stable. To address the meteorological factors associated with this contrast, 36 years of Climate Forecast System Reanalyses (CFSR) are dynamically downscaled from 1979 to 2015 with the Weather Research and Forecasting (WRF) model over High Mountain Asia at convection permitting grid spacing (6.7 km). In all seasons, CFSR shows an anti-cyclonic warming trend over the majority of High Mountain Asia, but distinctive differences are observed between the central Himalaya and Karakoram in winter and summer.”
Read more about the climatic differences between the central Himalaya and Karakoram here.
Microbial Differences of Two Andean Lakes
From Aquatic Microbiology: “The limnological signatures of Laguna Negra and Lo Encañado, two oligotrophic Andean lakes which receive water from Eucharren Glacier and are exposed to the same climatic scenario, were driven by the characteristics of the corresponding sub-watersheds. The abundance of phototrophic bacteria is a significant metabolic difference between the microbial communities of the lakes which is not correlated to the Chla concentration.”
Read more about microbial differences of two Andean lakes here.
Carabid Beetles in Norway
From Norwegian Journal of Entomology: “Nine species of carabid beetles (Coleoptera, Carabidae) were pitfall-trapped during two years in an alpine glacier foreland of southern Norway. A two-year (biennial) life cycle was documented for Nebria nivalis (Paykull, 1790), N. rufescens (Ström, 1768), and Patrobus septentrionis Dejean, 1828. This was based on the simultaneous hibernation of larvae and adults. In P. septentrionis, both larvae and adults showed a considerable activity beneath snow. A limited larval material of Amara alpina (Paykull, 1790) and A. quenseli (Schönherr, 1806) from the snow-free period indicated larval hibernation. A. quenseli was, however, not synchronized with respect to developmental stages, and its life cycle was difficult to interpret.”
Read more about the ecology of carabid beetles in an alpine glacier foreland here.
This week, learn how religion and climate change intersect in Peru through “Fire and Ice on the Mountain,” a short documentary film by independent filmmaker and American University professor Bill Gentile.
The Huaytapallana mountain glaciers are the main water source for the Huancayo people during the melting season and spiritually significant during the Andean New Year. With the glacier melting in recent decades, the local government has doubled its conservation efforts. In the documentary, Gentile and Swedish anthropologist Karsten Paerregaard team up to find out how the melting of the glaciers impacts the Peruvian communities and their spiritual connection.
The availability of water under ever-increasing climate stress has never been more important. Nowhere is this more apparent than in glacial mountain regions where runoff from glaciers provides water in times of drought or low river flows. As glaciers retreat due to climate change, the water supplied to these basins will diminish. To better understand these hydrological changes, a recent study published in Nature Climate Change examined the world’s largest glacierized drainage basins under future climate change scenarios.
Expansive in scale, the study differentiates itself from previous research that assessed the hydro-glacier issue at more localized scales like specific mountain ranges, for example. This study analyzes 56 glacierized drainage basins on four continents excluding Antarctica and Greenland. The basins examined were selected based on their size: they needed to be bigger than 5,000 km2, in addition to having at least 30 km2 of ice cover and greater than 0.01 percent of total glacier cover during the chosen base period of 1981 to 2010.
The motivation behind the study’s global scale, the first ever completed, according to Regine Hock, one of the study’s authors, is that “at a local scale you can only cover a fraction of the glaciers/catchments that may be relevant.” She told GlacierHub that while there are advantages to local studies because they can be more detailed and accurate, the advantage of a global study is that spatial patterns across regions can be identified and analyzed.
In order to calculate changes in glacial mass and accompanying runoff, defined as water that leaves a glacierized area, the authors utilized the Global Glacier Evolution Model to simulate relevant glacial processes including mass accumulation and loss, changes in glacial extent, and glacier elevation. The glacier model was driven by three of the IPCC’s Representative Concentration Pathways (RCP). These are future greenhouse gas (GHG) concentration scenarios based on different socio-economic pathways. The RCP’s chosen by the authors were the 2.6 scenario, which they note is the most similar to the 2015 Paris agreement, the 4.5 scenario where GHG concentrations stabilize by 2100, and the 8.5 or “business-as-usual” scenario where GHG concentrations continue to increase past 2100.
How do these three scenarios impact glacial volume in the study’s glacierized basins? After running the glacier model, total volume was projected to decrease in all three with a decrease of 43±14 percent for the 2.6, 58±13 percent for the 4.5, and 74±11 percent for the 8.5, respectively.
A decrease in glacial volume will in the short term mean an increase in water for a basin as runoff increases, that is until the point of “peak water,” where the amount of glacial runoff begins to decrease as glacier volume declines. Distressingly, peak water has already been reached in 45 percent of the basins examined in the study including most of the Andes, Alps, and Rocky Mountains.
Three factors— total glacial area, ice cover as a fraction of the basin, and the basin’s latitude— influence the timing of peak water occurrence in a basin. Basins with many large glaciers at higher latitudes like in coastal Alaska were projected to reach peak water near the end of the century whereas basins closer to the equator with small glaciers like the Peruvian Andes have already experienced or will soon experience peak water. Furthermore, the Himalayas are projected to experience peak water around mid-century as their high elevation tempers the effect of their relatively low latitude.
The study also examined changes to glacial runoff on a monthly timescale for the years 2050 and 2100, focusing specifically on the melt season from June to October in the Northern Hemisphere and December to April in the Southern Hemisphere. The monthly results showed spatial consistency, which surprised the authors, according to Hock, with runoff increasing in almost all basins at the beginning of the melt season (June/December) and decreasing toward the end (August and September/February and March). Another unexpected finding was the significant reduction in overall runoff, up to a 10 percent decrease by 2100 in at least one month, in basins with very low glacial cover, a phenomenon that was observed in a third of the basins, Hock added.
It is important to remember that these changes in basin runoff mean more than just changing numbers and statistics: there are people and communities that rely on water provided by glaciers. The authors note that 26 percent of the Earth’s land surface is covered by glacierized drainage basins, impacting a third of the world’s population.
The ramifications of glacier retreat will not be felt equally across the basins observed in this study. When asked what regions are most at risk, Hock identified both the Andes and Central Asia as places of concern. In the Andes, runoff is decreasing in almost all basins. This is of particular concern due to the limited water resources of the South American west coast. In Central Asia, glaciers contribute to basin runoff in all months, leading to potential problems if runoff is significantly reduced.
These regions, along with other glacier reliant places, face an uncertain and atypical water future, one that will likely see an increase in glacial runoff, followed by a sharp decline.To prepare for these forthcoming challenges, further study is needed, particularly with a focus on the human dimensions of glacial retreat.
Human activities have drastically reduced the natural habitats of Polylepis, a rare genus of tree species that dominates the high-altitude forests of the Andes and can grow from an elevation of 3,000 meters close to the glacier line, at approximately 5,000 meters above sea level. A recent analysis by Beatriz Fuentealba and Steven Sevillano of reforestation efforts of Polylepis in Ancash, Peru, has highlighted the importance of local communities for the successful implementation of these activities.
The analysis, published in the book Beyond Restoration Ecology: Social Perspectives in Latin America and the Caribbean, focused on the project “Conservation Corridor of Polylepsis in the South of Los Conchucos” that was implemented by the non-governmental organization, the Mountain Institute. The project was developed in 2004 for a period of five years to preserve, restore and recover the Polylepsis forests— or queñuales, as they are known in the Peruvian Andes— of the southern area of Conchucos in the Ancash region. This new study makes the results of the project available to a wide readership.
The Ancash region, located in the northern part of Peru, is known for the Cordillera Blanca mountain range, which runs through the region and preserves the largest reserve of tropical glaciers in the world. Polylepsis forests located in this area have received protection from the national government since 1975 when Huascaran National Park was created. The protection of the national park was strengthened in 1977 when UNESCO recognized it as a biosphere reserve.
Queñuales are a type of Andean forest ecosystem. Manuel Peralvo, a researcher at the regional NGO CONDESAN, told GlacierHub in an interview that these ecosystems generate multiple benefits that are key for the well-being of Andean communities including hydrological regulation, reduction of risks of natural hazards and long-term maintenance of Andean biodiversity.
As Beatriz Fuentealba told GlacierHub, Polylepsis forests in the Cordillera Blanca help store soil water and maintain a moist environment throughout the year. She explained that queñuales are important for water regulation because the roots of these species support the infiltration of water into the soil. The abundant leaf litter that the queñuales produce allows for more water storage and improves soil nutrients. These forests also support the protection of puquios, or water springs, situated near local communities.
Moreover, Fuentealba pointed out that queñuales also generate a distinct microclimate. As a result, they become a biodiversity refuge. “Inside queñualesthere is less solar radiation, more moisture and extreme temperatures are attenuated,” she explained. This microclimate allows for the development of particular mosses and other plants that do not grow in other areas. Several bird species also depend on the natural resources located in these forests.
Steven Sevillano told GlacierHub that queñuales are recognized as islands of biodiversity. In addition, he pointed out that in a climate change scenario they will be key for high-Andean biodiversity conservation. For this reason, the disappearance of queñuales would not only indicate the loss of a rare species but also the loss of habitat for several other species that use these forests as a refuge.
Unfortunately, the queñual populations have sharply declined due to logging for firewood, clearing for pasture for ranching and other activities. In 1978, before the Mountain Institute implemented the project, several reforestation efforts had been developed. One of these initiatives was initiated by Pompeyo Guillen, a park ranger in Huascaran National Park, who promoted the planting of queñuales with the support of the population living in the surrounding areas. National government programs contributed to this initiative with food in exchange for the labor provided. In the last 20 years, private mining companies established in the region have further supported these activities by paying a wage to people who take part in reforestation work.
The project “Conservation Corridor of Polylepsis in the South of Los Conchucos” sought to reach conservation agreements with local communities. Thus, it established ways for the project to support an increase in economic development of the local communities working on reforestation efforts. These conditions included cattle breeding, tourism promotion, and the improvement of local education. In exchange, the communities would propagate, reforest and preserve queñuales.
“Participating in reforestation activities is not easy, it requires effort, time and attention in order to increase the success of the reforestation,” Sevillano told GlacierHub.
Despite these difficulties, such efforts allow participants to become engaged with conservation projects and to recognize the importance of these forests. They take care of them and appreciate them more because they also start to value their own efforts, he added.
Fuentealba indicated that the challenge of working with communities is understanding the reasons that each local community has for participation in reforestation initiatives, which leads them to participate in these activities. Furthermore, the approach of particular reforestation projects to include local populations differs.
Considering these experiences, the study suggests that a strategy to ensure the sustainability of reforestation projects of queñuales involves increasing the awareness of the benefits provided by queñuales, as well as connecting local communities with their natural resources.
When working in restoration efforts, it is not only relevant to understand the degradation level of the forests. It is also important to connect with local populations and comprehend how they will be impacted, their relationship with these ecosystems, and their values. Such participatory projects can reduce negative community impacts on forests while supporting positive ones.
This op-ed originally appeared on WashingtonPost.com and was produced by The WorldPost, a partnership of the Berggruen Institute and The Washington Post.
When the poisoned river ran red with heavy metals, people from nearby communities didn’t believe at first that climate change was to blame. In this small village nestled in the Cordillera Blanca, a majestic mountain range that contains several of the highest peaks in South America, the glaciers melted and metal-rich rocks were exposed to the air for the first time in thousands of years.
The glacial meltwater washing over the exposed rocks carried metals such as lead, arsenic, cadmium and iron into area waterways, turning rivers like the Rio Negro a rust red. This contaminated both soil and water and posed a significant health risk. Over time, people, wildlife and livestock who drank the water became sick, and crop productivity plummeted.
As headlines of global climate change become more alarming, it’s easy to forget that climate change is also an intensely local problem. Startling statistics announcing that the snowcaps of the Andes or Alps will disappear before the end of this century conceal the fact that hundreds of smaller glaciers in these mountain ranges have already melted away, leaving a trail of devastation and threatening thousands of families’ way of life.
In Peru, the government conducted a national inventory in 2013 and found that between 1970 and 2003, the 19 Peruvian mountain ranges with glaciers lost around 40 percent of their total ice surface. Some very large glacier ranges have already lost a third of their perennial ice, and some smaller glaciers no longer exist at all.
Silently, climate change has started to leave a trail of disasters in these mountains, and that has consequences for major lowland cities that rely, knowingly or not, on mountain ecosystems for food and water, agriculture and livelihoods. In a place like Peru, climate change adaptation begins in the mountains. And alpine communities are scrambling to find ways of adjusting to a new reality.
In the remote mountain villages around the Rio Negro, that adaptation effort took a curious and innovative form. To restore the poisoned river water and contaminated landscape around it, villagers collaborated with scientists from the Mountain Institute and with academic specialists. With training, they built a water purification system that collects the acidic river water in small ponds. Then, using local traditional knowledge, they planted native plant species that could absorb metals from the water.
Involving the communities on the front lines of climate change in this way is vital to finding concrete solutions to local problems; the open dialogue and collegial relationship with the scientists empowered the local community, sparking a palpable sense of pride in both local traditions and scientific solutions to complex climate problems.
And it wasn’t the only time traditional knowledge helped restore a landscape degraded by climate change.
In the Nor Yauyos-Cochas Reserve of central Peru, Guadalupe Beraun, a wise and respected grandmother from the small village of Canchayllo, was showing me around the parched pastures where her sheep and cattle used to graze. The mountain peaks towered darkly above us. A small glacier called Wacra used to glisten there, a blinding white against the dark mountain and blue sky beyond. But year after year, it receded, finally disappearing completely around 1990.
Once the glacier was lost, the wetlands started drying up, and sheep and cattle had to be moved down the mountain to pastures that still had a few ponds. Wild vicuna, a relative of llamas, also had to migrate elsewhere. I asked Guadalupe what these drastic, local changes have meant to her. She paused and said, “It’s changed my whole way of life. When I walk here now, I long to see vicuna in the grasslands, like before. I used to sing to them to show my happiness and gratitude to this place.”
Where Guadalupe lives, people have relied on glacial meltwater to supply their alpine wetlands and grasslands, known as the puna, for as long as anyone can remember. The puna ecosystem extends from around 13,000 feet to 16,000 feet, a belt of pastures above the tree line and below the glaciers. Traditional ways of making a living at this high altitude rely on a healthy ecosystem. Villagers raise sheep, cattle and alpaca and also sheer wild vicuna for their valuable wool. Local farmers grow native potatoes and lesser-known tubers such as oca, olluco and mashua as well as corn, quinoa, broad beans, squash, fodder crops and much more. Their food and water security has always depended on glacial meltwater.
As glaciers receded, dozens of villagers like Guadalupe left their highland pastures years ago and began to over-exploit grasslands at lower elevations. But those pastures, too, were only going to last a few years. Locals were well aware that the puna would continue to degrade, livestock would suffer, and the ecosystem itself would eventually collapse. A more permanent solution — a sustainable adaptation to climate change — had to be found.
Together with scientists from the Mountain Institute and the National Agrarian University in Lima, villagers from Canchayllo and nearby Miraflores planned a “back-to-the-future” solution. Instead of re-inventing the wheel, they chose to honor their ancestors’ impressive engineering by restoring ancient, local infrastructure that was used to regulate water in the puna.
The water management systems developed in ancient Peru involved a set of technologies designed to slow or retain water in high alpine territories. The purpose was to keep water available for use as long as possible in the dry season. These ancient systems included dams and reservoirs of different sizes, irrigation canals and large silt traps that kept soil from being eroded in years of intense rain. They also encouraged wetlands to develop. The excess soil in these silt traps could be “harvested” and used in terraces in warm valleys below the puna.
Pre-Inca civilizations in the Andes maintained highland pastures with water technologies that slowed the movement of water through grasses and soils and provided a buffer against flooding and drought. Local wildlife flourished. A steady supply of water supported lush pastures and livestock, who in turn provided manure, used as fertilizer for corn, tubers, hard grains and the hundreds of potato varieties that are native to mountain valleys in the Andes.
Over the centuries, most of this infrastructure was abandoned. Today, older villagers only remember some of the locations and uses. The social and demographic collapse of indigenous cultures after the Spanish conquest of Peru in 1532 helps explain why these ancient socio-technological systems decayed. In more recent times, glacier retreat, changes in precipitation, loss of local labor and shifts away from traditional herding and farming practices have all contributed to the abandonment of this infrastructure and the degradation of the puna ecosystem.
But that’s starting to change. Villagers and scientists worked together to restore some of the ancient canals, and the wetlands began coming back to life. Cattle and sheep graze once again in revitalized highland pastures. The approach once again produced a strong sense of pride that traditional knowledge was being used to enable the community to become more resilient to the impacts of climate change.
The disappearing glaciers of the tropical Andes are our preview of what climate change has in store for mountain communities as well as the millions of people in lowland areas whose livelihoods depend on high-elevation ecosystems. We must prepare in our own regions by following the lead of these mountain people and learning from them as agents of change. We should pay close attention; mountains near the equator are our canary in the coal mine. They are the Earth’s thermometer — an early indicator of a planetary fever.
I am hopeful and inspired by the mountain communities that live at the foot of receding glaciers. Their creativity, tenacity and resilience come from their deep trust in nature and their kinship with the mountains that surround them. They can teach all of us how to start adapting to a future without glaciers.
German Court to Hear Peruvian Farmer’s Climate Case Against RWE
From The Guardian: “A German court has ruled that it will hear a Peruvian farmer’s case against energy giant RWE over climate change damage in the Andes, a decision labeled by campaigners as a ‘historic breakthrough.’ Farmer Saul Luciano Lliuya’s case against RWE was ‘well-founded,’ the court in the north-western city of Hamm said on Thursday. Lliuya argues that RWE, as one of the world’s top emitters of climate-altering carbon dioxide, must share in the cost of protecting his hometown Huaraz from a swollen glacier lake at risk of overflowing from melting snow and ice.”
Impacts of Rapidly Declining Snow and Ice in the Tropical Andes
From ScienceDirect: “The reduction in water supply for export-oriented agriculture, mining, hydropower production and human consumption are the most commonly discussed concerns associated with glacier retreat, but many other aspects including glacial hazards, tourism and recreation, and ecosystem integrity are also affected by glacier retreat. Social and political problems surrounding water allocation for subsistence farming have led to conflicts due to lack of adequate water governance. This review elaborates on the need for adaptation as well as the challenges and constraints many adaptation projects are faced with, and lays out future directions where opportunities exist to develop successful, culturally acceptable and sustainable adaptation strategies.“
From Nature Geoscience: “Limited measurements along Greenland’s remote coastline hamper quantification of the sediment and associated nutrients draining the Greenland ice sheet, despite the potential influence of river-transported suspended sediment on phytoplankton blooms and carbon sequestration. We find that, although runoff from Greenland represents only 1.1 percent of the Earth’s freshwater flux, the Greenland ice sheet produces approximately 8 percent of the modern fluvial export of suspended sediment to the global ocean. We conclude that future acceleration of melt and ice sheet flow may increase sediment delivery from Greenland to its fjords and the nearby ocean. ”
The glaciers of the Peruvian Andes have long served as a key water reserve in a region where precipitation patterns are highly seasonal and vary greatly from year to year. However, the retreat of these glaciers because of climate change threatens to alter the balance of water resources. A new paper detailing this transformation titled “Glacier loss and hydro-social risks in the Peruvian Andes” was recently published in the journal Global and Planetary Change and has attracted interest from others including the Mountain Research Initiative.
GlacierHub spoke with Molly Polk, one of the authors of the paper, about its findings. Dr. Polk was in contact with three of her eleven co-authors, including Bryan Mark, Kenneth Young and Adam French, all who helped provide feedback to GlacierHub. Their paper examined the effects of glacial retreat on water resources based on the results of long-term research on water access and its impacts on hydro-social risks in Peru. The research focused on how water in the Andes connects both biophysical and social processes to evaluate regional vulnerability to hydrological changes caused by retreating glaciers.
Research for this collaborative project grew in scale and focus over time, according to the authors. In the beginning, the project focused on the impacts of glacial retreat on rural livelihoods within the Santa River watershed near Huaraz, Peru. The initial results pointed to the importance of coupled hydrological and social systems in the region. From there, the project received an award from the National Science Foundation enabling the formation of an interdisciplinary team of eleven researchers with extensive experience in Peru.
The team focused on two areas: the Santa river watershed, which drains the Cordillera Blanca, the most glaciated tropical mountain range in the world, to the Pacific, and the smaller Shullcas River watershed, east of Lima, which drains the Mantaro and Ucayali rivers before joining the Amazon River. Both areas contain mining operations, agricultural regions, and hydroelectric stations, making them ideal to study the impacts of glacial retreat through the lens of biophysical and social processes
Both watersheds have experienced substantial losses in glacier mass in recent years. Observations of the Cuchillacocha glacier in the Santa watershed, for example, show the glacier’s surface area retreated from 1.24 km2 to 0.82 km2 and lost a volume of 0.02 km2, equivalent to a 10-m lowering of the glacier’s surface, from 1962 to 2008. Notably, the authors found their volume-change analyses showed a 37 percent greater loss in glacial mass than what could be projected using surface area measurements alone. These analyses could infer that the region’s glacial water reserves have been overestimated.
Land cover changes within the watersheds were also found to be an important proxy for monitoring glacial retreat. As glaciers recede the bare ground they leave behind is colonized by plants, changing hydrologic flows. This “greening” of land cover causes lakes and wetlands below glaciers to expand during the peak of the melting and shrink thereafter. By analyzing this expansion and shrinkage, the authors were better able to evaluate glacial recession and its impact on water recourses.
To assess the social aspects of water access and glacial retreat, the study first evaluated the perceptions of local water users regarding water availability finding that perception varied across time and space. Most surveyed users perceived declining water availability during the dry seasons, with the greatest awareness of declines among users in areas with the least glacial cover and least awareness in areas with high glacial coverage.
The diversity of water users in the study area was also found to be an important aspect of water accesses and availability. Rural households use water for agriculture and livestock, usually relying on springs and glacial-fed streams. Recent expansion of mining within the watersheds has increased water demand as well as contamination risks. Survey results indicate local residents have negative opinions of mining operations and their effects on water quality and availability. Further downstream, growth in large-scale irrigation for agriculture and hydroelectric production divert large quantities of water from the watersheds. This growth has fostered the development of large water infrastructure projects to meet water demands, like multiple irrigation projects, for example, that divert water from the Santa river for agriculture along the arid Peruvian coast.The authors note that while this infrastructure is economically important, it is also at risk to natural disasters such as earthquakes and weather variability, most notably the El Niño Southern Oscillation that threatens water access.
Water governance in a region experiencing economic development and urban population growth should be a key social priority, but formal action has yet to develop. New watershed management processes were developed in 2010 but failed to take hold due to intra-regional and inter-regional political problems, according to the authors. This lack of governance has led to water scarcity during the dry season and conflicts over water between users. Attempting to remedy the situation, the state has tried to formalize water rights, but this led to differing opinions, with small-scale water users fearful of privatization and large-scale users arguing that water rights will allow for more efficient water usage.
Glacial recession in the Peruvian Andes is increasing the hydro-social risks faced by water users in the region, risks that are likely to only get worse over time. The authors highlighted three challenges to GlacierHub that necessitate future research to better address these risks. First, expanded monitoring of glacier and hydrological changes would aid in detecting changes in water storage. Secondly, the complex interactions associated with local water access need further investigation to better inform water management. Finally, the effects of elements outside of the watersheds, such as the global or regional economy on access to local water resources, needs further examination. Ultimately, the authors were able to examine the transformation affecting glacierized, hydro-social systems through a transdisciplinary approach across both physical and social processes, enabling the assessment of risks and vulnerabilities faced by a diverse group of water users in a rapidly changing region. And while these transformations have the potential to drastically change the region, enthusiasm and dedication still prevail, Dr. Polk says, as people from diverse backgrounds come together to figure out the best way forward.
Glacier Shrinkage Driving Global Changes in Downstream Systems
From Proceedings of the National Academy of Sciences of the United States of America: “Glaciers cover ∼10% of the Earth’s land surface, but they are shrinking rapidly across most parts of the world, leading to cascading impacts on downstream systems. Glaciers impart unique footprints on river flow at times when other water sources are low. Changes in river hydrology and morphology caused by climate-induced glacier loss are projected to be the greatest of any hydrological system, with major implications for riverine and near-shore marine environments… We conclude that human society must plan adaptation and mitigation measures for the full breadth of impacts in all affected regions caused by glacier shrinkage.”
Learn more about the impacts of glacier retreat on water supply across various regions here.
Glacier Inventory and Recent Glacier Variations in the Andes of Chile
From the Annals of Glaciology: “The first satellite-derived inventory of glaciers and rock glaciers in Chile, created from Landsat TM/ETM+ images spanning between 2000 and 2003 using a semi-automated procedure, is presented in a single standardized format. Large glacierized areas in the Altiplano, Palena Province and the periphery of the Patagonian icefields are inventoried… Glacier attributes estimated from this new inventory provide valuable insights into spatial patterns of glacier shrinkage for assessing future glacier changes in response to climate change.”
Discover the distribution of glaciers in Chile and reports on their retreat here.
From the British Society of Geomorphology: “Glacier reconstruction typically aims to establish the former extent of ice masses at any given period. Such reconstructions are important because they provide crucial information about past (palaeo) glacier changes over much longer timescales than the observational record permits. Reconstructing the dimensions and dynamics of palaeo-ice masses enables equilibrium line altitudes, and temperature or precipitation to be calculated, making glaciers an important palaeo-climate proxy. Given this utility, geomorphologically-based glacier reconstructions have been generated for many regions globally, although the specific methods employed are rarely described formally. To address this shortcoming, this chapter describes some of the methods employed in generating geomorphologically-based reconstructions for ice sheets and mountain-scale glaciers (< ~1,000 km2).”
Explore the novel concept of restoring glaciers that have melted (albeit virtually) here.
High in the Bolivian Andes, the pace of glacial retreat is accelerating, which may significantly decrease the amount of glacial meltwater available to streams and aquifers critical to farming communities in the region’s river basins. In addition to the long-term threat posed by glacial retreat, these communities are alsothreatened by economic uncertainty and climatic variability. As a response to livelihood insecurity, many Bolivian farmers choose to migrate, temporarily or permanently, to nearby urban centers. But how exactly are migration decisions understood within these migrant households?
In a recent chapter in Global Migration Issues, Regine Brandt and her team interview farmers in two Andean valleys to understand the factors contributing to migration decisions. The research demonstrates that migration has increased in importance as a livelihood strategy and that rural Bolivians consider environmental factors, social ties and economic needs together when making these decisions.
To obtain these findings, the team conducted research in the municipality of Palca, a high-altitude rural area where 80 percent of the population lives in extreme poverty. They asked members of migrant farming households in two separate glacier-fed river basins to describe any factors that had influenced temporary or permanent migration decisions. In analyzing their data, the researchers looked to the frequency with which each causal factor was mentioned in each interview. If, for example, climate change was mentioned several times as a factor for a household, but social conflict was only mentioned once, climate change was understood to be of greater importance to that household in making their decision.
According to Raoul Kaenzig, one of the article’s co-authors, the impact of glacial retreat on farmers in the Andean highlands is still poorly documented. In the 1980s, Bolivia underwent a severe droughtand has since experienced a rise in the frequency of extreme weather events, as well as a shift in rainfall patterns. In response, some peasants changed their agricultural practices, while others began sending individual family members to urban areas. Internal migrants rarely travel beyond their home region and maintain connections to their rural origins, often spending only part of the year in nearby cities, according to the study. In Bolivia, migration is seen as a means of contributing to the greater household economy— an individual may migrate to find work but with the intention of helping to support the family back home.
In an interview with GlacierHub, Corinne Valdivia, a professor of agricultural economics at the University of Missouri, explained how the threats posed to farmers in this and surrounding regions have increased in recent years. “The production risks have increased in the region of the North and Central Altiplano of Bolivia, as well as in Southern Peru, with longer periods without rainfall, and short and intense rains,” she said. “Pests and diseases have also increased. These threaten the livelihoods of families who are producing for their consumption and for the market. Migration is a strategy to address this, but in turn means that less labor is available to tackle the stresses posed by the changing climate.”
For 60 percent of the regional migrants interviewed in the study, better educational opportunities were the primary driver of their migration decision. Additionally, nearly every respondent pointed to an increasingly unpredictable climate as a factor in their migration. Individuals living near the Illimani glacier, which has become a symbol of climate change in Bolivia, were significantly more likely to emphasize climatic variability, glacier retreat and water problems as factors in their migration than those living near a less iconic symbol of glacial melting, Mururata. The authors attribute this difference to a combination of observable environmental change and discourse.
Unsurprisingly, off-farm work, which is more commonly available in urban areas, has become important in diversifying household income. Of migrants from Mururata, 94 percent were between the ages of 14 and 38, meaning that the onus of migration tends to fall on the most productive members of the household. However, young migrants do not typically return to rural areas. In an interview with GlacierHub, Kaenzig stressed that there are political rootsto this phenomenon. “Since the agrarian reform of 1953, household agricultural land is divided within the family. Therefore, each generation has less agricultural acreage, and eventually, only one family member typically maintains the farm while others migrate in search of alternative income sources,” he said.
Other factors affecting migration decisions include inadequate income, employment opportunities, and farming resources, such as access to water and land. Because the links between climate change and reduced productivity are not always clear to farmers, the authors conclude that environmental factors should not only be understood through statements the farmers make that directly bear on climate change, but also through the economic factors that are distinctly tied to climate change. In an interview with GlacierHub, Regine Brandt, one of the chapter’s co-authors, emphasized the importance of understanding how these stressors work together. “There are no simple explications for causes and effects, nor simple solutions for how to support the farmers to adapt to the effects of multiple stressors. I think that social, technical, political and other factors and their roles as stressors should not be ignored in the debates about climate change adaptation,” she said.
What does the future hold for these communities? Depending on temperature and precipitation scenarios, as well as high-altitude water conservation efforts, millions of people in the Bolivian highlands could be without a continuous source of freshwater in the coming decades, Kaenzig told GlacierHub. But so far, necessary steps are not being taken to prepare for these changes. “Despite wide recognition that rapid retreat of glaciers necessitates the construction and strengthening of existing water reservoirs and dams, few measures have been undertaken in Bolivia,” he said.
The authors conclude with a call to action: impoverished farming communities, both in the Central Andes and other mountainous regions around the world, are in urgent need of support to cope with current and looming climatic instability. According to Brandt, it is only by understanding linkages between migration factors that rural development programs can be adapted to meet the needs of these vulnerable farmers.
From PLOS ONE: “Current glacier retreat makes vast mountain ranges available for vegetation establishment and growth. As a result, carbon (C) is accumulated in the soil, in a negative feedback to climate change. Little is known about the effective C budget of these new ecosystems and how the presence of different vegetation communities influences CO2 fluxes. On the Matsch glacier forefield (Alps, Italy) we measured over two growing seasons the Net Ecosystem Exchange (NEE) of a typical grassland, dominated by the C3 Festuca halleri All., and a community dominated by the CAM rosettes Sempervivum montanum L… The two communities showed contrasting GEE but similar Reco patterns, and as a result they were significantly different in NEE during the period measured. The grassland acted as a C sink, with a total cumulated value of -46.4±35.5 g C m-2 NEE, while the plots dominated by the CAM rosettes acted as a source, with 31.9±22.4 g C m-2. In spite of the different NEE, soil analysis did not reveal significant differences in carbon accumulation of the two plant communities, suggesting that processes often neglected, like lateral flows and winter respiration, can have a similar relevance as NEE in the determination of the Net Ecosystem Carbon Balance.”
Learn more about the colonization of a deglaciated moraine here.
Vegetation and the Serpentine Syndrome
From Plant and Soil: “Initial stages of pedogenesis (soil formation) are particularly slow on serpentinite (a dark, typically greenish metamorphic rock that weathers to form soil). This implies a slow accumulation of available nutrients and leaching of phytotoxic (poisonous to plants) elements. Thus, a particularly slow plant primary succession should be observed on serpentinitic proglacial areas. The observation of soil-vegetation relationships in such environments should give important information on the development of the serpentine syndrome (a phrase to explain plant survival on serpentine)… Plant-soil relationships have been statistically analysed, comparing morainic environments on pure serpentinite and serpentinite with small sialic inclusions in the North-western Italian Alps….Pure serpentinite supported strikingly different plant communities in comparison with the sites where the serpentinitic till was enriched by small quantities of sialic rocks.”
Climate Changes Landscape of South American Communities
From Global Migration Issues: “Mountain regions are among the most vulnerable areas with regard to global environmental changes. In the Bolivian Andes, for example, environmental risks, such as those related to climate change, are numerous and often closely intertwined with social risks. Rural households are therefore characterized by high mobility, which is a traditional strategy of risk management. Nowadays, most rural households are involved in multi-residency or circular migratory movements at a regional, national, and international scale. Taking the case of two rural areas close to the city of La Paz, we analyzed migration patterns and drivers behind migrant household decisions in the Bolivian Andes… Our results underline that migration is a traditional peasant household strategy to increase income and manage livelihood risks under rising economic pressures, scarcity of land, insufficient local off-farm work opportunities, and low agricultural productivity… Our results suggest that environmental factors do not drive migration independently, but are rather combined with socio-economic factors.”
The rising danger of glacial lake flooding in a warmer climate has important implications for humans and animal populations in Peru’s Cordillera Blanca. A recent study in CATENA by Adam Emmer et al. examined a large swath of nearly 900 high altitude Peruvian lakes in the mountainous Cordillera Blanca region, studying their susceptibility to outburst floods in light of modern climate change.
An outburst flood occurs when the dam containing glacial meltwater, usually comprised of either glacial ice or a terminal moraine (glacial debris lying at the edge of the glacier), fails. Glaciologist Mauri Pelto commented in the American Geophysical newsletter that the moraine dams are “just comprised of gravel, sand and clay dumped by the glacier” and “high water levels caused by upstream floods, avalanches or landslides can cause failure,” leading to major damage of the landscape. The team’s research elucidated that the incidence of glacial lake outburst flooding (GLOF) is increasing and the general distribution of alpine lakes is shifting upward in the region as temperatures warm.
Knowing a lake’s size, configuration and type allows local water management in the Cordillera Blanca to be improved, according to Emmer et al. By mapping lakes with the classification of either moraine-dammed or bedrock-dammed, the team’s analysis can help local hydrological experts improve water management techniques for the changing distribution of alpine water. It also contributes to the scientific community’s overall understanding of ongoing environmental change.
By studying the Cordillera Blanca region’s alpine lakes through a combination of remote sensing (high resolution aerial imagery and measurements) and field observations, Emmer’s team categorized 882 lakes by their size and altitude, ultimately referencing their findings with historical data to observe water redistribution over the last 60 years. Emmer et al. established that glacial lakes had expanded in size and number at higher elevations and disappeared at lower elevations since the 1951 study by Juan Concha in the same region. This finding confirms that environmental change and glacier retreat are strongly correlated in the high alpine.
Results from the analyses showed that from 1948 to 2013, lakes that remained in already deglaciated areas tended to be resilient and generally maintained water levels throughout the 65-year examination. Moraine-dammed lakes in particular resisted disappearing despite glacial retreat, suggesting that bodies of water dammed by materials other than ice were more adaptable to recently warmer temperatures.
The team also noticed that despite the recent resiliency of moraine dammed lakes, glacial lake outburst flooding was caused predominantly by these dams in the early portion of the Cordillera Blanca’s glacial retreat, in the 1940s and 1950s. Flooding in more recent years has occurred in bedrock-dammed lakes. Although glacial lakes were recorded to have shifted from 4250-4600m in the late 1940s to predominantly above 4600m today, no statistically significant trend was established relating outburst flooding to any particular elevation.
In order to reduce the risk of flood damage in local communities, Emmer et al. suggested continuous monitoring of young, developing proglacial lakes, using extensive flood modeling and outburst susceptibility assessments to account for future changes in the glacier. Understanding that the melting of glaciers is accelerating in a warming world, the need for more intensive local efforts in response to the threat of flooding is apparent.
The Peruvian government has responded to high lake levels in the mountains of the Cordillera Blanca by “building tunnels and concrete pipes through the [weakest] moraines to allow lake drainage to safe levels,” according to Pelto. The government then rebuilds the moraines over the drainage system to strengthen it. By incorporating the monitoring techniques suggested by Adam Emmer, the government has the opportunity to manage and stay ahead of the flood risk as temperatures continue to rise.
Glacial lake outburst flooding is hardly unique to the Peruvian landscape. This December, the Kathmandu Post illuminated the growing danger of GLOFs as the Nepalese Dhaulagiri Glacier recedes, creating a hazardous environment in the Mt. Nilgiri region. Researchers at the Chinese Institute of Mountain Hazards and Environment also established a strong link in Tibet between rising temperatures and glacial melting, contributing to more frequent and larger glacial lakes than in the past 50 years. With the growing number of alpine lakes and increased temperatures, ice dams are highly fragile and prone to failure.
Emmer et al.’s study offers an interesting evolutionary perspective on the state of the Cordillera Blanca. The study’s publication illustrates that even the planet’s most dramatic, seemingly unchangeable environments are plastic under the force of global climate change. The redistribution of alpine glacial lakes across the world’s mountainous regions indicates that the risk of outburst flooding should not be taken lightly. The team’s suggestions for future monitoring, to either mitigate the flooding hazard in populated regions or coordinate adaptation efforts, further illustrates the gravity of the situation. Although the risk of outburst flooding has only been studied in specific locations, the changing state of glacial lakes is already quantifiable and may be an effective proxy for monitoring the future extent of global warming.