“The extent of pre-Columbian land use and its legacy on modern ecosystems, plant associations, and species distributions of the Americas is still hotly debated. To address this gap, we present a Holocene palynological record (pollen, spores, microscopic charcoal, SCP analyses) from Illimani glacier with exceptional temporal resolution and chronological control close to the center of Inca activities around Lake Titicaca in Bolivia. Our results suggest that Holocene fire activity was largely climate-driven and pre-Columbian agropastoral and agroforestry practices had moderate (large-scale) impacts on plant communities. Unprecedented human-shaped vegetation emerged after AD 1740 following the establishment of novel colonial land use practices and was reinforced in the modern era after AD 1950 with intensified coal consumption and industrial plantations of Pinus and Eucalyptus. Although agroforestry practices date back to the Incas, the recent vast afforestation with exotic monocultures together with rapid climate warming and associated fire regime changes may provoke unprecedented and possibly irreversible ecological and environmental alterations.”
“Politicians have tussled for years over the fate of the Tongass, a massive stretch of southeastern Alaska replete with old-growth spruce, hemlock and cedar, rivers running with salmon, and dramatic fjords. President Bill Clinton put more than half of it off limits to logging just days before leaving office in 2001, when he barred the construction of roads in 58.5 million acres of undeveloped national forest across the country. President George W. Bush sought to reverse that policy, holding a handful of timber sales in the Tongass before a federal judge reinstated the Clinton rule.
“The Programme for Monitoring of the Greenland Ice Sheet (PROMICE) has measured ice-sheet elevation and thickness via repeat airborne surveys circumscribing the ice sheet at an average elevation of 1708 ± 5 m (Sørensen et al. 2018). We refer to this 5415 km survey as the ‘PROMICE perimeter’ (Fig. 1). Here, we assess ice-sheet mass balance following the input-output approach of Andersen et al. (2015). We estimate ice-sheet output, or the ice discharge across the ice-sheet grounding line, by applying downstream corrections to the ice flux across the PROMICE perimeter.”
Photographer James Whitlow Delano has created a series of powerful images of Bolivia’s ongoing water crisis. His photos focus on the Altiplano, the high plateau where the Andes Mountains are at their widest and which crosses the borders of Bolivia, Peru, Chile, and Argentina. La Paz, Bolivia’s capital, is the largest city on the plateau. Families from rural areas are moving into La Paz and its largest satellite city, El Alto, because the agricultural way of life they rely on is no longer viable due to a lack of water. These families move into slums in the cities, like the one captured below, hoping to find better paying jobs.
Rural areas are struggling because the glaciers they rely upon are melting, which means less water for farming or snow for skiing. The lodge shown below was formerly a part of the highest ski resort in the world, but now sits empty because the Chacaltaya Glacier, which filled the adjacent valley, melted entirely in 2009 due to warmer and more frequent El Nino events.
Mountains in the Andes, like Condoriri, currently show what the region would look like without the effects of climate change. Glaciologist Edison Ramirez conducted a study that predicted, however, that the glaciers on the mountain may completely melt over the course of the next thirty years.
The melting of the glaciers has already had negative effects; along the shores of the dried up Lake Poopo sit quinoa plants in desiccated soil. Migration from rural areas to Bolivia’s cities is driven by drought. The difficulties created by drought are contributing to residents’ moves into bigger cities.
Other lakes and ponds in the Altiplano are at risk of suffering the same fate; below is a pond in the process of drying up. The melting of the glaciers and the lakes they feed is significant because the Altiplano does not get enough rain to support those who live there—It relies on glacial melt to support the human population.
Since the series on Bolivia was posted in late June, @everydayclimatechange has highlighted water shortages in Chennai, India; wildfires in Yosemite; and youth climate strikes inspired by Greta Thunberg, a Swedish youth climate activist.
A study published in Nature Climate Change gives a thoughtful overview on the use of GRACE satellites in tracking small changes on the earth’s gravitational field, which is one of the major contributions in observing glacier retreat.
“Interactions between the different climate system components involve mass variations in continental surface and sub-surface water storage (rivers, lakes, ground water, snow cover, polar ice sheets and mountain glaciers), as well as the mass redistribution within and between ocean and atmosphere. These mass movements are inherent to the evolution of droughts, floods, large-scale ocean currents, ice-sheet and glacier changes, and sea-level rise. Launched in 2002, the Gravity Recovery and Climate Experiment (GRACE) satellite mission1 added a unique component to the existing suite of Earth observations: time-resolved gravity measurements of global-mass redistribution, a fundamental building block crucial to understanding the complex interactions and transitions involved in today’s changing climate.”
“Monitoring of ice volume changes across mountain ranges provides a very sensitive indicator for the early detection of climate-related changes associated with global warming… However, glacier monitoring data are strongly biased towards the Northern Hemisphere, with sparser information from the Southern Hemisphere. Thus observations from the mid-latitude mountains of New Zealand, which have over 3,000 glaciers, are of considerable value for the global climate monitoring network.”
A study published by Hydrological Processes examines high-elevation peatlands in Peru and Bolivia. These peatlands are often close to glaciers, and present many ecosystems services while also supporting indigenous pastoralist livelihoods.
“Little is known about the hydrological processes supporting peatlands in other regions of the Andes, particularly the more arid Puna region of the Andes that extends from central Peru to central Chile. The vulnerability of these peatlands and associated socioecological systems to glacier loss under climate change is largely contingent upon how exclusively wetlands are supported by glacier melt water rather than hillslope groundwater recharged by precipitation. Future climate change effects on precipitation in the Andes are complex to predict could influence not only stream flow but also recharge of groundwater flow systems that could support wetlands.”
Bridging Traditional Knowledge and Satellite Images in Bolivia
From Regional Environmental Change: “In the Andes, indigenous pastoral communities are confronting new challenges in managing mountain peatland pastures, locally called bofedales. Assessing land cover change using satellite images, vegetation survey, and local knowledge (i.e., traditional ecological knowledge) reveals the multi-faceted socio-ecological dimensions of bofedal change in Sajama National Park (PNS), Bolivia. Here, we present results from focus groups held in 2016 and 2017 to learn about the local knowledge of bofedales in five Aymara communities in PNS. Land cover maps, created from Landsat satellite imagery, provided a baseline reference of the decadal change of bofedales (1986, 1996, 2006, and 2016) and were field verified with vegetation sampling. At the park level, the land cover maps show a reduction of healthy bofedales (i.e., Juncaceae dominated peatland) cover from 33.8 km2 in 1986 to 21.7 km2 in 2016, and an increase in dry mixed grasses (e.g., Poaceae dominated land cover) from 5.1 km2 (1986) to 20.3 km2 (2016). Locals identify climate change, lack of irrigation, difficulty in water access, and loss of communal water management practices as key bofedal management challenges. Local improvement of bofedales was found in one community due to community-based irrigation efforts. Bridging knowledge of mountain land cover change helps to articulate the socio-ecological dimensions that influence local decision-making regarding bofedal management, and consideration of local actions that may be strengthened to support the sustainability of bofedales for local livelihoods in the context of climate change in the Andes.”
Pleistocene and Holocene Cirque Glaciation in the Western United States
From Nature: “Our [glacier chronology] demonstrates that each of the moraines originally interpreted as Neoglacial was deposited during the latest Pleistocene to earliest Holocene (between ~15 and 9 ka), indicating that, with the exception of some isolated locations, cirque glaciers in the western U.S. did not extend beyond their LIA limits during much, if not all, of the Holocene.”
This Photo Friday, journey to Sajama, Bolivia, through photos taken by Karina Yager, a professor at the School of Marine and Atmospheric Sciences at Stony Brook University, on her recent trip to the country.
Joining two Bolivian scientists, Rosa Isela Meneses and Humber Alberto, from the Bolivian National Herbarium and the Natural History Museum, the trio conducted a field survey at Sajama National Park, monitoring vegetation change in bofedales (high Andean peatlands). In Sajama, glacier retreat, climate change and local changes in land use and livelihoods are impacting the bofedales, which are key to sustaining pastoralism in the region. Indigenous Aymara herders, who have a centuries-long tradition of raising llamas and alpacas in the region, maintain and extend these peatlands through the careful construction of irrigation canals. In addition to supporting domesticated animals and local livelihoods, the bofedales also help regulate water resources for mountain biodiversity, including vicunas and many Andean birds.
Yager expresses her gratitude to NASA ROSES LCLUC for financial support for the project, to her Bolivian colleagues and local residents, and to Apu Tatay Sajama, who all contributed to the success of the trip.
In a bid to preserve ice cores and valuable climate information from some of the world’s most endangered glaciers, scientists are creating a global ice archive sanctuary in Antarctica. The Ice Memory project is being led by the Université Grenoble Alpes Foundation.
From Mont Blanc Massif’s Col du Dôme glacier to the Illimani glacier in Bolivia, over 400 ice cores have been retrieved to be preserved in the ice bunker.
To learn more about Ice Memory, see the video below from the Université Grenoble Alpes Foundation:
The current state of climate policy in Bolivia is one of caveats: activists have carved out a legal space for indigenous concepts such as “Mother Earth,” but state policies simultaneously encourage the expansion of agriculture further into the Amazon. In addition, CO2 emissions have reached an all-time peak, contributing to the melting of the Andean glaciers and emerging environmental crises in Bolivia like drought. In a recent article in the Journal of Political Ecology, Anders Burman theorizes a corrective to the contradictions that are inherent to the Bolivian’s conservation efforts. The divide, as he sees it, exists along the axis of differing ontological practices—what forms of existence are deemed rational and acceptable to indigenous and non-indigenous actors. By bringing the capitalist and the indigenous into sincere dialogue, he seeks to resolve these growing climate disturbances.
Indigenous voices are by no means quiet in Bolivian politics, and indeed indigenous cultures have even been celebrated by the government since a wave of neoliberal multiculturalism took root in Bolivia in the 1990s. But Burman argues that the Bolivian government, even in legally granting subjectivity to entities like mountains, glaciers, and rivers, failed to actively integrate the ontological legitimacy of those indigenous spirits. Indigenous Aymara practices have been treated as folklore—as imperfect embodiments of scientific truth. In other words, the Bolivian state pays lip service to notions of multiculturalism without actually accepting those other cultures as existentially valid.
The gap in ontological rendering also intervenes between non-state activists and indigenous leaders. Even where climate activists and indigenous organizations are in fundamental agreement, they express the problems of climate change in fundamentally different ways, preventing them from working together. For climate activists, climate change is coded into a terminology that emphasizes greenhouse gas emissions, CO2, and the Keeling curve, while indigenous Aymara people speak about climate in terms of achachilas, awichas, ajayu uywiris, and maranis. Indigenous delegates are invited to participate in climate meetings, but they are not called upon to speak; rather, they listen to urban activists recount the proceedings of the Kyoto Protocol.
The climate movement in Bolivia, while characterized on the surface by plurality and heterogeneity, is effectually a non-indigenous, middle class movement. The form of climate action in Bolivia that receives media attention and political space does not emerge from any progressive synthesis of differing ontological positions, but from a select group of well-positioned actors. This asymmetrical power dynamic, in which scientific knowledge is seen to constitutelegitimate knowledge, participates in the greater global system of power asymmetries, whereby capitalist, western-centric, colonial levers continue to extract value from the non-western world.
In climate negotiations within Bolivia, Burman sees the vestiges of European colonial expansion, which was characterized not only by the colonization of peoples, but of knowledge itself. With the expansion of the colonial sphere came the destruction of different ways of conceiving of the world and one’s place within it. Indigenous and local forms of knowledge were brutally repressed, and even after former colonies became liberated, the coloniality of knowledge lingered.
Part of Burman’s task is to integrate extant indigenous knowledge into the project of environmentalism. But what exactly do those forms of knowledge look like? In contrast to the prevailing Western notion of nature as an amoral, outside entity, in Andean conceptions of nature, mountains, rocks, glaciers and rivers are agents with intentionality, perceptive to human actions. Human beings and non-human entities are equally endowed with ajayu, the force of living agency and subjectivity. Powerful actors, like ancestors, are the same substance as the mountains, and they control the weather. If the human world does not adhere to a certain ceremonial and ethical standard, the natural world responds by punishing the local community.
So the indigenous concept of “pacha usu,” which can be translated as “climate illness,” while linguistically similar to the scientific notion of climate change, refers not merely to pollution and greenhouse gas emissions, but to the ethical degradation that attends to modern practices such as mechanized agriculture, industrially processed foods, ritual disappearance, and community alienation. To indigenous activists, the snow is melting on the mountains and glaciers because of an ethical failure on the part of one segment of humanity. For the Aymara people, the segment of the population responsible for climate change are called Q’ara. They exploit the land and the labor of others and do not participate in the moral economy of the indigenous community. The Jaqi, however, are those whose lives are characterized by reciprocity—with the land, the community, and the spirits. These are ethical labels related to specific livelihoods and social practices and are not limited to any individual ethnic category.
Burman sees the epistemological practices of the Aymara as an alternative approach to structuring relations between the self and the world, and as a challenge to the colonial, extractive apparatus that is destroying the planet. This effort, which he calls “ontological disobedience,” is a mode of securing the space necessary for alterities to transform the dominant capitalist framework. Under this framework, CO2 molecules coexist with maranis, and INDCs and achachilas cohabit the conversation about climate justice.
In an interview with GlacierHub, Burman described ontological disobedience as acts that do not comply with the reality that is mandated by the powerful. “It might be as simple as introducing other concepts and notions – and, in the end, other beings – than the ones sanctioned by modernity into the environmental justice debate. This may be the basis for a radical critique of capitalist extractivism – a critique from outside of the modernist ontological concepts that underpin the current world-system. Environmental conflicts are often also ontological conflicts, and as an anthropologist working with environmental issues, I see it as my responsibility to try to face up to that analytically,” he stated.
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.
Bolivia is currently in the midst of the worst drought in twenty-five years following decades of intense water crises, including an infamous “water war” in 2000 in the city of Cochabamba in which tens of thousands of Bolivians protested the privatization of water. To cope with the current situation, Bolivia’s president Evo Morales has declared a national state of emergency, imposed stricter water rationing, and even fired a top water official, but can more be done to alleviate the crisis?
In a recent report for the World Bank Group, Sarah Botton et al. cover the current crisis and explain how a blend of “big system” water infrastructure, in which a single operator manages the piped system, and “small system” infrastructure, in which individuals informally control water resources, can help conditions in La Paz, Bolivia’s capital, and El Alto, a large adjacent city known for its high elevation and largely indigenous population.
Botton et al. present a case study of water management in La Paz and El Alto to consider the benefit of future water management strategies in the region. The central and oldest neighborhoods of these Bolivian cities have traditionally had better access to water, with poorer communities suffering from noteworthy shortages or decreased access, according to Botton et al. As a result, both cities have gone through cycles of public and private management before changing back to a public management system in 2007.
Dirk Hoffmann, a professor at Karlsruhe University of Applied Sciences in Germany and an expert in glacier change and glacier lake outburst flood risk in the Bolivian Andes, explained in an interview with GlacierHub that the immense population growth in La Paz and El Alto further complicates water management issues in the area. He indicated that the urban area of the metropolis of La Paz and El Alto is growing 40,000 to 50,000 people each year.
“The water supply system in La Paz and El Alto has not kept up with the population growth,” Hoffmann told GlacierHub. To make matters worse, Hoffmann explained that there is a 40 to 50 percent loss of water as it travels from the source due to old water pipes, open canals, infiltrations, and (illegal) access by users.
In 1997, while under public management, 95 percent of the La Paz population was connected to the drinking water system and 80 percent to sewers, according to Botton et al. In El Alto, where the population is poorer and more heavily indigenous, only 65 percent of the population was connected to drinking water and 25 percent to sewers. In order to provide more dependable water to the indigenous people, the decision was made by the government of El Alto in July 1997 to move the governance of the water system to a private company. La Paz similarly made the decision to privatize.
A contract was signed by both cities with Aguas del Illimani, a subsidiary of the French company Suez. However, problems with privatization arose because the company lacked the resources to equip the poorest households with water. Aguas del Illimani was ultimately replaced in 2007by Empresa Pública Social de Agua y Saneamiento (EPSAS), a public utility.
EPSAS dealt with a major setback in 2008 in which a landslide caused by heavy rain destroyed the pipes in the Pampahasi system, which supplied water to the southern and eastern part of La Paz. The area went without water for three weeks because repairs were delayed and EPSAS could not afford the US$450,000 s to repair the damage. They required a loan from the municipality and the national government.
President Morales and water experts maintain that climate change has contributed to and continues to exasperate the current water crisis in Bolivia. Bolivian glaciers have shrunk by 43 percent between 1986 and 2014, according to a study recently published by the Geosciences Union journal. Meanwhile, glacier meltwater in the region remains a crucial source of drinking water, irrigation, and hydropower, with two million residents in La Paz and El Alto reportedly receiving about 15 percent of their water supply from glaciers.
As water resources diminish in Bolivia, conflicts over their allocation will only intensify, Botton et al. explain. Hoffman emphasized to GlacierHub that, ironically, Bolivia is a big contributor to climate change due to deforestation in its lowlands, when counted on a per capita base. Deforestation brings smoke particles to the glaciers, accelerating their melting (although the exact magnitude still has not been established). In this sense, Bolivia continues to contribute to climate change, which has negatively impacted it own water supply.
Botton et al. analyze the differences between “big systems,” like the ones used in La Paz and El Alto, which are maintained by a single operator that manages the pipes of the entire municipal water system, and “small systems,” which offer an alternative management option.
In small systems, inhabitants of a rural area informally control the system and turn the resource into a service for the community. The operators are required to register with the Ministry of Water, but many currently do not because of onerous procedures involved.
In La Paz, small systems are located on the western slopes, which are considered “non-constructible” for big systems. These small systems provide water without undermining the big system, which lacks options for expanding. Another positive of small systems is that they rarely need repairs, and when they do, those repairs are done more easily with a technically simple approach. Botton et al. concur that future solutions for La Paz and El Alto water issues will require coordination between big and small systems.
Hoffmann agrees that there needs to be more coordination among all of those involved and that there remains significant disagreement on who should have access to water or how it should be utilized. Many of the reservoirs used in La Paz and El Alto are on rural lands belonging to indigenous people, for example, who want to use the water for irrigation purposes. The indigenous people claim these natural resources are theirs. However, Bolivians living in the city want to use the water for drinking.
Hoffmann concluded, “The many actors involved are slowly becoming more convinced that they need an agreement between urban and rural populations.”
The mysterious Moche civilization originated on the northern coast of Peru in 200-800 AD. It was known for its metal work, considered by some to be the most accomplished of any Andean civilization. But were the Moche the first Andean culture to originate copper smelting in South America?
While the Moche left comprehensive archaeological evidence of an early sophisticated use of copper, the onset of copper metallurgy is still debated. Some peat-bog records (records of spongy decomposing vegetation) from southern South America demonstrate that copper smelting occurred earlier, around 2000 BC.
The question motivated Anja Eichler et al. to launch a massive study of copper emission history. The details of the findings were subsequently published in a paper in Nature. Eichler, an analytical chemistry scientist at the Paul Scherrer Institute in Switzerland, and her team presented a 6500-year copper emission history for the Andean Altiplano based on glacier ice-core records. This is a new methodology applied to trace copper smelting.
“Copper is often referred to as the ‘backbone of Andean metallurgy – the mother of all Andean metals,’” Eichler explained to GlacierHub. “However, in contrast to the early copper metallurgy in the Middle East and Europe, very little information existed about its onset in the Andes.”
The ice-core they used for their research was drilled at the Illimani Glacier in Bolivia in 1999, nearby sites of the ancient cultures. It provides the first complete history of large-scale copper smelting activities in South America and revealed extensive copper metallurgy. Illimani is the highest mountain in the Cordillera Oriental and the second highest peak in Bolivia.
When asked about how she started her research, Eichler told GlacierHub, “I got involved in the project in 2012. At that time, PhD students and a post-doc had already obtained exciting findings and secrets revealed by ice-core records. We started looking at copper and lead as traces from copper and silver mining and smelting in the Andes.”
The results of Eichler et al.’s study suggest that the earliest anthropogenic copper pollution occurred between 700–50 BC, during the central Andean Chiripa and Chavin cultures, around 2700 years ago, meaning that copper was produced extensively much earlier than people originally thought.
“For the first time, our study provides substantial evidence for extensive copper metallurgy already during these early cultures,” said Eichler.
One of the most challenging parts of the research is that copper can show up in the ice core from natural as well as human sources. Eichler’s team accounted for this by calculating the copper Enrichment Factor, which is applied widely to distinguish the natural and anthropogenic origin of metal. The principle of this methodology is to measure the occurrence of different metals. If copper appeared naturally due to wind erosion, it would be found in association with other metals that co-occur with it naturally.
However, according to Eichler’s findings, there was only copper in central Andean Chiripa and Chavin cultures, without cerium or the other metals that occur with it in natural deposits. Hence, it was anthropogenic. The Chiripa culture existed from 1400 BC to 850 BC along the southern shore of Lake Titicaca in Bolivia, near Illimani Glacier. Soon after the Chiripa, came the Chavin culture, a prehistoric civilization that developed in the northern Andean highlands of Peru from 900 BC to 200 BC, named for Chavín de Huantar, the principal archaeological site where their artifacts have been found.
Copper objects from these earlier cultures are scanty. The reason why there is no sufficient archaeological evidence of copper usage, according to Eichler, is that very often artifacts were reused by subsequent cultures.
“It is known that metallic objects cast by civilizations were typically scavenged from artifacts of their predecessors,” Eichler explained. “Furthermore, ancient metallurgical sites are difficult to find because of the lack of substantive remains, particularly smelting installations. Prehistoric smelting furnaces tended to be small or smelting was performed on open fires and thus left little permanent remains.”
The two major sources of copper in the atmosphere— and hence in ice cores from glaciers, where the atmosphere deposits copper compounds— are smelting activities and natural mineral dust. The contribution of Eichler and her team has been to distinguish these and document the creativity of early cultures who developed means to smelt copper.
In South America, the tropical glaciers of the Andes have been shrinking at an alarming rate, leaving the local communities at risk of losing an important water source. In Bolivia, for example, an Andean glacier known as the Chacaltaya Glacier disappeared completely in 2009, cutting off a valuable water resource to the nearby city of La Paz during the dry season.
In total, the Andes Mountains are home to nearly 99 percent of the world’s tropical glaciers, with 71 percent located in Peru’s Cordillera Blanca and 20 percent in Bolivia, according to UNEP. Other tropical glaciers are found in the equatorial mountain ranges of Venezuela, Colombia and Ecuador. Over the past 30 years, scientists estimate that the glaciers of the tropical Andes have shrunk by 30 to 50 percent. This rate of decline predicts that within 10 to 15 years many of the smaller tropical glaciers will have completely disappeared.
Take a look at GlacierHub’s collection of images of the rapidly retreating Andean glaciers.
In December 2015, while the world’s eyes were on the UN Climate Conference in Paris, Bolivia’s Lake Poopó—once the country’s second-largest lake, with an area of 2700 square kilometers–dried up completely. This event was first recognized by the regional government, located in Oruro, and soon drew national and international concern. This attention has opened a discussion on the causes of this event and on the troubling possibility that the lake may never return to its earlier size.
Some people, like Bolivian President Evo Morales, were quick to attribute the drying of Lake Poopó to natural cycles, pointing out that the lake had previously dried out, but always recovered. But others claim that climate change has played a role that will continue into the future, and also note the negative impact of human activities–irrigation schemes and mining activities–which are very unlikely to end.
Based on available documentation and a field visit earlier this month, we are now in a position to share some preliminary conclusions on what happened to Lake Poopó, as well as to the perspectives for its recovery.
The current sharp decline is due most immediately to the strong El Niño event of 2015-16, which has greatly reduced rainfall in the November-March wet season, now reaching its final weeks. But the problem is rooted in long-term processes, which will not be reversed when the current El Niño event ends, most likely later this year.
The Physical Environment of Lake Poopó
Lake Poopó, like all other lakes, can be characterized by what limnologists–fresh-water ecologists–call a “water balance,” the relation between the water that enters the lake, and the water that leaves it. If unimpeded, a negative water balance will lead to the drying up of a lake. The water balance of Lake Poopó is influenced by its location in a semi-arid area (the average annual precipitation is about 370 mm) and its shallowness (the greatest depth is only 2.4 m).
Historically, Lake Poopó receives around two thirds of its water from a sole source, the Río Desaguadero; the remaining third comes from smaller rivers that flow directly into the lake and from rainfall onto the lake’s surface. The Río Desaguadero originates in Lake Titicaca, a large lake that straddles the border between Bolivia and Peru. As this river flows towards Poopó, it receives water from other tributaries, particularly the Río Mauri, an international river whose sources lie in Peru and Chile. Lake Titicaca and the other tributaries of Río Desaguadero receive water from rainfall, snowmelt and runoff from the glaciers on the cordilleras that ring the entire Titicaca-Poopó basin.
These sources provide Lake Poopó with water inputs that fluctuate from year to year, reflecting variations in the precipitation that the region receives. A set of locks that were constructed on Lake Titicaca in 2001 could permit the Binational Commission charged with managing the lake to release more water to the Río Desaguadero in dry years, but this possibility has never been realized and, given the water scarcity on the Peruvian side of the Titicaca basin, it seems very unlikely.
Local residents report a decrease in rainfall over the last 10-15 years, a pattern that is confirmed by data from weather stations for the last few decades and by tree-ring records that track rainfall over several centuries. Moreover, glacier retreat has diminished the contribution of meltwater to the lake–a valuable component of the water budget, since it historically compensated in part for the scanty rainfall in dry years. Bolivia has lost about half of its glacier area in the last 40 years, with particularly rapid retreat in the eastern portions of the Titicaca-Poopó basin, where the largest glaciers are located.
Moreover, climate change affects another component of the lake’s water budget: its losses. Higher temperatures lead directly to higher evaporation rates, a significant effect in this extremely shallow body of water.
Human Activities Impact Lake Poopó
In addition to these physical factors, human activities have reduced the water input into the lake. These activities begin far away, since new irrigation facilities draw from rivers on the Peruvian side of the basin, diverting water away from it.
In the last 10 years, new irrigation systems for small farmers have been built closer to the lake as well. During our trip around and onto Lake Poopó, we saw a large number of canals, many of them of makeshift construction, which divert water from the Río Desaguadero for agricultural purposes. According to Eduardo Ortíz, the Oruro regional government’s director for watershed management, there are around 250 irrigation schemes legally established on the Río Desaguadero. Other experts estimate that the total number of irrigation projects is closer to 1,000, suggesting that many of them lack legal authorization. Further down its course, the Río Desaguadero was entirely dry. When we came to the former shores of the lake, we found many small villages half-abandoned, especially on the western side of the lake. The final concern is the deterioration of water quality in the lake because of contamination from nearby mines at Huanuni and other site. Salts containing lead, cadmium, arsenic and other heavy metals leach into the lake. Local communities have protested this pollution in recent years. These toxic substances become concentrated in periods of low lake levels, and could affect the restoration of lake ecosystems even in years of heavier rainfall.
The drying of the lake has led hundreds of fishermen to lose their source of income, accelerating migration by the local population to urban areas. Antenor Rojas Flores, a local fisherman from the village of Untavi in his late 50s, has begun to work as a laborer in construction in the nearby city of Oruro to support his family. He says that he hopes that water and fish will return, so that he can go back to his life as it was before, but “only God knows” whether that will happen.
The decline of fishing has also impacted the commercial activities of women, many of whom have participated in local and regional markets. These people are members of the indigenous Uru Murato, an ethnic group with ancient roots in the region. Their livelihoods have always centered on the water, and the drying of the lake is threatening their continuity as a community; the barter relations with neighboring agricultural and pastoral communities, which supported them during dry spells in earlier historical periods, have weakened as these communities also face climate change and other pressures.
Worrying Perspectives for Lake Poopó
This set of circumstances leads to a bleak outlook for the lake. Its full recovery seems rather unlikely. The strong El Niño event of 1991-92, followed by a weaker event in 1994-95, led the lake to dry up as well; in the decades since then, it recovered neither its full size nor its full potential in terms of productivity and biodiversity. Historic lake sizes ranged between 2,500 and 2,700 square kilometers; for the current century it has been closer to 1,500 square kilometers, reflecting the impacts of climate change on evaporation and on glacier retreat. The irrigation facilities are likely to continue to divert water. It would take strong political will to reallocate water extensively throughout the international Titicaca-Poopó basin to bring the lake back to even a semblance of its state in the last century.