BY ZACH COHEN
Zach Cohen is SAIS Perspectives’ Editor-in-Chief and a Second Year MAIR Student specializing in Development, Climate, and Sustainability
With natural resource demands on the rise and climate change exacerbating environmental challenges, the Water-Energy-Food (WEF) Nexus has emerged as an important framework for analyzing the interconnections between the water, energy, and food sectors. The nexus approach emphasizes that no resource exists in a vacuum, and that fostering resource security requires a holistic understanding about the ways in which these systems are interlinked. This approach is particularly valuable for analyzing glaciers, which serve as critical parts of the WEF nexus for many regions around the world. However, as global temperatures have steadily risen in recent decades driven by anthropogenic climate change, the pace of glacial retreat has hastened. Rapid glacial retreat has vast consequences for natural ecosystems and societies, including significant impacts to the WEF nexus driven by diminishing freshwater availability.
One region facing an acute risk from glacial retreat is the Andean Region of South America. The region is home to over 4,000 glaciers, spread along the entire extent of the Andes Mountains from the Tropical Andes in Peru and Bolivia to the Southern Andes of Argentina and Chile, and they serve as vital inputs into the region’s water, energy, and food systems.[i] Given the region’s reliance on glaciers, glacial retreat poses a particularly daunting challenge.
Glaciers and the Hydrological Cycle
Glaciers and ice caps hold 75% of the world’s freshwater resources and serve as a critical input to global water systems, with 1.9 billion people relying on glacial runoff as a source of drinking water.[ii] When a glacier is in equilibrium – meaning its accumulation and ablation are equal – it can provide a consistent and reliable source of water for downstream communities, as the runoff meltwater from the glacier flows into rivers and streams. Critically, this means that even during dry periods, mountain glaciers in semi-arid regions can serve as a “savings bank” or frozen reservoir that can mitigate the impact of low precipitation through the provision of a constant source of water.[iii]
However, the state of glaciers in the world has been radically altered by climate change. As a result of rising temperatures, glaciers have faced 35 consecutive years of loss in mass, and the speed of glacial melt has doubled in Antarctica and Greenland since just 2000.[iv] Moreover, given the high concentration of greenhouse gas emissions in the atmosphere, a significant amount of future glacial retreat is essentially locked in, and even climate change mitigation efforts we take today cannot prevent the acceleration of glacial retreat.[v]
The rapid retreat of glaciers driven by climate change poses broad global repercussions alongside specific local challenges. On a global level, glacial retreat is one of the biggest drivers of sea level rise. Between 1961 and 2016, glacial retreat led to an increase in sea levels by 27 millimeters, and the U.S. Geological Survey estimates that a total retreat of all glaciers would result in a staggering 70-meter rise in sea level.[vi] On a regional or local level, glacial wastage means less water availability; as mountain glaciers shrink in size there will be a decrease in meltwater flows downstream.
There are also differentiated impacts of glacial retreat depending on the time frame of analysis, due to the concept of ‘peak water,’ which refers to the maximum amount of meltwater supply coming from the glacier.[vii] For glaciers that have not reached peak water, the current period of accelerated retreat will increase the amount of meltwater sent downstream and provide temporary boons to the communities they serve. However, after peak water has been reached, the overall meltwater will begin to decline, as in the long run, the glaciers will get smaller and the amount of water able to flow will diminish.[viii]
Glaciers and the WEF Nexus in the Andes
There are several critical avenues through which glaciers interact with water, energy, and food systems in the Andean region. Glaciers are integral to the Andean water supply, especially given the region’s rapid urbanization. Large percentages of the countries’ urban populations are now living at high altitudes in water-stressed environments, particularly in Bolivia, Colombia, and Peru.[ix] As urban populations grow, so will water stress – but glaciers have served as a pivotal stopgap measure that has allowed these cities to survive and thrive. For example, La Paz, Bolivia relies on glaciers for as much as 85% of its water supply during the driest months of the year.[x]
Because glaciers provide consistent input into the Andean region’s water systems, they also help contribute to energy production. In 2018, the combined total installed hydroelectric capacity of Andean countries topped 56,000 MW, with hydropower making up a significant or majority share within the energy mix of most Andean countries. [xi] More than 70% of energy production in Colombia and Ecuador, and more than 80% in Peru, stems from hydropower.[xii] Critically, this massive amount of hydropower production is highly dependent on glacial runoff to sustain flows.
Finally, glacier runoff serves as an important input into agriculture systems in the region. Around 17% of cropland in the Andean region is in the mountains, directly downstream from glacial flows.[xiii] Moreover, in many Andean countries, farms rely heavily on glacial meltwater as a main source of irrigation. In Bolivia, more than 400,000 hectares of irrigated land have a 45-100% reliance on glacial melt for irrigation practices.[xiv] Given that the success of agricultural production is often dependent on reliable and predictable water inputs, glaciers have historically played an important role in providing that consistency.[xv]
Impacts of Glacial Retreat on the WEF Nexus
While glacial retreat will have differentiated impacts across the Andean region, there is no question that the region’s glaciers are retreating writ large. 98% of glaciers in the Andes have shrunk since 2000, and in the tropical Andes, glacial mass has declined by between 30% and 50% since just 1990.[xvi] Moreover, many Andean glaciers already reached their peak water runoff – as many as 95% in the low latitude Andes - and most of the rest are expected to reach peak water within the next 20 years, with vast anticipated reductions in glacial river flows.[xvii]
Given the importance of glacial runoff as a water input to the WEF nexus, the Andean region is facing increased water stress due to glacial retreat. One of the most alarming examples occurred in 2016 in Bolivia, as the country was hit by a historically devastating drought, and its glaciers had shrunk to such an extent that they were effectively unable to mitigate the impacts. This incurred severe water shortages; La Paz instituted water rationing, and some agricultural areas lost half their crop production.[xviii]
As glacial meltwater flows decrease, it also impacts the availability of water for energy production. A 2008 study estimated that for a major hydropower plant in Peru, a 50% reduction in glacial runoff would decrease the plant’s energy output by 20% annually.[xix] Because the bulk of energy production in Peru comes from hydropower, the compounding impacts of a 20% reduction in energy output across many plants would be massive. The unpredictability of water resources for energy has even led to financial ruin for some. Notably, the Alto Maipo hydroelectric plant in Chile began construction in 2008 with the expectations of reliable water flows, but in 2021 it produced less than half of its expected generation and forced the owners into bankruptcy.[xx] Given that hydropower plants can be extremely costly and have life cycles up to a century, countries may reconsider investing in additional hydropower capacity that will only be viable in a context of persistent glacial melt.[xxi]
Glacial retreat also brings risks of natural hazards which can have secondary repercussions on the WEF nexus. Most prominent is the risk of Glacial Lake Outburst Floods (GLOFs). Glacial lakes are formed as glacial meltwater begins to pool and is dammed by ice or moraines - but as glacial runoff accelerates and the glacial lake grows in size, it can break past its barriers and flood downstream.[xxii] The risks of potential GLOFs worldwide have accelerated alongside climate change, and the Andean region is at high risk of such events.[xxiii] GLOF’s have the capacity to severely damage everything in their path - communities, infrastructure, agriculture, energy systems, and more. In Chicón, Peru, the majority of arable agricultural land and population is located in a narrow valley that aligns directly with the path that future GLOFs would likely travel.[xxiv]
Declining glacial meltwater flow as a result of glacial retreat also has geopolitical repercussions for the region’s water stressed countries, highlighting the transboundary nature of the WEF nexus. One example of such competition is the conflict between Bolivia and Chile at the International Court of Justice (ICJ) over water rights to the Silala River, which originates in Bolivia and passes into Chile. Bolivia was seeking full usage rights over the river, while Chile hoped to mark the river as an international waterway to preserve its own access.[xxv] The importance of this case for both countries stems from their growing water stresses; as water resources are becoming further strained, both countries feel a necessity to secure whatever water rights they can, to guarantee they have alternative sources to tap once their glaciers are depleted. Notably, in December 2022 the ICJ rejected Bolivia’s claim to full sovereignty over the river, urging the two countries to cooperate over the “shared resource.”[xxvi] Nonetheless, it is unlikely that this will be the last source of conflict over water resources between Andean countries as glacial retreat advances in the coming years.
As noted earlier, glacial retreat can paradoxically provide short term benefits if the glacial runoff has yet to reach peak water. This is currently the case in Peru’s northern deserts, where glacial melt has been a boon to agricultural production. According to a New York Times profile of the region, the government has taken advantage of increasing flows by making large investments in industrial-scale agriculture and canals, altogether cultivating more than 100,000 acres of land in the desert since the 1980s.[xxvii] The region has subsequently seen significant economic growth, with the increased water availability transforming the lives of many smallholder farmers and increasing Peru’s agricultural export capacity. However, the level of growth that the region has experienced is highly unsustainable; as water resources diminish, the potential for a cascade effect across the water, food, and energy sectors is incredibly high, given how tightly linked the three have been to glacial meltwater in the process of economic development. Whether it was irresponsible to encourage development in such a context is a different question entirely – but it is clear that Peru will need to prepare for the eventuality of a crisis driven by glacial retreat in the region.
Potential Solutions
With so many interrelated impacts to the WEF nexus, glacial retreat represents one of the most alarming climate-driven challenges in the Andean region. But the situation is far from hopeless, as policymakers and organizations in the region can proactively respond and plan for a glacierless future through innovative policies and strategies.
At the heart of the challenge of glacial retreat is diminishing water supply and water storage. To ensure that lower glacial flows do not seriously impede daily life, energy production, food production, and the economy overall, countries must improve the efficiency of their current water usage or identify alternative sustainable sources of water to fill the growing gap left by shrinking glacial flows. These efforts manifest in a number of different ways. In La Paz, the municipal government is working with international donors to fix leaky water infrastructure to improve efficiency and prevent water losses.[xxviii] In Ecuador, there are efforts underway to maximize water storage capacity of the country’s wetlands. And in Chile, conservationists are utilizing an innovative approach of creating artificial glaciers, constructing enormous ‘Ice-Stupas’ in the mountains which capture and freeze winter rain for future use.[xxix] To complement these strategies, countries should also consider improving their water harvesting capacities. Scholars behind the “Andean Glacier and Water Atlas” suggest the use of rustic micro dams, which serve as small reservoirs that both ensure consistency of water supply on a community level as well as promote groundwater recharge.[xxx]
Another critical component of the response to glacial retreat is community adaptation and disaster risk reduction, ensuring that at-risk communities have the tools and information to prevent, prepare for, and respond to potential glacier related disasters. For example, the World Bank has supported adaptation strategies in the Andes through modeling the likely paths of glacial retreat, to aid communities in understanding the pattern of retreat and likely risks.[xxxi] Another example of effective risk reduction work is the Glaciares+ program, an initiative from CARE and the University of Zurich in conjunction with local communities in Peru.[xxxii] The project centered on mitigating the risks of glacial retreat, strengthening the resilience of communities to respond to potential shocks, and developing early warning systems and evacuation maps, and the project overall supported 70,000 people through these risk reduction measures.
While the above strategies deal explicitly with the linkages between glaciers and the WEF, some countries have also approached glacial retreat through legal protection mechanisms to more broadly ensure that glaciers are better preserved. Over the last decade, Glacier Protection Laws (GPLs) have become prominent topics of policy debate in the Andean region.[xxxiii] They have primarily been designed in reference to glacial mining, as countries such as Argentina and Chile have economies that are “sustained by mining in glacierized ranges” leading to compounding environmental challenges on top of climate-driven glacial retreat.[xxxiv] Argentina passed a GPL in 2014, that protects its glacierized environments from resource extraction and mining, to ensure that glacial meltwater remains uncontaminated and that its resources are better preserved. However, some scholars have criticized Argentina’s GPL as counterproductive for the purposes of climate adaptation – for example, it hinders the capacity of scientists to make necessary adaptive interventions, and effectively prohibits communities to tap into the resources of glacial lakes. Future GPLs will need to take into account the intersection of glaciers with climate change and the WEF nexus as they work to protect glacierized environments.
Finally, given the transboundary nature of climate change and the WEF, it is pivotal that Andean countries find avenues of cooperation to deal with glacial retreat. Countries should avoid attempts to hoard the region’s natural resources, as observed in the Bolivia-Chile ICJ case. Rather, as climate researcher Kate Cullen argues, Andean countries have a “unique opportunity to collaborate on transboundary initiatives,” with potential multilateral outlets taking the form of knowledge and resource sharing, cooperative glacial monitoring, and joint water resource management.[xxxv] Already, there are a number of regional environmental initiatives – such as the Andean Community and the Consortium for the Sustainable Development of the Andean Ecoregion – which could serve as suitable paths for engaging on the intersection of glaciers and the WEF nexus.[xxxvi]
Ultimately, while evaluating the compounding threats of climate change and glacial retreat paints a daunting picture, it also illuminates the value of a WEF nexus approach to understanding how climate change will reshape communities. This approach highlights the central role that water, and specifically glacial meltwater, occupies within the Andean WEF nexus – from drinking water to irrigation to powering massive generators. As glaciers waste away, and their water which once powered whole societies vanishes, there is little doubt that the nature of life in the Andean region will be significantly changed.
[i] US EPA, OAR, “Climate Change Indicators: Glaciers,” Reports and Assessments, July 1, 2016.
[ii] Davies, Bethan. “The World’s Mountain ‘Water Towers’ Are Melting, Putting 1.9 Billion People at Risk.” The Conversation. December 17, 2019.
[iii] Kate Cullen, “4 Andean Cities Adapting to Glacier Retreat to Preserve Water Security,” The City Fix, The World Resources Institute, June 27, 2018.
[iv] “Global Glacier State,” World Glacier Monitoring Service, accessed December 12, 2022.
[v] Kari Synnove Johnansen et al., “The Andean Glacier and Water Atlas: The Impact of Glacier Retreat on Water Resources,” UNESCO, 2018, 9.
[vi] “Contribution to Sea-level Rise,” World Glacier Monitoring Service, accessed December 12, 2022.; “How would sea level change if all glaciers melted?” U.S. Geological Survey accessed December 10, 2022.
[vii] Johnansen et al., “The Andean Glacier and Water Atlas,” 43.
[viii] Valentina Radić and Regine Hock, “Glaciers in the Earth’s Hydrological Cycle: Assessments of Glacier Mass and Runoff Changes on Global and Regional Scales,” Surveys in Geophysics 35, no. 3 (May 1, 2014): 813–37.
[ix] Johnansen et al., “The Andean Glacier and Water Atlas,” 27.
[x] Monica Machicao, “Bolivia’s Tuni glacier is disappearing, and so is the water it supplies,” Reuters, January 4, 2021; Cullen, “4 Andean Cities Adapting to Glacier Retreat to Preserve Water Security.”
[xi] Johnansen et al., “The Andean Glacier and Water Atlas,” 29.
[xii] “Hydropower,” North Cascade Glacier Climate Project. Last updated 2018.
[xiii] Johnansen et al., “The Andean Glacier and Water Atlas,” 30.
[xiv] Ibid.
[xv] Fraser, Barbara. “Climate Change Equals Culture Change in the Andes.” Scientific American. October 5, 2009.
[xvi] “Dramatic retreat of the Andean glaciers over the last 30 years.” Science Daily. April 8, 2013.
[xvii] Graham McDowell, Michele Koppes, Leila Harris, Kai M. A. Chan, Martin F. Price, Dhawa G. Lama, and Gladys Jiménez, “Lived Experiences of ‘Peak Water’ in the High Mountains of Nepal and Peru,” Climate and Development 14, no. 3 (March 16, 2022): 268–81.
[xviii]“Shrinking glaciers cause state-of-emergency drought in Bolivia,” The Guardian, November 28, 2016.; Linda Farthing, “‘We Are in Shock’: Historic Bolivia Drought Hammers Homes and Crops,” The Guardian, November 25, 2016.
[xix] “Hydropower,” North Cascade Glacier Climate Project.
[xx] Jenna Travers, “Glacier Retreat in the Andes Is Bankrupting a Billion Dollar Corporation,” Columbia Climate School, April 15, 2022.
[xxi] “Climate Impacts on Latin American Hydropower,” International Energy Agency, January 2021.
[xxii] Neelima Vallangi, “Glacial Lakes Threaten Millions with Flooding as Planet Heats Up,” The Guardian, May 2, 2021.
[xxiii] Alina Motschmann, Christian Huggel, Randy Muñoz, and Angela Thür, “Towards Integrated Assessments of Water Risks in Deglaciating Mountain Areas: Water Scarcity and GLOF Risk in the Peruvian Andes,” Geoenvironmental Disasters 7, no. 1 (September 23, 2020): 26.
[xxiv] Motschmann et al., “Towards Integrated Assessments of Water Risks in Deglaciating Mountain Areas.”
[xxv] Heloise Garry, “The Case of the Silala River: Between the Laws of Men and the Laws of Nature,” Earth.Org, September 10, 2019.
[xxvi] International Court of Justice, “Dispute over the Status and Use of the Waters of the Silila – Judgement revised by President,” December 1, 2022.
[xxvii] Casey, Nicholas Casey, “In Peru’s Deserts, Melting Glaciers Are a Godsend (Until They’re Gone).” The New York Times. November 26, 2017.
[xxviii] Cullen, “4 Andean Cities Adapting to Glacier Retreat to Preserve Water Security.”
[xxix] “Conservationists in Chile Aim to Freeze Water in Man-Made Glaciers.” Reuters. October 28, 2021.
[xxx] Johnansen et al., “The Andean Glacier and Water Atlas,” 63.
[xxxi] “Fighting the Impacts of Glacier Retreat in the Tropical Andes.,” The World Bank, September 21, 2016.
[xxxii] “Glaciares+,” Care International, accessed November 28, 2022.
[xxxiii] Pablo Iribarren Anacona et al. “Glacier Protection Laws: Potential Conflicts in Managing Glacial Hazards and Adapting to Climate Change,” Amibo 47 (2018).
[xxxiv] Ibid.
[xxxv] Kate Cullen, “As Andean Glaciers Retreat, So Does Regional Security,” New Security Beat, September 11, 2018.
[xxxvi] Johnansen et al., “The Andean Glacier and Water Atlas,” 68.
Photo credits: Juliette Denis-Senez Jappe from SAIS Perspectives 2022 Photo Contest