Melting Glaciers: Causes, Effects and Possible Solutions

Filippo Verre - June19, 2023

* L’immagine di copertina di questo report è stata presa dal sito Volver Viaggi, consultabile al seguente link: https://www.volverviaggi.it/navigando-tra-i-ghiacciai-della-patagonia-argentina/

Glaciers are a key component in the water supply for many human communities. According to various statistics, the so-called "water towers" support between 1.6 and 1.9 billion people who live in mountain areas or downstream from them. The water in solid form represented by ice, once melted at the beginning of the warm seasons, plays a key role in making the precious liquid flow into rivers, streams and lakes from which many human beings - and not only - get their supplies. Climate change, a phenomenon that is increasingly growing at various latitudes of the planet, is seriously endangering the structural stability of many ecosystems that rely precisely on the water supply guaranteed by glaciers. The rise in temperatures, favored by a massive production of carbon dioxide, makes the conservation of water in solid form increasingly precarious. In this regard, recent studies conducted using satellite recordings show high rates of loss of glacial mass that have occurred over the last few decades [1]. This is a widespread phenomenon, the effects of which are negatively impacting parts of Canada and Arctic Russia, Asia, Europe, North and South America.

Although the issue of the so-called melting glaciers – literally “the melting glaciers” – represents a global crisis in all respects, there are strong variations from region to region that reflect local atmospheric and topographic conditions. Consequently, some areas of the world are more exposed than others to the progressive erosion of the ice, often defined as “white gold” which, once melted, turns into “blue gold” for hundreds of millions of people who are heavily dependent on the mountain water supply cycle. In this regard, just think of the case represented by the Indus River, and its enormous drainage basin. This vast area, corresponding to approximately 1,165,000 km², is home to 120 million people who depend for over 40% on the water that melts every spring from the Himalayan glaciers. Potentially, even a minimal alteration in the quantity of water deriving from melted ice is capable of causing incalculable damage to millions of individuals living in this Asian quadrant. Asia is one of the continents most affected by the negative effects of melting glaciers. In many areas, in fact, both the functions of the ecosystem and the sustenance of local populations depend on a constant supply of melted water and the contribution of sediments and nutrients associated with it. In other words, the water supply deriving from melting ice can be considered a vital source, at the basis of the security of resources, well-being and environmental functions of many ecosystems.

In this report, after highlighting the main critical issues represented by the inexorable erosion of the "water towers", we will try to shed light on the possible solutions to try to stem this increasingly worrying phenomenon. Six measures will be presented – three short-term and three medium-long-term – that, if effectively implemented, could reduce the negative impacts that melting glaciers have on ecosystems and human communities. The environmental and socioeconomic stability of billions of people depends on the protection of glaciers, invaluable sources of water supply. The identification of potential strategies capable of preserving these fundamental mountain ecosystems as much as possible is an absolute priority for governments and international organizations.

Fig. 1: Una “torre d’acqua” e un lago montano
https://www.zai.net/articoli/ambiente/19230064/Scioglimento-dei-ghiacciai-accelerato-del-65–negli-ultimi-23-anni

Melting Glaciers. Causes and Effects

FUntil a few years ago, mountains were not seen as key elements of the Earth system. Tropical forests and oceans, for example, have historically enjoyed a substantial predominance in the “ranking” of ecosystems to be preserved. To justify this alleged superiority, it was argued that forests were to be preserved by virtue of their key role in trapping carbon dioxide and making the air more breathable. Similarly, the health of the oceans was and still is constantly monitored to preserve marine biodiversity as much as possible and keep pollution caused by plastic under control, which presents the most worrying cases of accumulation in the sea. Of course, the threats to forest and marine ecosystems are a very serious issue that has attracted the attention of scholars and experts for decades. The preservation of forests and oceans is a challenge that all human beings should take to heart with the utmost urgency. At the same time, however, it is appropriate to put the protection of mountain ecosystems on the same level of importance, especially understood as fundamental water reserves. The "water towers" store billions of m3 of resources every winter which, especially in the dynamic demographic context in which we are living, take on an increasing importance directly proportional to the increase in population.

What is the main cause of the progressive melting of glaciers? Without a doubt, global warming is a determining factor in the erosion of glaciers. Climate change significantly influences the amount of water stored in high mountain glaciers and the paths that water follows as it flows downstream. According to numerous studies, high mountains are warming faster than the planet average; temperatures on the peaks of the Himalayas, for example, have increased by almost 3.6 degrees Fahrenheit (2 degrees Celsius) since the beginning of the century, compared to a planetary average of "only" approximately 1.8 degrees Fahrenheit (1 degree Celsius). This change in mountain temperatures involves an alteration of the normal water cycle that in the past was much more static than it is today. Until recently, after months of accumulation in the usual format, with the arrival of milder temperatures the water would melt and flow downstream, replenishing myriads of more or less large watercourses. Now, however, the winter accumulation phase is increasingly thinning out, leaving little margin for mountain communities and increasingly reducing the large role that the "water towers" play as water reserves downstream. This has significant impacts on the entire mountain ecosystem. In fact, while humans may be relatively able to adapt to the rate of change downstream associated with the melting of glaciers, in many situations it is unlikely that the response of ecosystems will be adequate. As a result, a serious alteration of the quality of life for many animals is not unlikely, as well as a shift in the populations of terrestrial and aquatic fauna, in particular species adapted to glacial conditions. In this regard, let us refer to the numerous species of fish that live in mountain rivers accustomed to a rigid water temperature. As a result of the increase in heat in the water, it is not excluded that many of these fish may not adapt to the changed environmental conditions congenial to their existence [2].

Although man is more structured and ready to react to drastic changes in ecosystems than other animals, one cannot help but notice the great inconvenience that glacier erosion is already causing to millions of people. The variation in the quantity of water downstream following the unnatural melting of glaciers causes damage in various respects, ranging from the decreased quality of the available water, to energy uncertainty regarding the production of hydroelectric energy, up to the uncertainty of the quantity to be allocated to irrigation purposes.

I. Loss of water quality due to progressive erosion of glaciers

The retreat and melting of glaciers favors the chemical and physical erosion of local rocks, causing unnatural oxidation and, in some cases, acid drainage of rocks, which can have an impact on the acidity and toxicity of water. This phenomenon is already underway in some areas, such as the Cordillera Blanca in Peru, where some researchers have detected worrying cases of acidity and oxidation in so-called “melting” waters[3]. Furthermore, changes in glacial water production also have an impact on the temperature of the water itself. This is a key indicator of the quality of the resource, which can translate into a consequent increase in the vulnerability of alpine river ecosystems for which even small variations in water temperature can represent a significant stress factor.

The alteration of the water quantity as a consequence of the anomalous melting of glaciers can lead to a similar loss of quality of the nutrient sediments that many aquatic species use. In fact, to the already mentioned criticality associated with the change in temperatures for many fish species, a different and unpredictable nutritional supply is added following the erosion of glaciers. Sediments, which play a central role in governing the quality and availability of water, can easily turn into a contaminant, increasing turbidity and clogging of fish reproduction habitats. In fact, while providing an important ecosystem service for aquatic species and for the cycle present in nutrients, sediments can also transport and accumulate harmful elements capable of permanently damaging the life and the fluvial ecosystem of glacial watercourses[4].

A reduced quality of water directed towards the valley obviously also has negative effects for human beings. The increase in temperature that occurs with the melting of glaciers causes a bacterial proliferation that is difficult to counteract. The freezing waters almost completely limit the contamination by pathogens that inevitably infest every water basin. The introduction of large quantities of water at non-cold temperatures can lead to significant alterations in terms of drinking water. However, while humans can count on some weapons with which to deal with this eventuality - the use of water purification plants or boiling techniques - animal species are completely at the mercy of infesting agents.

II. Alterations in the quality and quantity of hydroelectric energy produced

A second important critical aspect of the melting of glaciers concerns the uncertainty in the production of hydroelectric energy. The latter is produced mostly in mountain areas thanks to the presence of waterfalls and differences in level that, by virtue of the kinetic force of the falling water, allow for constant production at relatively low costs. It is no coincidence that hydropower still dominates among eco-sustainable sources. Virtually inexhaustible, at least as long as there is a flow of water to exploit, hydropower is a safe energy source with “zero” environmental impact in many mountainous nations. For example, in the case of British Columbia, Canada, hydropower is responsible for almost 90% of the province’s electricity, much of it supplied by melted water from glaciers. Even in the European Alps and in some mountainous areas of Asia, glacial water plays a fundamental role in the production of hydroelectric energy.

Fig. 2: Centrale idroelettrica himalaiana “in sofferenza” a causa di assenza d’acqua
https://blogs.agu.org/landslideblog/2021/02/10/himalayas-1/

The erosion of glaciers, clearly influencing the quantity of water flowing downstream, represents a factor of worrying uncertainty regarding the production of energy through the exploitation of flowing water. Given the inability to plan how much water will melt from one year to the next, electricity production is strongly affected by periods in which there is overproduction, due to the presence of a lot of water, or a production crisis due to the almost total absence of flow. Situations of this type, according to various studies[5], have become increasingly recurrent in recent years, threatening in some areas – the Chilean Andes and the Indian side of the Himalayas – the supply of electricity to many families.

Glaciers contribute significantly to the production of new sediments; specifically, high mountain glacial areas can be responsible for disproportionately higher sediment flows than lower regions. In this regard, the uncontrolled melting of ice leads to a huge influx of rock material downstream that moves together with the water. When large glacial masses melt, much of the material follows the path traced by mountain watercourses. This phenomenon can promote the so-called silting up of reservoirs; this is one of the major problems in the management of artificial reservoirs, whether for energy or irrigation purposes. The progressive accumulation of sediment reduces the capacity of the reservoir and can limit its functionality, to the point of completely precluding it. It is therefore necessary for sedimentation in reservoirs to be controlled and limited, in order not to risk losing resources of high economic and environmental interest and damaging the water infrastructures responsible for the production of hydroelectric energy.

It should be emphasized that water erosion of the soil is a completely natural phenomenon, part of the morphogenetic processes that determine the evolution of the landscape, and as such cannot be eliminated. However, this process, if not kept under control, could cause serious damage and accelerate the wear of the systems. The deposition of the high solid content represented by the sediments has a direct impact, in addition to the reservoir capacity of the basin, on the maintenance, cost and effectiveness of the hydraulic works and mechanical devices of the artificial reservoirs. The accumulation of sediments increases the stress on the "dam body" and can also cause problems in the stability of the structure. The silting can also generate serious problems on the influent and effluent watercourses, as well as on the quality of the waters themselves and of the related ecosystems.

III. Uncertainty about glacier water flows for irrigation

The third major issue related to glacier erosion concerns the water supply for agriculture. Many mountain regions are experiencing a transition from predominantly snowfall to predominantly rainfed precipitation. This major change can lead to a short-term increase in flow, especially in winter or monsoon periods, but also to a lower storage capacity to buffer the reduction in flow in drier periods. Furthermore, changes in the timing of the onset and peaks of melting do not always coincide with peaks in demand. As a result, the phenomenon of melting glaciers clearly affects the amount of water resources intended for agricultural production. In fact, the water melted by glaciers and snow is a crucial source for irrigation in regions such as the Andes and South Asia. In the Himalayas, a mountain range that is essential for the water supply of billions of people, glaciers are melting rapidly with a rate of ice mass loss that many experts have called “exceptional”[6]. To put this loss into context, researchers estimate that between 390 and 586 cubic kilometers of ice have disappeared, or as much as is present today in the central Alps, the Caucasus and Scandinavia combined. This is a huge amount that in turn has contributed, through melting, to raising the sea level in the world between 0.92 mm and 1.38 mm.

With over 900 million inhabitants, the South Asian river basins of the Indus, Ganges and Brahmaputra are among the most densely populated areas in the world. The water supply of these areas depends largely on the melting of glaciers and snow in the Himalayas. Melt water is used to irrigate crops and provides farmers with sufficient water during periods of drought and low rainfall. Although there is general agreement that ice and snow volumes are essential for the water supply of South Asia’s river basins, until recently it was unclear how many people and how many irrigated fields actually depend on this source. Recent studies have shown that around 129 million farmers irrigate (largely or partially) their land using water from snow and mountain glaciers. Melt water alone provides enough water to grow food to support a balanced diet for several tens of millions of people. Changes in the amount of water available to farmers in Asia can cause unpredictable disruptions to water supplies and food production for many families.

Fig. 3: Bacino idrografico del fiume Indo
https://www.burningcompass.com/world/indus-river-map.html

Fig. 4: Bacini idrografici del Gange e del Brahmaputra
https://www.researchgate.net/publication/326831987_Hydrological_Impact_Study_of_Tipaimukh_Dam_Project_of_India_on_Bangladesh

Short and long-term solutions to counteract the negative effects of melting glaciers

The best solution to counteract the melting of glaciers would be to stop the rise in temperatures, that is, to positively resolve once and for all the age-old issue of climate change. While waiting to reach such a desired goal, it is appropriate to identify some strategies that can stop, or at least hinder, the progressive erosion of the "water towers". At present, there are some remedies proposed by researchers and experts to try to limit as much as possible the impacts that melting glaciers have on ecosystems and human communities.

A first short-term remedy would consist of the creation of numerous ice stupas. This is a particular technique for creating artificial glaciers, with the aim of combating water scarcity, especially in the Himalayan area. The peculiarity of these artificial structures is that they store melt water from snowfields formed during the winter (which would otherwise not be used), in the form of conical ice accumulations. During the hot seasons, when water is scarce, the ice stupa slowly melts naturally, increasing the availability of water supplies for the populations downstream. Invented by Sonam Wangchuk in Ladakh (India) as part of the project managed by the NGO Students’ Educational and Cultural Movement of Ladakh, this tool is the closest thing to the mechanism of natural melting of ice that occurs in the hot seasons.

Fig. 5: Esempio di stupa di ghiaccio sulle vette himalayane
https://www.handbookcostasmeralda.com/ice-stupa-fiabesche-torri-di-ghiaccio-per-vincere-la-siccita/

A second short-term remedy would be to create a supranational entity that ensures the reduced water availability for all populations downstream of the glacier. Given the importance that the “water towers” ​​play in the water supply during the warmer seasons, it would be desirable for them to become the available heritage of all human beings and not of some specific nations. To prevent the grabbing of melting glaciers from becoming a geopolitical challenge between countries that, against their will, find themselves sharing common mountain borders, it would be appropriate to establish as soon as possible an international authority with effective powers capable of limiting the claims of aggressive governments. This applies to all the great mountain ranges, from the Himalayas to the Andes, passing through the Alps and the Caucasus.

A third short-term remedy would consist in adopting a multidisciplinary approach to what concerns the studies on this topic. Multidisciplinarity could facilitate understanding on multiple levels and increase the urgency of public decision-makers in the development of new strategies. In this regard, one of the most important priorities for future research in this field is a better integration of social and other physical sciences with glaciological research, so that the results transcend disciplines and can more easily generate an impact. Water-related issues and, in particular, the complex issue of melting glaciers, are very complex. As such, it is appropriate to address them from an interdisciplinary and transdisciplinary perspective, also through the generation of data sets that go beyond traditional disciplinary boundaries and the application of methodologies that synthesize quantitative and qualitative data in a meaningful way.

Even in the medium-long term, a series of measures could be developed to limit the negative effects of melting ice. For example, once climate change is recognized as the primary cause of the progressive erosion of the “water towers”, it would be desirable to drastically and suddenly change the techniques with which we produce energy in order to lower temperatures over time. The use of fossil fuels, largely responsible for the excessive production of carbon dioxide, should be reduced through global strategies shared by all the main players on the international political scene. To do this, for example, we could incentivize the production of electricity through the exploitation of renewable sources or rely on nuclear energy, a powerful tool at our disposal capable of generating very high quantities of electricity with practically zero CO2 emissions. The nuclear fusion technique, specifically, guarantees a manipulation of the atom capable of satisfying the most demanding energy needs while producing limited waste, unlike, for example, the nuclear fission technique. An objection to this measure could be related to timing, given that in order to be able to rely on fusion we will have to wait a few more decades of technical and engineering developments. Nonetheless, given the great advantages that this technique is able to offer in various respects, it would be extremely useful to begin planning – as is already being done in some areas of the world – the progressive abandonment of fossil fuels with a view to more eco-sustainable energy production.

A second long-term remedy could be to limit as much as possible the construction of mega dams or large hydroelectric power plants that operate in mountain watercourses. As we have seen in this report, one of the main problems of melting ice lies in the transport of sediments and rock material downstream, which, over time, can cause serious damage to water structures, especially if large. A possible solution could be the construction of smaller but more numerous reservoirs, power plants and dams scattered along the entire path of the mountain river. Smaller structures generate less electricity but are more easily subject to rapid and correct maintenance, as well as having a lower economic impact during construction, and environmental, since a smaller dam generates less disruption to the ecosystem in which it operates. By virtue of this, the spread of the so-called mini-hydroelectric could guarantee a wiser and more careful exploitation of mountain watercourses, increasingly suffering due to the worrying thinning of glacial water reserves.

Finally, to counteract the reduced inflow of water from the glaciers it would be desirable to try to reduce as much as possible the use of water resources downstream. With a lower contribution from the glaciers it is unthinkable to continue to draw as if nothing had happened by the communities settled along the course of the glacial rivers. There are many strategies that could be adopted in this respect. For example, one could introduce crops that require little water to grow. In Asia, rice cultivation is widespread, a food that requires large quantities of water resources. It would seem wise to also include other foods that are decidedly more resistant to drought and less in need of water such as durum wheat, barley or oats. Furthermore, it could be useful to introduce irrigation techniques in which water waste is minimal, such as drip irrigation or Central Pivot Irrigation.

Bibliografia

• Cauvy-Fraunié S. & Dangles O., A global synthesis of biodiversity responses to glacier retreat, in “Nature Ecology & Evolution”, Vol. 3, pp. 1675 – 1685, 2019.

• Clason C., et. al., Contribution of glaciers to water, energy and food security in mountain regions: current perspectives and future priorities, in “Annuals of Glaciology”, pp. 1 – 7, 2023.

• Ford J. D., et. al., The resilience of indigenous peoples to environmental change, in “One Earth”, Vol. 2 N. 6, pp. 532 – 543, 2020.

• Hugonnet R., et. al., Accelerated global glacier mass loss in the early twenty-first century, in “Nature”, Vol. 592, pp. 726 – 731, 2021.

• Laurent L., et. al., The impact of climate change and glacier mass loss on the hydrology in the Mont-Blanc massif, in “Scientific Reports”, Vol. 10, pp. 1 – 11, 2020.

• Santofimia E., López-Pamo E., Palomino E.J., González-Toril E. and Aguilera A., Acid rock drainage in Nevado Pastoruri Glacier area (Huascarán National Park, Perú): hydrochemical and mineralogical characterization and associated environmental implications, in “Environmental Science and Pollution Research”, Vol. 24, pp. 25243 – 25259, 2017.

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[1] R. Hugonnet, et. al, Accelerated global glacier mass loss in the early twenty-first century, in “Nature”, Vol. 592, pp. 726 – 731, 2021.

[2] S. Cauvy-Fraunié and O. Dangles, A global synthesis of biodiversity responses to glacier retreat, in “Nature Ecology & Evolution”, Vol. 3, pp. 1675 – 1685, 2019.

[3] E. Santofimia, E. López-Pamo, E.J. Palomino, E. González-Toril and A. Aguilera, Acid rock drainage in Nevado Pastoruri Glacier area (Huascarán National Park, Perú): hydrochemical and mineralogical characterization and associated environmental implications, in “Environmental Science and Pollution Research”, Vol. 24, pp. 25243 – 25259, 2017.

[4] C. Clason et. al., Contribution of glaciers to water, energy and food security in mountain regions: current perspectives and future priorities, in “Annuals of Glaciology”, pp. 1 – 7, 2023.

[5] J.D. Ford, et. al., The resilience of indigenous peoples to environmental change, in “One Earth”, Vol. 2 N. 6, pp. 532 – 543, 2020.

[6] L. Laurent et. al., The impact of climate change and glacier mass loss on the hydrology in the Mont-Blanc massif, in “Scientific Reports”, Vol. 10, pp. 1 – 11, 2020.