Ailing Glaciers: Aerosol Warming the Himalayas- Insights from Prof. Naresh Chandra Pant on Glaciers, Air Pollution and Climate Change

Abstract: The Himalayan glaciers face significant climate change and air pollution threats. In  this episode of GnY-Live, Professor N C Pant, a renowned geologist and a cryospheric expert,  discusses the impact of air pollution on glaciers, particularly in the Himalayan and Tibetan  Plateau regions, with Dr Sulagna Chattopadhyay, Editor-in-Chief, GnY. Professor Pant explains  aerosols—fine particles in the atmosphere—affect the health of glaciers and contribute to global  warming. Beyond the impact of carbon dioxide, aerosols increase heat retention in the  atmosphere by as much as 50 percent. Also, Prof Pant adds that 75 percent of the Himalayan  glaciers have retreated in the past century, with aerosols exacerbating this trend. However, the  Himalaya reacts differentially to warming, where the eastern glaciers display less retreat than the  western glaciers. Professor Pant explains the role of human activities, such as mining and  industrial emissions, in exacerbating these environmental issues and highlights the consequences  for communities dependent on glacial meltwater, especially in regions like Punjab. The  discussion emphasises the urgent need for sustainable practices, better scientific research, and  more effective pollution management strategies. The episode underscores the importance of  collective efforts to mitigate the environmental impact and preserve vital natural resources. 

Keywords: Himalayan Glaciers, Tibetan Plateau, Third Pole, aerosols, cryoconite, climate  change, glacial retreat, global warming, remote sensing, wet mining, sustainable mining, health  impacts

Introduction 

The Himalayas, often referred to as the ‘Third Pole’[1] due to their vast ice reserves, are facing a  growing environmental crisis that threatens not only the region but also More than 1.9 billion  people who rely on the water that flows from the glaciers, whether for drinking, agriculture,  energy, or other purposes[2]. In this episode of GnY-Live, we examine the impact of air pollution  and aerosols on the health of Himalayan glaciers, featuring expert insights from Professor Naresh  Chandra Pant, a distinguished geologist. Professor Pant provides a comprehensive analysis of the  complex interplay between aerosols, glacial dynamics, and global warming, highlighting the role  of anthropogenic activities, such as mining and industrial emissions, in accelerating the retreat of  these glaciers. As the glaciers melt away, the repercussions on regional river systems, local  communities, and surrounding ecosystems are becoming increasingly severe[3]. This episode  emphasises the critical need for sustainable practices, collaborative scientific research, and  effective pollution management strategies to mitigate further environmental deterioration. The  discussion underscores the urgency of preserving the Himalayan glaciers as vital natural  resources and the need for global efforts to prevent their irreversible decline. 

This episode offers a scientific exploration of the ongoing crisis facing the ‘Third Pole’,  presenting both the challenges and potential solutions to mitigate the melting of the glaciers and  safeguard the environmental and socio-economic stability of the region. 

GnY: What is the ‘Third Pole’? 

The term ‘pole’ typically refers to the high latitudes near the geographic North and South Poles.  While the Himalayan region is at a much lower latitude, it is referred to as the ‘third pole’ due to  the combined presence of a large expanse of ice and 1/6th of the world’s population inhabiting it,  making it vulnerable to climate change impacts. Antarctica holds around 30 million cubic km of  ice[4], while the Himalayan region contains only about 7,000 cubic km[5]. Despite this difference,  the Himalayan ice is vital because of its critical influence on such a large population, making it  appropriate to call the Himalayan region the ‘third pole’[6]. 

GnY: But can dirty air from the Indian sub-continent reach as far as Antarctica? We’re  hearing reports about this—are you sure, Professor? Can the activities in the plains impact  the glaciers in the Himalayas? 

Air has an incredible ability to travel vast distances, connecting even the farthest parts of the  planet. The atmosphere comprises layers, and the stratosphere[7]—ranging from 6-12 km above  the surface to about 50 km—plays a key role in this. 

Activities near the equator or even in high-altitude regions like the Tibetan Plateau, around 4,000  m above sea level, can send pollutants horizontally across continents and vertically into higher  atmospheric layers. Evidence shows these pollutants can travel to high latitudes and as far as  Antarctica. This movement has wide-ranging impacts, from influencing cloud formation and  weather patterns to carrying harmful materials that affect health and ecosystems. 

GnY: How do the pollutants move through the atmosphere to all these faraway places? 

The pollutants move with the air circulation patterns, which are influenced by factors like Earth's  rotation, temperature variations, and even space weather—the effects of space beyond Earth on  our atmosphere. It is a complex interplay of many forces[8].

At the same time, the effects of this movement are noticeable in different ways. Aerosols are  very fine particles, usually <1 one micron, which is 1,000th of a millimetre. They can be solid  particles or even liquid droplets, affecting us in many ways. 

GnY: What is the composition of this ‘dirt’ or aerosols in the air? Don’t aerosols help cause  rain? 

Aerosols can impact cloud formation in different ways[9]. For example, when there’s a volcanic  eruption, like in Italy or Indonesia, the material released includes fine particles, some of which  are aerosols. These fine particles, along with gases like sulfur dioxide droplets, can reach higher  altitudes. However, the natural sources of aerosols—like volcanic eruptions—are beyond our  control; the human-made or anthropogenic sources are something we can address. These sources  of pollution have significant implications, especially for future generations. Understanding this is  crucial for how we approach solutions to mitigate such impacts. 

GnY: There are reports of holes appearing on glaciers, and polluted air is said to be  causing this. Are these holes turning glaciers black, like how pollution affects our lungs?  Are glaciers also ‘falling ill’? 

These holes, called cryoconites[10], are found on glaciers worldwide, from the Himalayas to  Antarctica and the Arctic. Initially, they were thought to be insignificant, but research has shown  they are more important than we realise. 

Cryoconites are circular, cylindrical holes filled with sediments, which are carried by the wind  from distant places. In places like Antarctica, these holes are formed in pristine white ice, and the  particles within them create a unique ecosystem. This deposition of matter also leads to  biological activity in the cryoconites, which is a new area of study. 

The darker sediments in these holes cause the ice to absorb more heat, speeding up the melting  process. Thus, cryoconite impacts not only the health of the glaciers but also the surrounding  ecosystem, making it a crucial factor in understanding glacier changes. 

GnY: Are we seeing an increase in these holes in the glaciers in the context of climate  change? 

The issue isn’t so much about understanding the process but rather about having accurate data  with fewer errors. These changes are definitely happening, but the extent of their impact is still  uncertain. 

A recent study by our PRL group revealed that aerosols could be responsible for up to 50 per  cent of the warming in regions like the Indo-Gangetic plains, the Himalayas, and the Tibetan  Plateau[11]. While most people tend to focus on carbon dioxide as the primary contributor to  global warming, aerosols also have a significant impact. 

Three methods for studying this are direct observation of particles, remote sensing (like  MODIS[12]), and modelling. Each approach provides valuable insights but also has a high margin  of error. This is why we cannot be entirely definitive about the effects. While the harmful  impacts of aerosols are clear, we need more research, better data, and a combination of these  three methods to fully understand the scale of their impact. 

GnY: Are the Himalayan glaciers retreating, and what will be the impact on river systems?  Is air pollution a contributing factor?

Aerosols from natural and human-made sources contribute significantly to climate change. Rapid  population growth and development have altered ecosystems and accelerated global warming,  which, combined with aerosol emissions, is causing the retreat of Himalayan glaciers. About 75  per cent of the Himalayan glaciers are currently receding. These glaciers supply water to major  river systems like the Ganges, Indus, and Brahmaputra, which affect 1.4 to 1.5 billion people  across multiple countries in the region. 

Air pollution, particularly aerosols like black and brown carbon, accelerates glacier melting by  increasing heat absorption. The effects on river systems will vary, with regions like Punjab, more  reliant on glacier melt, being more affected than areas like Arunachal Pradesh[13]. Changes in  river flow may initially increase due to higher precipitation but could decrease over time as  glaciers continue to shrink. 

GnY: What key solutions do you propose to address the growing environmental challenges,  especially the impact on glaciers? 

To address the growing environmental challenges impacting glaciers and ecosystems, a three point solution focused on sustainable living can be outlined: 

1. Good Science: Accurate data and a clear understanding of climate change are  fundamental. Solutions can be more effective by improving climate modelling and  reducing errors in data collection. 

2. Reducing Pollution: To mitigate climate change and its impact on ecosystems, it is  critical to tackle both greenhouse gases and aerosols. A comprehensive approach is  required, considering all sources of pollution, including industrial emissions and  agricultural practices, such as pesticide use, which contributes to aerosol formation. 

3. Managing Population: Rapid population growth in the Indo-Gangetic plains is a major  driver of environmental degradation. Managing population dynamics ensures that  resources are not over-exploited, helping to create a more sustainable balance with the  planet’s ecosystems. 

These interconnected actions—good science, pollution reduction, and managing population — are key to mitigating climate change and its adverse effects on glaciers and the environment. 

GnY: What are your thoughts on the management aspect? 

The management system in India has a significant flaw in its limited collaboration between  experts from different fields, hindering effective problem-solving. Increasing expert interaction  over bureaucratic processes can address this lack of cross-disciplinary communication.  Additionally, local communities, the primary stakeholders in environmental action, need to be  involved in the solution. For example, wet mining could significantly reduce dust pollution and  health impacts in Rajasthan. However, local communities often prioritise immediate livelihood  concerns over environmental risks. By understanding the long-term health benefits of alternative  methods, they may be more open to making small, cost-effective changes that improve their  well-being. 

Conclusion 

The preservation of the Himalayan glaciers is vital not only for the region's ecosystems but also  for the livelihoods of billions of people. The retreat of these glaciers has far-reaching  consequences for regional river systems, which millions of people depend on for water. The 

urgent need for comprehensive solutions is straightforward. Effective pollution management,  improved scientific research, and sustainable practices are critical in mitigating these challenges.  Addressing population growth and promoting cross-disciplinary collaboration can also help find  more effective solutions. Engaging local communities and educating them on the long-term  benefits of environmental conservation is essential for fostering sustainable change. 

References 

[1] Meloth, T., & Sharma, P. (2019). Third pole on thin ice. Geography and You. 28 April,  2019.https://geographyandyou.com/himalayan/third-pole-on-thin-ice 

[2] Global Citizen. (n.d.). Billions rely on Himalayan glaciers for water. But they're  disappearing. Retrieved January 24, 2025, from  

https://www.globalcitizen.org/en/content/himalayas-melting-climate-change/ [3]Chandrashekhar, V. (2022, October 3). As Himalayan glaciers melt, a water crisis looms in  South Asia. Yale Environment 360. Retrieved January 24, 2025,  

fromhttps://e360.yale.edu/features/himalayas-glaciers-climate-change 

[4] British Antarctic Survey. (n.d.). Antarctic ice sheet. British Antarctic Survey. Natural  Environment Research Council. Retrieved January 23, 2025,  

fromhttps://www.bas.ac.uk/about/antarctica/geography/ice/ 

[5] World Bank. (2019). Glaciers of the Himalayas: Climate change, black carbon, and regional  resilience. Retrieved  

fromhttps://documents1.worldbank.org/curated/en/976841622778070962/pdf/Glaciers-of-the Himalayas-Climate-Change-Black-Carbon-and-Regional-Resilience.pdf 

[6] Pant, N. C., Ravindra, R., Srivastava, D., & Thompson, L. (2018). The Himalayan cryosphere:  Past and present variability of the 'third pole'. Geological Society of London Special  Publications, 462, 13-28.https://doi.org/10.1144/SP462.13 

[7] Brasseur, G. P., Smith, A. K., & Granier, C. F. (1993). The Stratosphere: An Introduction.  In The Role of the Stratosphere in Global Change 8, 1–10. https://doi.org/10.1007/978-3-642- 78306-7_1 

[8] National Geographic. (n.d.). The Coriolis effect. National Geographic. Retrieved January 23,  2025, from https://education.nationalgeographic.org/resource/coriolis-effect [9] Sarangi, C., Tripathi, S. N., Kanawade, V. P., Koren, I., & Pai, D. S. (2017). Investigation of  the aerosol–cloud–rainfall association over the Indian summer monsoon region. Atmospheric  Chemistry and Physics, 17(8), 5185–5204.https://doi.org/10.5194/acp-17-5185-2017 

[10]A cryoconite is a small pile of dark, dusty material made up of windblown particles like rock  dust, soot, and microbes that accumulates on glaciers, usually settling at the bottom of small  depressions called "cryoconite holes"; essentially, it's like a tiny dirt patch on the ice that can  contain a small ecosystem of microorganisms. 

[11] Ramachandran, S., Rupakheti, M., Cherian, R., & Lawrence, M. G. (2023). Science of The  Total Environment, 894, 164733.https://doi.org/10.1016/j.scitotenv.2023.164733

[12] NASA. (n.d.). MODIS: Moderate resolution imaging spectroradiometer. Retrieved January  23, 2025, fromhttps://modis.gsfc.nasa.gov 

[13] Kumar, R., & Singh, R. (2020). Impact of climate change on water resources in the Indian  Himalayas: A study of the river systems. Environmental Science and Policy, 115, 128-139.  https://doi.org/10.1016/j.envsci.2020.09.007