Introduction

Glaciers are slow-moving rivers of ice, free-flowing down due to the force of gravity. They are also a fundamental element in the water cycle as they represent the largest storage of fresh water on earth; roughly 68.7% are locked up in the world’s icecaps and glaciers. (History, 2016)

There are two types of glaciers: cold-based and warm-based. Both have been given distinct names due to the regions they are found in.

• Warm-based glaciers are in alpine regions such as the Himalayas and the American Rockies. Warm-based glaciers advance through the process of basal slip, which is the movement of ice sliding over the bedrock due to the meltwater, which acts as a lubricant. Warm-based glaciers go through two phases: advancement and retreat. A warm-based glacier advances during the winter months as the glacial budget (the difference between accumulation and ablation) is in favour of accumulation as most of the precipitation that falls on the glacier is in the form of snow. Compared to

• Cold-based glaciers are found in regions such as Antarctica and Greenland where the temperature remains below freezing all year. As a result of the freezing temperatures, they move much slower than the warm-based glaciers. They do not move as a result of lubrication by the melting of glacial ice rather than a process called “Internal Deformation/flow. Due to the extremely low temperatures, the glacier’s base freezes to the bedrock, but the effects of gravity are still present. The force that gravity exerts on the ice causes it to move. The ice crystals react under pressure, deforming them. Thicker and warmer ice deforms more rapidly.

Role to tackle climate change

Glaciers play a factor in the reduction of climate change. They do this by reflecting the sun’s radiation into space. This effect is called “the albedo effect,” which for snow and glacial ice is high due to its white or blue appearance. Given that 11% of the earth’s land surface is covered in ice and snow, this makes a huge difference in the fight against climate change. (USGS, 2023) However, as a result of rising temperatures, larger amounts of ice and snow are melting, and when this happens, small pieces of dirt are left on and around the glacier. This material was captured when snow fell tens of thousands of years ago and has been trapped in the ice ever since. The darker appearance of this dirt has a lower albedo; therefore, it absorbs more of the sun’s heat, melting more ice, and creating a negative feedback cycle.

Methods such as placing white covers over ski resorts in the Alps have been implemented to reduce ice loss during the summer. (Brown, 2022) Other methods have been to use large fans that spray a fine mist that freezes, covering the land in a blanket of snow, to help reduce melting.

Glaciers also allow scientists to understand the earth’s climate up to 800,000 years ago. (Bauska, 2022) They do this by taking ice cores from either Greenland or Antarctic ice sheets, as this is where the world’s oldest ice is found. As snow accumulates over time, pockets of air remain inside it, and as more and more snow builds up over time, the air is squeezed out. But some pockets remain embedded in the ice after thousands and sometimes millions of years. Scientists use large drills to dig deep into the ice and take what is known as an ice core. Once removed, the ice cores are taken to laboratories, where small air pockets are extracted and analysed to see the Earth’s atmospheric composition at the time. This provides some of the best evidence for climate scientists to show world leaders and the general public to convince them that climate change is an anthropogenic effect that is only getting worse.

Life given water

Glaciers contain vast amounts of frozen water and therefore provide a lifeline to millions of people around the world. 26% of the global watersheds outside Antarctica and Greenland are supplied by the waters of melting glaciers. The five basins of the Indus, Ganges, Yellow, Brahmaputra, and Yangtze are home to 1.4 billion people or over 20% of the world’s population.

Due to the ever-increasing global temperatures, the demand for freshwater has increased, and the replenishing precipitation has become less reliable due to climate change. These stores of water act as a safety net during extreme periods of hot weather. However, this luxury will not be here forever, as the glacial budget will swing more to the ablation side of the scale as temperatures increase.

Countries such as India and Pakistan rely heavily on glacial meltwater to replenish their rivers supplies during the summer months. This region has a certain period where most of its year’s rain falls; this is called the monsoon season, which normally occurs from June to September (though this will most likely change because of climate change). The Himalayas are in the north of both countries; therefore, most of the rain that falls on these peaks must flow through both Pakistan and India, mostly through the Indus and Ganges River systems, respectively. The waters from these rivers are used for several things.

• Highways for trade
• Sewage
• Religious reasons
• Drinking water
• Agriculture
• Industry

During times of little precipitation, the region relies on the melting of glacial ice high up in the mountains to supply the water needed for the countries’ economies to function. The Himalayas are home to around 32,392 mountain glaciers, from the Fedchenko Glacier, the longest valley glacier in the world (70 km), to the world’s highest glacier, “Khumbu Glacier,” which flows down from the slopes of Mount Everest. (A. K. Sharma, 2013) Just like the waters from the monsoons, the glacial meltwater will flow down the same channels. However, the Himalayan glaciers are melting at an increasingly faster rate because of climate change.

Biodiversity

The waters are not just essential for use in our homes and industries but also in ecosystems. An example of this is the Lyell Glacier in the Sierra Nevada Mountain range in California. During the summer, the meltwater from the Lyell Glacier keeps the Tuolumne River at a suitable level to support the vast ecosystems of Yosemite National Park. Yosemite is one of America’s most visited national parks, with some of the country’s most beautiful natural phenomena, from Yosemite Falls to Half Dome. It also has 704,624 acres of wilderness, which contains some of North America’s most well-known animals, such as black bears, mountain lions, and bald eagles. In addition, the whole of Yosemite’s wilderness has approximately

• 90 mammal species
• 262 species of birds
• 22 reptile species, including one turtle, seven lizards, one skink, and 13 snakes
• 11 native and one non-native amphibian species
• Nine non-native fish species exist in Yosemite, including bluegill, smallmouth, five trout species, and two trout hybrids.
• 30,000 species of arthropods, which include insects, spiders, scorpions, millipedes, ticks, crustaceans, and many other animals.

Source : (National Park Service , 2017)

As is common knowledge, all life needs water, especially during the height of summer when the ever-depleting winter snowpacks thaw out. The Lyell and its sister glacier, the Maclure Glacier, have become one of the only water sources for miles around, and they are used to support wilderness biodiversity. However, like all glaciers on earth, both the Lyell and Maclure Glaciers have reduced significantly, and now a report from 2013 says the Lyell Glacier (the largest of the two) can no longer be classified as a glacier as it has lost all movement and is now referred to as an ice field. (National Park Service , 2013)

All biotic things require water to survive, and the food chain needs a large variety of animals and plants to create a more stable planet/ecosystem. Furthermore, nutrients and energy security are also tied to having high biodiversity. As well as the development of medicines and pharmaceuticals. Finally, you have freshwater security, as areas with high biodiversity, like forests, are terrific at storing water as the ground acts like a sponge.

The threat they pose

One of the most well-publicised effects of climate change is sea level rise. The doomsday glacier is the nickname given to the Thwaites Glacier in Antarctica. It has been given this name because if it were to melt, sea levels across the globe would rise by 2 feet. I am sure you have heard figures like this before. So why is this glacier different? The Thwaites glacier extrudes into the sea, creating an ice shelf. Over the past decades, warmer-than-expected ocean currents have been slowly undercutting the glacier and are now close to the point where the glacier is resting on bedrock. If or when that part of the glacier melts, the warmer water will be able to flow downhill along the bedrock directly under the glacier. This would cause a large amount of ice in the glacier to become unstable and at risk of collapsing. Therefore, the Thwaites Glacier is one of the most heavily monitored glaciers in Antarctica.

Conclusion

In this day and age, glaciers are some of the most vital natural phenomena we have. From their life-giving water to their habitats and reflective nature. Their presence is felt by over 1.4 billion people around the globe. However, the current predictions indicate that nearly half of the world’s mountain glaciers will disappear by the end of the century, and that is in the best-case scenario regarding climate goals (Harvey, 2023). Therefore, as the years progress, the importance of these glaciers will become more and more apparent.

References

A. K. Sharma, S. K. (2013). Glacier Inventory in Indus, Ganga and Brahmaputra Basins of the Himalaya. Prayagraj: Springer.

Bauska, T. (2022, June 30). Ice cores and climate change. Retrieved from British Antarctic Survey: https://www.bas.ac.uk/data/our-data/publication/ice-cores-and-climate-change/

Brown, T. (2022, July 26). Swiss mountain is covered with a BLANKET to stop snow melting near ski resort – as Alpine glaciers vanish at their fastest ever rate following record heatwaves. Retrieved from Mail Online: https://www.dailymail.co.uk/news/article-11049173/Swiss-mountain-covered-BLANKET-stop-snow-melting-near-ski-resort.html

Duncan, J. (2011, August 24). Redrawing the Map of the World’s International River Basins. Retrieved from NewSecurityBeat: https://www.newsecuritybeat.org/2011/08/redrawing-the-map-of-the-worlds-international-river-basins/

Harvey, C. (2023, January 9). Half of All Mountain Glaciers Are Expected to Disappear by 2100. Retrieved from Scientific American : https://www.scientificamerican.com/article/half-of-all-mountain-glaciers-are-expected-to-disappear-by-2100/#:~:text=Nearly%20half%20the%20world%27s%20mountain,its%20most%20ambitious%20climate%20goals.

History, A. M. (2016). Where is Earth’s Water? Retrieved from American Museum of Natural History: https://www.amnh.org/content/download/154153/2561707/file/grace-curriculum-student-passage1.pdf

National Park Service . (2013, September 11). Lyell Glacier. Retrieved from National Park Service : https://www.nps.gov/yose/blogs/lyell-glacier.htm

National Park Service . (2017, January 19). Animals . Retrieved from National Park Service : https://www.nps.gov/yose/learn/nature/animals.htm#:~:text=Yosemite%20National%20Park%20supports%20more,Yosemite%20that%20are%20largely%20intact.

USGS. (2023). How does present glacier extent and sea level compare to the extent of glaciers and global sea level during the Last Glacial Maximum (LGM)? Retrieved from United States Geological Survey.: https://www.usgs.gov/faqs/how-does-present-glacier-extent-and-sea-level-compare-extent-glaciers-and-global-sea-level#:~:text=Today%2C%20glaciers%20cover%20approximately%3A,11%25%20of%20Earth%27s%20land%20area