In December 2022, the United Nations General Assembly declared 2025 as the International Year of Glacier Conservation, which is why in this article we want to tell you about some characteristics of glaciers and reflect together on their importance for our planet.
What are glaciers?
Glaciers are permanent bodies of ice and snow which have been formed by the accumulation, compaction and recrystallisation of snow over thousands of years. In areas with very cold climates, snow falls in winter and accumulates from year to year, when it fails to melt in summer. Over time, pressure transforms the snow into dense ice. Despite appearing static, glaciers flow slowly due to gravity. Some advance only a few centimetres a year, while others can move several metres a day.
Where are they located?
This curious phenomenon does not occur just anywhere, but only in cold, high mountain regions. The largest and most representative glaciers in the world are found in five regions:
- Antarctica and Greenland: This area is home to the largest ice masses on the planet. Antarctica alone contains approximately 70% of the world's frozen fresh water! This ice mass occupies an area of about 26.5 million km³, which is a lot! If all this ice were to melt, the sea level would rise by 58 metres. Greenland, on the other hand, has about 2.85 million km³ of ice, which is equivalent to about 6-7% of the world's fresh water.
- Himalayas: The Asian mountain range contains glaciers that are home to approximately 4,000 km³ of freshwater. Meltwater from these glaciers feeds major rivers such as the Ganges, Yangtze, Brahmaputra and Indus that provide freshwater for millions of people.
- Rocky Mountains and Alaska: In North America, these regions have numerous glaciers containing more than 1,200 km³ of water.
- Andes Mountains (Patagonia): In South America, especially in Argentina and Chile, there are the Patagonian glaciers, which store about 500 km³ of water. Among these, the Southern Patagonian Ice Field and the Perito Moreno Glacier stand out.
- Alps and other mountain ranges in Europe: Although smaller than the above, alpine glaciers play a crucial role in freshwater supply as they store approximately 130 km³ of ice. Unfortunately they are also retreating, having already lost almost 50% of their volume in the last century.
Why are they so important?
Glaciers are strategic water reserves, although the planet is mainly made up of water (70% of the earth's surface), only 2.5% of it is fresh and, of this amount, approximately 70% is frozen in glaciers, ice caps and permanent snow. This makes glaciers the most important reservoir of accessible freshwater we have.
They are essential for the regulation of river flows, especially in drought years. Their thawing contributes to water supply in arid areas, minimising impacts on socio-economic activities. They are of great scenic and tourist value, attracting thousands of visitors each year.
They reflect excess heat back into space and keep the planet cooler. Their white, extensive surface reflects solar radiation, contributing to the planet's thermal balance and mitigating the effects of global warming. In addition, glaciers function as natural laboratories for scientific studies and are key indicators of climate change, as their retreat is evidence of global warming.
They regulate sea levels and protect the planet. When glaciers melt, they release water that forms downdrafts that contribute to sea level rise.
They are fundamental to the development of life on Earth, support biodiversity and are important for the survival of many animals, such as polar bears and penguins.
Why are glaciers in danger?
In 2024, global average temperatures exceeded 1.5 degrees of warming since pre-industrial times, and this rise in temperatures is causing an alarming retreat of glaciers. Some scientific findings warn that more than 80% of the world's glaciers could disappear by the end of the century if the current rate of greenhouse gas emissions continues. Melting glaciers have catastrophic consequences for water supply and ecosystem stability.
Among the activities that most threaten glaciers we can recognise the high emission of greenhouse gases, which occurs mainly through the burning of fossil fuels. Mining, deforestation and urbanisation modify the hydrological cycle, altering the flow of the rivers that feed the glaciers. In addition, mining also causes significant pollution as, besides destroying ecosystems, it can contaminate water with heavy metals and deposit black carbon (soot) on glaciers. This reduces their white surface and accelerates melting because it increases heat absorption.
What can we do to protect glaciers?
Unfortunately, we cannot reverse the damage already caused, but we can act to build a better future, taking care of the ones we still have. It is important to reflect on the fact that when a glacier disappears it cannot be replaced, that our actions have environmental impacts that we often do not imagine. Therefore, it is essential that we become aware and try to reduce our carbon footprint, save water, avoid over-consumption and be more conscious when buying and throwing away, try to recycle and reuse things, etc. Simple actions that can generate, if they become collective, an important change that benefits us all. Building a more sustainable world is our responsibility.
Ing. Agr. Porporato Andrea
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