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Glaciers and the water cycle – Nature's never-ending journey
Welcome to the World Water Day 2025 Activation Kit! This kit is designed to engage
you with fun facts, and interactive questions, while making you think about water’s
journey and the critical role glaciers play in the Earth's water cycle. We also reflect
upon the future and history of water while emphasizing the importance of water
recycling, both naturally and through human efforts!
What is the water cycle?
The water cycle is like Earth's recycling system! Water moves from the surface to the
sky and back again. This journey is made up of four stages: evaporation (water
turning into vapour), condensation (water vapour cooling to form clouds),
precipitation (rain, snow, or hail falling from the clouds), and collection (water
returning to rivers, lakes, oceans, and ‘aquifers’ underground). Every drop you drink
today has been part of this infinite journey for billions of years!
Fact: The same amount of water exists today as when Earth was formed – over 4.5
billion years ago! 1
Question:
• For the younger ones: What happens to water when it boils? Can you guess
which part of the water cycle makes clouds?
• For the older ones: How do you think the water cycle affects our weather and
climate?
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Evaporation and condensation: the cloud makers
Did you know that the sun is the engine behind the water cycle? It heats water from
the soil, oceans, lakes, and rivers, causing it to evaporate. When the water vapour
rises high into the air, it cools down and condenses into tiny droplets, forming clouds.
Sometimes, clouds gather so much water that they ‘burst’ – causing rain or snow to
fall back to Earth!
Fact: Did you know that clouds can weigh over a million pounds (about 500,000
kilograms)? This is because they are made up of countless tiny water droplets. When
they become too heavy, they release the water as precipitation! 2
Question:
• For the younger ones: Why do you think clouds are important for the water
cycle?
1 This is based on the concept of the water cycle, which continually recycles water through evaporation, condensation, and
precipitation. This process has been happening for billions of years, meaning Earth's water is as old as the planet itself
(UNESCO), and UN World Water Development Report 2021, Chapter 1: The World's Water Resources (UN-Water/UNESCO).
2 This is based on “How Much Does a Cloud Weigh?” by the United States Geological Survey. (USGS)
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For the older ones: How do changes in temperature and humidity affect the
formation of clouds and precipitation? How does the process of evaporation
and condensation help in distributing fresh water across the planet?
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Precipitation and collection: water returns to Earth
When clouds get heavy, gravity pulls the water back to Earth in the form of
precipitation. Depending on the temperature, this can be rain, snow, sleet, or hail.
After it falls, the water collects in aquifers, rivers, lakes and oceans, starting the cycle
all over again.
Fact: Nearly 97 per cent of Earth’s water is salty or undrinkable. Only 3 per cent is
fresh, and two-thirds of that is frozen in glaciers or otherwise inaccessible. 3
Question:
• For the younger ones: Next time it rains, think about where that water has been
on its journey across the planet! Could you make a drawing, poem or song
about this journey with your friends?
• For the older ones: What are some ways we can conserve and protect the
small percentage of fresh water available to us?
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The role of glaciers: Earth's frozen ‘water towers’
Glaciers are giant frozen reservoirs of fresh water. They store about 70 per cent of
Earth’s fresh water. During warmer seasons, glaciers slowly melt, releasing water
downstream. In many parts of the world, this helps keep water flowing in places that
might otherwise dry up. Glaciers are also crucial for regulating Earth’s climate.
However, because of climate change, glaciers are melting faster than ever, which
could change the water cycle in ways that can affect people and the environment.
Fact: Glaciers move! Though they seem still, glaciers slowly slide downwards across
the land, shaping valleys and mountains as they go. Some glaciers can move up to
30 metres a day – about the length of three school buses! 4
Question:
• For the younger ones: What do you think happens to rivers and lakes when
glaciers melt faster?
• For the older ones: How do melting glaciers affect sea levels, and what impact
could this have on coastal communities?
3 According to the United Nations' World Water Development Report 2018, about 97 per cent of Earth's water is in oceans
and seas, and only 3 per cent is fresh water, most of which is locked in glaciers, ice caps, or deep underground. (UNWater/UNESCO).
4 Glaciers are dynamic and move due to the pressure of their own weight. They can flow at speeds of up to 30 metres a day
in some cases. This movement shapes the landscape, creating valleys, fjords, and moraines (UNESCO) (National Snow and
Ice Data Center (NSIDC): "How do glaciers move?").
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Water: a time traveller!
Did you know the water we use today is the same water that existed when dinosaurs
roamed the Earth? Water is constantly recycled – whether through natural processes
like the water cycle or by humans using treatment plants to clean it. So, every drop of
water you use might have been part of a prehistoric river or even a dinosaur’s drink
millions of years ago!
Fact: Water treatment plants speed up nature's purification process to make water
safe for us to drink.
Question:
• For the younger ones: Can you imagine sharing a glass of water with a
dinosaur? How do you think water treatment helps keep it clean for us today?
• For older ones: What role does water treatment play in ensuring sustainable
water supplies for growing populations?
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Glaciers as climate record-keepers
Glaciers are more than just frozen water – they are natural archives of Earth's climate
history! Each layer of snow and ice that builds up over time traps small bubbles of air,
pollen, dust, and other particles, preserving valuable information about past climates.
By studying these layers, scientists can learn about Earth's temperature, atmosphere,
and even volcanic eruptions going back thousands of years.
Fact: Some ice cores from glaciers hold climate records as far back as 800,000
years! These ‘ice time capsules’ help scientists understand the cycles of warming
and cooling Earth has gone through.
Question:
• For the younger ones: Imagine if each layer of ice was a page in Earth’s history
book! What kind of secrets do you think glaciers might hold?
• For the older ones: How can studying glacier ice cores help us predict and
prepare for the impacts of current climate change trends?
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Glaciers and climate change: why we must act now
Glaciers are some of the most important sources of fresh water on Earth, but they
are melting rapidly due to climate change. As global temperatures rise, glaciers lose
mass, contributing to sea level rise and threatening water supplies for billions of
people. If we don't act to reduce greenhouse gas emissions, this trend will worsen,
leading to more extreme weather, flooding, and water shortages.
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By limiting global warming to 1.5°C, we can help slow the melting of glaciers and
preserve these vital water sources. Adapting to the changing climate is also crucial –
this means building better water management systems and preparing communities
for changing water availability.
Fact: If all the world's glaciers melted, sea levels could rise by over 60 metres 5 (197
feet), which would drastically change coastlines and flood entire cities!
Question:
• For younger ones: How can we help protect glaciers by saving energy and
using renewable resources like solar power?
• For older ones: Why is it important to reduce greenhouse gas emissions to
slow glacier melt, and what role can you play in the fight against climate
change?
Contact us!
Would you like to share your answers or actions taken on #WorldWaterDay?
You can contact us on: campaigns@unwater.org mentioning [World Water Day]
in the subject heading. Thanks for learning more about water’s journey and the
critical role glaciers play in the Earth's water cycle!
5 According to the United Nations Intergovernmental Panel on Climate Change (IPCC), if all land ice melted, it would result
in an estimated sea level rise of approximately 60 to 70 metres (UNFCCC) (World Meteorological Organization) (UNESCO)
(IPCC AR5 Climate Change 2014: Impacts, Adaptation, and Vulnerability). Additionally, reports from NASA and UNESCO
highlight similar projections (UN Press).
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