SCIENCE TUTORIALS

Earth’s Ultimate Recycling System: The Water Cycle

Earth Science Introductions

Photo by Wesley Tingey on Unsplash

If you’re new here, I am not a science expert. I’m just a neurodivergent woman with special interests and currently middle school Earth Science is it. Previously, it was astronomy. While Earth Science can be included in astronomy, we are focusing on the planet Earth itself here, and as always, if you are a scientist and I make a mistake, please gently correct me in the comments so readers will know. I also add a list at the end of these articles with my references and further reading, should you choose. Thanks, and let’s dive in!

Water doesn’t disappear. It keeps moving and goes through time and space, like an ultimate Earth recycler.

Water Never Dies! It transforms!

The water cycle is another of Earth’s recycling systems. Water constantly changes forms but never truly disappears. (Why am I thinking of a movie with Bruce Lee and the “Be like water” phrase?) Every water molecule on the planet today has been here since the beginning of Earth. These water molecules are time travelers, moving from oceans to sky to underground tunnels and back again.

The water you use in your shower could have been used by Ancient Romans to drink. It could have been in the ocean during the Golden Age of Piracy in the 1700s, or various other times in the past.

The Routes of the Water Cycle

The journey of water involves key pathways for it to travel and transform.

Evaporation: The Sun sends energy to the Earth. When the Sun’s energy hits the water, the molecules in the water break free and go up, like invisible water vapor. Oceans, when the Sun touches them, release trillions of gallons of water into the air every single day.

Transpiration: Plants suck up the groundwater through their roots and release it through tiny pores in their leaves. A single oak tree can pump 100 gallons of water into the air each day!

Condensation: When water vapor rises into the air, it cools down and transforms back into liquid droplets, forming clouds. When these droplets get too heavy, they fall as precipitation (rain, hail, snow) that covers the land. After precipitation hits the Earth, it splits into different paths. Some water seeps into the ground through infiltration; it goes underground for long periods of time. Think centuries. Other water acts as runoff which can carve canyons, and feed rivers, eventually returning to ocean basins. (I’m drinking water as I’m typing this.)

Water Cycle is a Hero?

Without the water cycle on Earth, life as we know it would not exist. The water cycle delivers fresh water to ecosystems worldwide, powers weather systems and helps regulate the temperature of the planet.

During evaporation, water absorbs heat like a sponge and carries that heat energy into the atmosphere. When the water condenses later, it releases that heat and creates a global air conditioning system that helps keep Earth livable.

Human bodies are part of the water cycle. Each time a human breathes out (exhales), tiny water droplets join the atmosphere. (PTSD from Covid anyone?) When humans sweat, that is also adding to the water cycle.

Morning dew on blades of grass is condensation in action. The creek that rushes after a storm, that water is runoff carving a path. When puddles disappear in the parking lot or on the sidewalk, that is evaporation in progress.

The water cycle is a complex transportation network with express routes and long detours. Some water molecules can complete their journeys in days. Others get trapped in glaciers, or deep underground for 1000s of years. (I’m thinking of all the unknown germs and diseases in glaciers that are melting. Yikes!)

The Water Cycle is Changing

Humans are rewiring parts of this cycle. (We really are a virus. Parasite? You decide.) As Earth warms, evaporation accelerates, supercharging some parts of this cycle. It creates a form of weather whiplash. Some regions drown in record floods. Other regions experience severe droughts. (Scary stuff…)

When you understand how the water cycle works, you now have power to protect this resource. Humans can recycle and do other things with water, that I will not cover here because we all should know it by now.

Interesting Facts

1. A single raindrop might stay in the ocean for 3,000 years before evaporating again.

2. Lightning helps the water cycle! It creates nitrogen compounds that help rainfall clean the air.

References and Further Reading

[embed]25x: Earth Science - Middle School - 25 Mini-Lessons To Introduce, Reinforce, and Highlight the… Amazon.com: 25x: Earth Science - Middle School - 25 Mini-Lessons To Introduce, Reinforce, and Highlight the Importance…www.amazon.com

[embed]Painless Earth Science book by Edward J. Denecke Jr. Buy a cheap copy of Painless Earth Science book by Edward J. Denecke Jr.. Whether you're a student or an adult looking…www.thriftbooks.com

[embed]Planet Earth used book by Anne Rooney: 9781838573782 Buy a used copy of Planet Earth book by Anne Rooney. In over four and a half billion years of existence, Planet Earth…www.betterworldbooks.com

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[embed]Client Challenge Edit descriptionwww.khanacademy.org

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[embed]What Is the Water Cycle? - NASA Science Water can be found all over Earth - in the ocean, on land, and in the atmosphere. The water cycle is the path that all…science.nasa.gov