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Look up at the sky — what exactly do we mean by the “air” around us?
![3.1 What Is the Atmosphere? - Atmosphere and Climate - [Teachoo] - Concepts](https://cdn.teachoo.com/24fe13a5-a6ca-4513-9bb7-c1f4e7ad08ac/clouds-sunshine-and-breeze-are-all-results-of-the-atmosphere-around-us..jpg)
Atmosphere
Atmo-
vapour / air
-sphere
envelope around Earth
↓
The blanket of air surrounding Earth, held by gravity, supporting life and weather.
- The atmosphere is a blanket of air surrounding the Earth.
- It is a mixture of gases in different proportions.
- It is vital for the survival of all living beings.
- It shields us from harmful solar radiation .
- It regulates the Earth’s temperature .
- It is a key part of Earth’s weather and climate systems.
Why does this air stay around the Earth instead of floating away into space?
Gravity
Grav-
heavy / weight
-ity
state or force idea
↓
The force that pulls air and objects towards Earth, helping keep the atmosphere in place.
- Gravity is a fundamental physical force of attraction.
- It acts between any objects that have mass .
- The Sun and the Earth attract each other this way.
- The Earth’s mass also pulls objects close to its surface .
- This pull on nearby objects is called Earth’s gravity .
- It is what holds the atmosphere from escaping into space.
Definition — Atmosphere
A blanket of air surrounding the Earth.
It is a mixture of gases held in place by gravity.
It is vital for the survival of living beings.
It is a mixture of gases held in place by gravity.
It is vital for the survival of living beings.
Now that we know what the atmosphere is, what does it actually do for us?
Why does the atmosphere matter?
Atmosphere's Roles
For life and for climate
1. Keeps Us Alive
Gives oxygen, absorbs CO2
Ozone blocks UV radiation
Example:
Breathable air, ozone layer
2. Shapes the Climate
Traps heat, keeps warmth in
Creates weather and climate
Example:
Temperature, wind, rainfall
- The atmosphere supports life with oxygen and carbon dioxide.
- It protects life from harmful ultraviolet radiation.
- It regulates temperature by trapping some solar energy.
- It stops all of the Sun’s energy from escaping back into space.
- It is a key component of Earth’s weather and climate systems.
- It influences temperature, humidity and air pressure.
What would actually happen if the Earth had no atmosphere at all?
What if there was no atmosphere?
No blanket of gases
There would be no breathable air and no clouds or rain.
↓
No ozone shield
Harmful ultraviolet radiation would reach the Earth directly.
↓
No trapped heat
Temperatures would swing between extreme heat and cold.
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Life as we know it could not survive on Earth.
- There would be no breathable air , no clouds, no rain.
- There would be no shield against ultraviolet radiation.
- Temperatures would swing between extreme heat and cold .
- Life as we know it could not survive .
🤔 THINK ABOUT IT
Can you imagine what would happen if there were no atmosphere? Discuss your thoughts with your friends and teachers.
📝 What Have We Learned
- The atmosphere is a blanket of gases around the Earth.
- Gravity holds this blanket in place.
- It supports life, protects us, and regulates temperature.
- It creates all of Earth’s weather and climate.
- Without it, life on Earth could not survive.
