Not just air
Air is mostly gas, but it also holds lots of tiny particles. These particles, like dust and pollen, are called aerosols and are picked up when the wind blows. But the air can also carry soot, smoke, and other particles from car exhaust and power plants. These are major contributors to air pollution.
Air is Life!
People, other animals, plants…they all need to breathe! Respiration consists in taking in oxygen from the air and expelling carbon dioxide (or the opposite in the case of plants!). Through this process all animals and plants get the energy they need to grow and live life!
Air has life!
There’s life on…air! We aspect to see living organisms in soil or in water, but they can also be found hanging out in the air. These are called bio-aerosols and are microbial organisms that can travel through the air, via breeze or just a sneeze!
Air and the Water-Cycle
Air helps water move between its states (solid, liquid, gaseous) in a process called the water cycle.
When heated by the sun, water evaporates into the air and becomes water vapor. As temperatures drop, water vapor condenses, forming clouds. Clouds return water to the ground in the form of rain, sleet or snow and they move, transporting water far from where it originated.
Air can be heavy!
As light as air…that is not always the case! Actually, air pressure pushes down on Earth’s surface.
At the sea level, air pressure is quite high…you can feel the whole atmosphere pushing down. On the other side, up on the mountains the air pressure is low because there is less atmosphere pushing down on you. Do your ears pop when you’re taking off in an airplane? That is caused by the difference in air pressure!
Air protects us
Having an atmosphere filled with air is why Earth is not too hot or too cold, allowing life to spread.
Earth’s ozone layer helps reduce the amount of harmful ultraviolet radiation from the Sun and our atmosphere protects us from X-rays and cosmic rays. Air also reduces the possibility that meteorites and asteroids could reach our cities.
Air means sound…
Your favourite song? You can hear that just because of air. People can hear sound only because air carries sound waves from one point to another.
…and blue skies
That’s right! The sky appears blue because air molecules cause violet and blue wavelengths of sunlight to scatter. Are you worried about grey? With no air, the sky would always be black!