Clouds owe their existence to the presence of atmospheric water vapor.

Here's why:

* Water vapor is the invisible gas form of water. It exists in the air, even when we don't see clouds.

* As warm, moist air rises, it cools. This cooling causes the water vapor to condense into tiny water droplets or ice crystals.

* These tiny droplets or crystals are what we see as clouds. They are light and buoyant enough to float in the air.

So, without water vapor in the atmosphere, there would be no clouds!