The Earth has its own atmosphere primarily due to the force of gravity. Gravity causes gases and other particles to be pulled towards the Earth, creating a layer of gases known as the atmosphere. This atmosphere is essential for life on Earth as it provides us with the air we breathe and protects us from harmful radiation from the sun.

Option 1 - Winds: While winds are a part of the Earth`s atmosphere, they are not the reason why the Earth has an atmosphere. Winds are caused by differences in air pressure and the rotation of the Earth.

Option 2 - Clouds: Similarly, clouds are a part of the atmosphere but are not the reason for its existence. Clouds form when water vapor condenses into tiny water droplets or ice crystals.

Option 4 - Rotation of the Earth: The rotation of the Earth affects the distribution of air masses and the formation of weather patterns, but it is not the reason why the Earth has an atmosphere.

Overall, gravity is the primary factor responsible for the Earth having its own atmosphere.