The Earth's atmosphere is our primary shield against harmful ultraviolet (UV) radiation from the sun. Specifically, a layer called the ozone layer, found in the stratosphere, is responsible for filtering out most of the harmful UV radiation.

Here's how it works:

* Ozone molecules (O3) absorb UV radiation, breaking apart into oxygen molecules (O2) and single oxygen atoms (O).

* This process converts the harmful UV radiation into heat, protecting life on Earth.

Other factors also contribute to protecting life from UV radiation:

* Clouds: Reflect a significant portion of UV radiation back into space.

* The Earth's magnetic field: Deflects most of the harmful charged particles from the sun, preventing them from reaching the atmosphere.

* Elevation: Higher altitudes have less atmospheric protection, leading to increased UV exposure.

While the ozone layer is a vital protector, it is facing threats from human activities like pollution. The depletion of the ozone layer can lead to increased UV radiation reaching the surface, with potential negative impacts on human health and ecosystems.