Q1.
Why is the ozone layer so important?
Answer
Because it is the only thing that absorbs the Sun's short-wavelength ultraviolet radiation before it reaches the ground. Without it, UV would damage the eyes, skin and DNA of living organisms and would break down whole ecosystems.
Ozone sits in the stratosphere (12 – 50 km)
UV wavelength range = 100 nm to 400 nm, where 1 nm = 10–9 m
Shorter wavelength → higher energy → more damage to living tissue
Ozone absorbs this UV → the energy warms the stratosphere instead of harming life
UV wavelength range = 100 nm to 400 nm, where 1 nm = 10–9 m
Shorter wavelength → higher energy → more damage to living tissue
Ozone absorbs this UV → the energy warms the stratosphere instead of harming life
The story the box tells, and why it matters:
- How the layer is lost. Ozone is being formed and destroyed all the time. Trouble begins only when "ozone molecules are destroyed faster than they are naturally formed" — then the layer thins.
- What caused it. Human-made chlorofluorocarbons (CFCs), used in refrigerators and aerosols, drifted up to the stratosphere and destroyed ozone. The severe thinning over Antarctica became known as the ozone hole.
- What was done. The Montreal Protocol, a global agreement, cut the use of CFCs — and the layer is now slowly recovering.
Do not confuse the two ozones. Ozone high up, in the stratosphere, is protective — it blocks UV. Ozone at ground level, formed when vehicle exhaust reacts with sunlight, is a pollutant that is "harmful for health". Same molecule, opposite verdict, decided entirely by where it is.