What is ozone hole?

Options

A. Hole in the ozone layer
B. Thinning of ozone layer in troposphere
C. Formation of ozone layer
D. Reduction in ozone thickness in stratosphere

Answer

### Step-by-Step Solution

1. **Definition of Ozone Hole**: The ozone hole refers to a significant reduction in the concentration of ozone (O₃) in a specific region of the stratosphere.

2. **Location**: The ozone hole is primarily observed over Antarctica, particularly during the spring months (September to November) when the depletion is most pronounced.

3. **Cause of Ozone Depletion**: The depletion of ozone is mainly caused by human-made chemicals, particularly chlorofluorocarbons (CFCs) and halons. These substances release chlorine and bromine when they are broken down by ultraviolet (UV) radiation, which then catalyze the destruction of ozone molecules.

4. **Consequences**: The thinning of the ozone layer allows increased levels of harmful ultraviolet radiation from the sun to reach the Earth's surface, which can lead to increased skin cancer rates, cataracts, and other environmental impacts.

5. **Correct Option**: Among the given options, the correct description of the ozone hole is "reduction in ozone thickness in the stratosphere."