Question

what is ozone discuss its role in protecting the life on earth which human activities are depleting ozone layer

Answer 1

The ozone layer acts as a filter for the shorter wavelength and highly hazardous ultraviolet radiation (UVR) from the sun, protecting life on Earth from its potentially harmful effects. When the sky is clear, there is an inverse relationship between stratospheric ozone and solar UVR measured at the Earth’s surface. That is,the lower the ozone levels, the higher the solar UVR.

The level of UVR from the sun measured at the Earth’s surface varies linearly with latitude. There are higher UVR levels nearer the equator and lower UVR nearer the poles (see Figure 1).

Australia has high levels of solar UVR, due mainly to its geographical position. We have capital cities at latitudes ranging from 12°30’S (Darwin) close to the equator down to 42°52’S (Hobart). For comparison with some Northern Hemisphere locations, the south of France is 43°N and London is 51°32’N, while Melbourne at 37°46’S is as far from the equator as the coast of North Africa (37°16’N).

The southern hemisphere generally has higher levels of solar UVR than the northern hemisphere, because the Earth is approximately 1.7% closer to the sun in January (summer) than at the equinox and 1.7% further away in July (northern hemisphere summer). The intensity of solar UVR is proportional to the square of the distance, so this means solar UVR levels are already 3.4% higher in the southern Hemisphere than at equinox and 3.4% lower for an equivalent location in the northern hemisphere. However as the atmosphere in the southern hemisphere is cleaner than that in the northern and transmits UVR more readily, these differences are even larger for similar latitudes, approaching ~15%.

Answer 2

Ozone is a protecting layer above our Earth's stratosphere. It acts like a blanket. It protects us from harmful Ultra Violet Rays (UV rays) which came from sun. They are very harmful for our skin and eyes. Because of excessive use of Chloro Flouro Carbon (CFCs) ozone depletion happens. CFCs is produced by vehicles, ACs and refrigerators.
We can't close this depletion but we can reduce it by minimize the use of refrigerator, ACs and vehicles.