Stratospheric ozone is formed
naturally by chemical reactions involving solar ultraviolet
radiation (sunlight) and oxygen molecules, which make up
21% of the atmosphere. In the first step, solar ultraviolet
radiation breaks apart one oxygen molecule (O2) to produce
two oxygen atoms (2 O). In the second step,
each of these highly reactive atoms combines with an oxygen
molecule to produce an ozone molecule (O3). These reactions
occur continually whenever solar ultraviolet radiation is present
in the stratosphere. As a result, the largest ozone production
occurs in the tropical stratosphere.
It corresponds with the rapid growth and development of the human species over the planet and current period of warm period and it's stated around 11,650 cal years ago before the present.
The specification of the species is known to have been taken place about 350,000 years ago, in the spit for the Netherlands in about 500,000 to 800,000 years ago. And earliest descendants were the H. Erectus some 1.8 million years ago.
Formulation of the neolithic culture of agriculture that was one of the primary forms of the early occupation on the planet started on the 0.0117 million years ago.
Thus about 87% of the planet has nee occupied b the human since there geologic period.
