At the top of the stratosphere of the Earth at an altitude of 20 km to 50, it is a layer of ozone - triatomic oxygen.
Under the influence of ultraviolet radiation normal oxygen molecule (O2) adds another atom, and the result is a molecule of ozone (O3).
The protective layer of the planet
The more ozone in the atmosphere, thegreater amount of ultraviolet radiation it is able to absorb. Without the protection of the radiation is too intense and can cause significant damage to all living creatures and thermal burns, and human can lead to skin cancer.
If the whole atmosphere ozone evenly distributed over an area the size of 45 square kilometers, its thickness will be only 0.3 cm.
The harm of ozone on the surface of the planet
When the exhaust gases and industrial emissionsreact with the rays of the sun, as a result of photochemical reactions of ground-level ozone is formed. Usually, this phenomenon occurs in metropolitan areas and large cities. Inhalation of the dangerous ozone. As this gas is a strong oxidant, it can easily destroy the living tissues. They suffer not only people, but also plants.
Ozone layer depletion
In the 70 years it has been observed during studiesthat Freon gas, which is used in air conditioners, refrigerators and spray cans, with great speed destroys ozone. Climbing up into the upper layer of the atmosphere, CFCs release chlorine, which decomposes ozone to normal and atomic oxygen. In place of these interactions formed the ozone hole.
From what protects the ozone layer
Ozone holes are ubiquitous, but withchanging many factors they overlap from neighboring ozone atmosphere. Those, in turn, become even thinner. The ozone layer acts as the sole obstacle to the damaging ultraviolet radiation and radiation from the sun. Without the ozone layer human immune system would be destroyed.
According to scientists, the reduction of the ozone layer by 1% increases the likelihood of cancer by 3-6%.
Reducing the amount of ozone in the atmosphereunpredictable climate change on the planet. Since the ozone layer retains heat, which is dissipated from the surface of the Earth, as the depletion of the ozone layer climate becomes colder, the wind direction will change some. All this will lead to natural disasters.
The Montreal protocol
In 1989, the majority of the States which areUN member states have signed an agreement under which the production of ozone-depleting CFC gases and must be stopped. Scientists have calculated that after signing the agreement the ozone layer should recover fully by 2050.