The destruction of the ozone layer is provoked mainly by the use of synthetic gases CFC (chlorine-fluor-carbon). Its action on ozone only generates the same reaction that occurs in the stratosphere, with ozone and oxygen, that is artificial, modifying the normal cycle of regeneration of the layer :
O3 + Cl + u.v.®Cl O + O2
Cl O + O ®O2 + Cl
O3 + O + u.v.®2 O2
As if it can observe, the chlorine that came of the CFC acts as a catakyser, not being consumed in the process and thus, the scientists say that its action in the atmosphere can continue per 50 years. Or either, the ozone layer's role goes to continue magnifying for a time.
It is necessary, then, does not launch more CFC in the atmosphere. Up to 1987, when the Protocol of Montreal was signed, many industries used CFC as aerosol propellant, insulators in devices of refrigeration (refrigerator, to freezer, conditional air) and in the production of plastic materials, as foam and packings. When the paper of the CFC in the ozone layer's destruction was uncovered, 155 countries had signed an agreement to substitute it up to 1996, other countries if they had compromised to make it up to 2010, with the financial and technological aid that the Protocol of Montreal foresaw. The CFCs are being substituted for another gas, the HCFC, that attacks little the ozone layer.
Today, he ozone hole has more than 28.3 million kilometers squared - three times the size Brazil. It is at 30 km of the terrestrial surface, in the stratosphere, on the South Pole. According to scientists, the location if must to the fact of being the region whit lesser temperatures of the Land and litle air refreshing. The reaction of in addition ozone is sped up by these factors, therefore it is exothermic.
