Ozone Layer
The atmosphere is divided into layers of different physiochemical characteristics.
The ozone layer is located in the stratosphere.
Ozone is a gas composed by three atoms of oxygen (O3) Its main function is to filter ultraviolet rays (UV) from the sun.
There are 2 kinds of Ozone
STRATOSPHERIC OZONE
It's in the stratosphere 50km away from the Earth's surface.
It's an essential gas that protects the Earth from harmful ultraviolet rays from the sun.
The use of ODS (substances that deplete the ozone layer) produces the atmospheric ozone depletion.
The hole in the ozone layer allows entry of most UV rays and involves a cooling of the atmosphere's upper layer.
LESS STRATOSPHERIC OZONE.
Less infrared radiation retention
COOLER CLIMATE
TROPOSPHERIC OZONE
In the troposphere 10 km away from the Earth's surface.
This gas is harmful to health and contributes to the greenhouse effect.
Human pollution contributes to increased tropospheric ozone.
Tropospheric ozone retains infrared heating and increases the planet heating.
MORE STRATOSPHERIC OZONE
More radiation retention
WARMER CLIMATE
What are ultraviolet rays?
It's sun energy that reaches the Earth, classified into three types according to their wavelength.
UVA
Wavelength between 320 and 400 nm.
It penetrates the atmosphere. Not harmful in controlled sun exposure.
UVB
Wavelength between 280 and 400 nm.
The ozone layer absorbs most of these rays. Harmful to health.
UVC
Wavelength between 200 and 280 nm.
The ozone layer absorbs them. Very harmful to health.
Ultraviolet radiation's harmful effects on health.
For decades, the concentration of this gas in the atmosphere has been reduced, considerably affecting the ozone layer and creating "holes".
Skin burns
Cancer
DNA molecules destruction
and reduced growth of plants and crops.

The emission of chlorofluorocarbons (CFCs) into the atmosphere causes the released chlorine atoms (Cl) to destroy the ozone.

WHAT ARE CFCS?

Artificial chemical gases hard to degrade, which have a long-term presence in the atmosphere (50-100 years)

WHERE ARE CFCS FOUND?
 
Cleaning products
 
Aerosol sprays
 
Refrigeration equipment
 
Agricultural spraying
DID YOU KNOW...?
The main ozone depletion lies over Antarctica although there are holes in other areas, including the Arctic?
International agreements for the protection of the ozone layer
1976
USA National Academy of Sciences
It provides scientific evidence on ozone depletion.
1985
Vienna Convention for the Protection of the Ozone Layer.
Signed by 20 countries to research and control ozone-depleting substances.
1987
Montreal Protocol
Agreements signed by 43 countries to maintain production levels of CFCs from 1986 and reduce them by 50% in 1999, which subsequently would be brought forward to 1996.
2015
30th Anniversary of the Vienna Convention
For the Protection of the Ozone Layer.
September 16th marks the International Day for the Preservation of the Ozone Layer in commemoration of the signing of the Montreal Protocol.