September 16th each year is International Day for the Preservation of the Ozone Layer. The theme of the 2022 International Day for Protection of the Ozone Layer is the 35th anniversary of the Montreal Protocol: Global Cooperation protecting life on earth, reminding us that we should remember how the Montreal Protocol ended one of the greatest threats facing humanity in history - ozone layer depletion. To this end, a popular science information on ozone layer protection was released to publicize the contribution of the Montreal Protocol and promote the public's awareness of ozone layer protection knowledge.
What is the ozone layer?
Ozone layer refers to the part of the stratosphere of the atmosphere with relatively high ozone concentration, which can effectively prevent large amounts of ultraviolet rays from reaching the ground. 90% of the ozone in nature is distributed in the stratosphere about 15 to 25 kilometers away from the ground. If ozone is compressed to 1 atmosphere, its thickness is only about 3 mm, but it is this thin "3 mm ozone layer" that protects the life of the earth .
The role of the ozone layer
In a natural state, the oxygen molecules in the atmospheric stratosphere can absorb the energy of ultraviolet rays, decompose into oxygen atoms, and quickly react further with the oxygen in the atmosphere to form new ozone molecules. The ozone layer blocks a large amount of harmful ultraviolet rays to the earth, protecting human health and ecosystems.
stratosphere ozone generation reaction diagram
Origin and changes of ozone layer void
985, scientists of the British Antarctic Scientific Expedition Team, Rosef Farman, Brian Gardina and Jonathan Shanklin, discovered the Antarctic ozone hole for the first time. The so-called "empty" refers to the total ozone content of less than 220 Dobson units. Every spring, ozone in the stratosphere above Antarctic decreases dramatically due to chemical reactions. More than twenty years after the discovery of the ozone hole, the size of the ozone hole and the duration of its appearance are worrying.
Ozone layer depletion principle
20 In the 1970s, people first noticed the synthetic perchlorofluorocarbons (CFCs), commonly known as Freon, may deplete the ozone layer. Ozone-depleting substances including CFCs contain chlorine atoms. After ultraviolet irradiation in the stratosphere, the chlorine atoms are separated and reacted with ozone to form oxygen and chlorine monoxide; chlorine monoxide then reacts with free oxygen to form chlorine atoms and start the next cycle. This reaction repeats itself, and a chlorine atom can destroy thousands of ozone molecules and break the original dynamic equilibrium in the ozone layer. With the development of production, the number of ozone-depleting substances emitted into the atmosphere continues to increase, and the amount of ozone has decreased sharply.
Chemical process of destroying ozone in the stratosphere
Hazards of ozone holes
01
Human health:
damaging the cornea and lens of the eye, causing cataracts and other diseases; inducing skin cancer and other skin diseases, reducing the body's immune ability.
02
Marine organisms:
Excessive ultraviolet radiation reduces the number of plankton in shallow seas, causing the death of fish and shellfish, and damages the entire aquatic ecosystem.
03
Agricultural production:
causes the yield of beans, melons, fruits and crops.
04 Air pollution:
UV-B segment UV-B reaches the underlying atmosphere, causing the troposphere atmospheric chemical reactions to be more active, producing harmful gases and affecting air quality.
05 Social and economic:
Accelerate the aging of artificial synthetic materials and increase socio-economic costs.
Ozone-depleting substance
Ozone-depleting substance (ODS), that is, chemical substances that can cause destructive effects on the ozone layer. Ozone-depleting substances are very versatile and can be used in many aspects of daily life. Many artificial chemicals used in the production and use of refrigerators, air conditioners, electronic products, fire extinguishing equipment, tobacco, foam plastics, hair spray and insecticides can destroy the ozone layer and are ozone-depleting substances.
In daily life, how do individuals join global actions to protect the ozone layer?
The success of the Montreal Protocol means that 99% of ozone-depleting substances are now well controlled. But old refrigerators, freezers or air conditioning equipment may still contain ozone-depleting substances produced before the control is implemented. By using refrigerators, air conditioners and other equipment responsibly, individuals can also join global actions to protect the ozone layer.
01
Use general electrical appliance related
- When purchasing new equipment, look for products marked "ozone-friendly", "HCFC-free" or "energy-saving" tags.
- regularly repairs old equipment (not including fluorine-free equipment) because their failures can cause to leak into the atmosphere. When the equipment needs maintenance, please find a trained, qualified and certified organization to ensure that the equipment is properly repaired, and ozone-depleting substance is recycled and disposed of.
- Suitable insulation of walls, doors and windows to improve energy efficiency and extend the service life of the equipment.
- Regularly check for leaks in the air conditioners and refrigerators used in cars and homes. Where possible, leaked equipment should be repaired before refilling.
02
Related
- When purchasing new appliances such as refrigerators or freezers, look for products marked "ozone-friendly" or "HCFC-free" or with energy efficiency tags.
- When installing a refrigerator or freezer, make the air easy to circulate behind. Do not place the freezer next to the oven or dishwasher.
- When using a refrigerator or freezer, set the thermostat of the refrigerator or freezer at the appropriate temperature to avoid too low temperature; regularly clean the condenser behind the refrigerator and regularly deiced the freezer; only put necessary things into the refrigerator or freezer. When dealing with an old refrigerator or old freezer, send it to a qualified and certified agency to remove and recycle the refrigerant contained in the refrigerator or freezer before other parts are recycled.
03
Use air conditioner related
- When purchasing a new air conditioner, choose the air conditioner of the appropriate size.
- Try to install the air conditioner condenser in the shade outside and clean the condenser and evaporator regularly.
- Try to keep the room cool through ventilation at night, and do not use air conditioning if possible; if air conditioning is really needed to cool at night, adjust to the appropriate temperature.
- Using a fan reduces the need for additional cooling.
- After driving for a few minutes, turn on the car air conditioner.
04 Actively participate in the promotion and promotion activities of eliminating Promotion and promotion activities of
05
Report illegal production, use and import and export Ozone depleting substance Activity of
