The crisis of the Earth's shield: the cause of the destruction of the ozone layer

The ozone layer is an important component of the earth's atmosphere. It is located in the upper part of the stratosphere, which can filter out harmful rays from the sun and protect organisms on the earth from various radiation damage. However, due to human activities, a big hole was opened in this shield of the earth, and the ecological balance formed for thousands of years was thus broken. So, what exactly caused the breach of this important protective shield? Let us continue to look down.

Where is the ozone layer and how is it formed?

The ozone layer is located inStratosphereInside, about 15 to 35 kilometers above the surface. The stratosphere is the second layer of the atmosphere, located above the troposphere (Troposphere), its upper boundary is the Stratopause (Stratopause), the lower boundary is the Tropopause (Tropopause). The troposphere is the layer closest to the Earth's surface, where most weather phenomena and atmospheric changes occur.

Ozone production follows the following reaction:

1. Oxygen molecules in the atmosphere (O₂), decomposing it into two oxygen atoms (O): O₂ + photon → 2O
2. These single oxygen atoms combine with other oxygen molecules to form ozone molecules (O₃): O + O₂ →₃
3. After the ozone molecule absorbs light energy of a specific wavelength (310-200nm), it will decompose into an oxygen molecule and an oxygen atom, and finally the oxygen atom and the ozone molecule have the opportunity to combine to form two oxygen molecules: O + O₃ → 2O₂

The mutual conversion of the three goes round and round, forming the oxygen atoms (O) and oxygen molecules (O) of the ozone layer.₂) and ozone (O₃) of the dynamic equilibrium process.

What is the function of the ozone layer?

The following are the main functions of the ozone layer:

1. Absorbs and scatters UV light: The main function of the ozone layer is to absorb and scatter ultraviolet B (UV-B) and ultraviolet C (UV-C) from the sun. These short-wavelength ultraviolet rays can cause serious harm to humans, animals, plants, and ecosystems. The ozone layer absorbs and scatters these ultraviolet rays, reducing the amount of them reaching the earth's surface and protecting life on earth from harm.
2. protect human health: Ultraviolet B rays are one of the causes of skin cancer and cataracts, and may have adverse effects on the immune system. The ozone layer reduces these health risks and protects humans from UV radiation.
3. maintain ecological balance: The ozone layer helps maintain the stability of the ecosystem, protects plants and animals from ultraviolet rays, and ensures ecological diversity and species survival.
4. adjust the temperature of the atmosphere: The ozone layer absorbs ultraviolet energy and releases thermal energy, which helps regulate the temperature of the stratosphere, which has an important impact on the heat balance of the atmosphere and climate regulation.

What would the world be like without the ozone layer?

Losing the protection of the ozone layer would result in more radiation exposure for life on Earth, which could cause:

1. destroy biomolecules: High energy radiation can damage biomolecules, especially DNA molecules. The existence of the ozone layer can block most of the ultraviolet rays B and C. If the protection of the ozone layer is lost, more ultraviolet rays will enter the earth's surface, which may cause damage to biomolecules and affect the survival and function of organisms.
2. Increased incidence of skin cancer and cataracts: Short-wavelength ultraviolet rays are one of the main causes of skin cancer and cataracts. Without the protection of the ozone layer, more short-wavelength UV rays would reach the surface unimpeded, raising the risk of skin cancer and cataracts.
3. suppressed immune system: Ultraviolet light may also have adverse effects on the immune system, which will make people less resistant to pathogens and more likely to get sick.
4. destroy the natural ecological balance: Some species may not be able to adapt to more ultraviolet rays, which may lead to species extinction or migration, affecting the stability of the entire ecological chain.
5. Plant growth retardation, crop yield reduction: Short-wavelength ultraviolet rays can inhibit the growth and development of plants and affect the yield and quality of crops.
6. Climate change, causing the greenhouse effect, causing sea level rise: The ozone layer has the function of regulating the balance of the atmosphere, so the destruction of the ozone layer may cause climate change, which has a wide impact on the global climate and the earth's ecosystem.
7. Produce photochemical smog, causing air pollution: Reactions between ultraviolet light and other chemicals in the ozone layer can produce photochemical smog, an air pollutant that is harmful to both humans and the environment.
8. Accelerated aging of rubber products and plastics: Ultraviolet rays can also cause damage to materials such as plastics and rubber, accelerating their aging and damage.

Surprise! What is the reason for the destruction of the ozone layer?

The main reason for the destruction of the ozone layer is caused by chemical substances released by human activities, especiallyChlorofluorocarbons (CFCs),Hydrobromocarbons (HBFCs),Hydrochlorofluorocarbons (HCFCs)andHalonsand other substances. These chemicals are calledOzone-depleting substances (ODS), They are mainly used in industry, refrigeration equipment, air conditioners and aerosols, etc. When these substances are released into the atmosphere, they gradually rise to the stratosphere and then enter the range of the ozone layer.

In the ozone layer, these ODS will be affected by sunlight, especially under the action of ultraviolet rays, ODS will undergo photolysis reaction and releaseChlorine atom (Cl)andFluorine atom (F). These chlorine and fluorine atoms react with the ozone molecules, causing the destruction of the ozone molecules. And these ODS substances will remain in the atmosphere for a long time, and when they dissipate and decompose, they may have destroyed thousands of ozone molecules. The worst ozone depletion has occurred in the Antarctic and Arctic regions, especially in theAntarctic ozone hole. The reason for the formation of this hole is that the destructive effect of ODS is more severe due to the special geographical environment and extreme low temperature.

Since the use of ODS in the middle of the 20th century, scholars from various countries have proved that the destruction of the ozone layer is closely related to these ODS substances through a large amount of research and analysis. In order to slow down the destruction of the ozone layer, countries signed the"Montreal Protocol", the protocol aims to limit and phase out the use of ODS products to avoid continued damage and deterioration of the ozone layer. Driven by this international agreement, many countries have taken various measures to reduce the use of ODS substances and gradually repair the hole in the ozone layer.

How to protect our ozone layer?

Protecting the ozone layer is a shared global responsibility. Here are some steps you can take to protect the ozone layer:

1. Restriction and Eliminationozone depleting substances(ODS) usage: The most direct way is to limit and phase out the use of chemicals that cause ozone depletion, such as CFCs, HCFCs and halons. Through international agreements and regulations, the production, import and use of these substances are restricted, prompting the industry to switch to more environmentally friendly alternatives.
2. Promote research and development of green technologies and alternatives: Develop greener alternatives to ozone-depleting chemicals.
3. raise public awareness: Raise public awareness of ozone layer protection and encourage people to reduce the use of harmful substances.
4. Support research and monitoring: Continue scientific research on the ozone layer, monitor the status and changes of the ozone layer, and formulate corresponding protection measures.
5. Reduce Greenhouse Gas Emissions: Emissions of greenhouse gases may also have an impact on the ozone layer, exacerbating the risk of ozone layer depletion. Therefore, reducing the emission of greenhouse gases, especially carbon dioxide and methane, is very important for protecting the ozone layer and mitigating climate change.
6. Support international agreements and policies: Support international environmental agreements, such as"Montreal Protocol"etc., to promote international cooperation, formulate and implement stronger policies and measures to ensure the effective protection of the ozone layer.

Restoration of the ozone layer

Signed since 1987"Montreal Protocol"Since then, the international community has worked together to carry out a number of measures aimed at the destruction of the ozone layer. These efforts have yielded some results, and progress in the recovery of the ozone layer is gradually becoming apparent:

1. Increased thickness of the ozone layer: Since the 1990s, the thickness of the ozone layer has increased as the use of ozone-destroying substances such as CFCs has decreased. According to scientific research, the thickness of the ozone layer is increasing by about 1% to 3% every year, which indicates that the recovery process of the ozone layer is underway.
2. Shrinking of the Antarctic ozone hole: Antarctica is the most severely damaged place in the global ozone layer. Due to international cooperation and the elimination of ODS, the size of the Antarctic ozone hole has gradually shrunk since 2000, and NASA also announced in 2019 that the Antarctic ozone hole is the smallest since its discovery in 1982.
3. Reduction in the use of ODS products: Many countries have reduced the production and use of ODS products, which has a positive impact on the recovery of the ozone layer.
4. raising public awareness: The publicity and education on the protection of the ozone layer has achieved great results, which has made the public have a deeper understanding of the importance of the ozone layer, and more and more people have begun to pay attention to environmental protection and actively participate in reducing the damage to the ozone layer.

Holidays for the Ozone Layer – International Day for the Preservation of the Ozone Layer

International Day for the Preservation of the Ozone Layer, also known as "World Ozone Layer Protection Day", is an international day of commemoration that is held on September 16 every year. This special day is to remind countries and the public of the world to pay attention, advocacy and action to jointly protect the Earth's ozone layer, and to celebrate global efforts and achievements in this regard.

The International Day for the Preservation of the Ozone Layer was officially established by the United Nations in 1994 and is celebrated on September 16 every year. This date was chosen because on the same day in 1987, 16 September, the international community formally signed"Montreal Protocol", a protocol aimed at limiting and phasing out chemicals that damage the ozone layer.

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References

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2. ozone layer hole - Wikipedia

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4. Neha Jain, A Literature Review on Ozone Layer Effect.IJARIIE-ISSN(O)-2395-4396

5. The pictures in the article are all from the CC0 free gallery.