Chlorofluorocarbons (CFCs), hydrochlorofluorocarbons (HCFCs) and halons
destroy the earth’s protective ozone layer
, which shields the earth from harmful ultraviolet (UV-B) rays generated from the sun. CFCs and HCFCs also warm the lower atmosphere of the earth, changing global climate.
What happens to CFCs in the upper atmosphere?
The abundance of CFC-11 decreases as the gas reaches higher altitudes, where it is broken down by
high energy solar ultraviolet radiation
. Chlorine released from this breakdown of CFC-11 and other CFCs remains in the stratosphere for several years, where it destroys many thousands of molecules of ozone.
How does CFC destroy ozone?
CFCs do not easily react with other substances. In fact, they break up only
through sunlight
, which divides their molecules, causing the release of chlorine (Cl). Once the chlorine is released, it is able to react with ozone (O3), to form chlorine monoxide (ClO) and oxygen (O2).
Why are CFCs so destructive?
CFCs can
only be destroyed by extremely energetic ultraviolet radiation
, such as is found above most of the ozone layer. … The photolysis of CFCs generates a highly reactive chlorine atom that can attack ozone or form compounds that destroy ozone.
Do CFCs pollute the air?
Pollutants can also damage the atmosphere above Earth’s surface
. A well-known example of this damage is that caused by chlorofluorocarbons (CFCs). CFCs were used for many years as coolant in refrigerators and as cleaning agents. … Air pollutants can travel surprisingly far and fast.
Are CFCs still used?
Production of
CFCs ceased in 1995
. HCFC production will cease in 2020 (HCFC-22) or 2030 (HCFC-123). This means that although equipment that uses these refrigerants may operate just fine for 20 or 30 years, new or recycled refrigerant to service it may not be available. Don’t buy equipment that uses CFC refrigerants.
How are we destroying the ozone layer?
Ozone depletion occurs when
chlorofluorocarbons (CFCs) and halons
—gases formerly found in aerosol spray cans and refrigerants—are released into the atmosphere (see details below). … CFCs and halons cause chemical reactions that break down ozone molecules, reducing ozone’s ultraviolet radiation-absorbing capacity.
Why do CFCs stay in the atmosphere for so long?
CFCs reach the stratosphere because
the Earth’s atmosphere is always in motion and mixes the chemicals added into it
. … Gases such as CFCs that do not dissolve in water and that are relatively unreactive in the lower atmosphere are mixed relatively quickly and therefore reach the stratosphere regardless of their weight.
Is ultraviolet A ray?
Ultraviolet (UV) is
a form of electromagnetic radiation
with wavelength from 10 nm (with a corresponding frequency around 30 PHz) to 400 nm (750 THz), shorter than that of visible light, but longer than X-rays. … Short-wave ultraviolet light damages DNA and sterilizes surfaces with which it comes into contact.
How can we reduce CFCs?
Buy air-conditioning and refrigeration equipment that do not use HCFCs as refrigerant. Buy aerosol products that do not use HCFCs or CFCs as propellants.
Conduct regular inspection and maintenance of air-conditioning and refrigeration appliances
to prevent and minimize refrigerant leakage.
What gas makes up 21%?
Earth’s atmosphere is composed of about 78 percent nitrogen, 21 percent
oxygen
, 0.9 percent argon, and 0.1 percent other gases.
How long do CFCs last?
The environmental concern for CFCs follows from their long atmospheric lifetime
(55 years for CFC-11 and 140 years for CFC-12, CCl
2
F
2
)
9
which limits our ability to reduce their abundance in the atmosphere and associated future ozone loss.
Are CFCs toxic to breathe?
Inhaling CFCs
Inhalation of CFCs can also disturb the heart rhythm, which can lead to death. Exposure to large amount of CFCs could
potentially cause asphyxiation
, according to the Centers for Disease Control and Prevention.
What are the most powerful gases on Earth?
You read right:
SF6
is the most potent greenhouse gas in existence with a global warming potential of 23,900 times the baseline of CO
2
. It means that one tonne of SF6 in the atmosphere equals 23,900 tonnes of CO
2
.
What is the most important greenhouse gas on Earth?
Carbon dioxide (CO
2
)
is the primary greenhouse gas emitted through human activities. In 2019, CO
2
accounted for about 80 percent of all U.S. greenhouse gas emissions from human activities.
What is the biggest single cause of air pollution?
In terms of overall range and extents of impacts, however, it is my opinion that
burning of fossil fuels (coal, gasoline, etc..)
is the single largest source of air pollutants. These fuels cause smog, acid rain, soot and particulates increases, greenhouse gas emissions, and dispersal of some heavy metal contaminants.
