What does Ozone Damage look like?
When exposed to high levels of ozone, many plants show damage on their leaves. Older leaves have the most damage. Plants with ozone damage have very fine colored spots on the upper surfaces of their leaves, and some leaves also turn yellow.
Why does NASA have an Ozone Garden?
NASA's work involves a great deal of research in the service of society on our own planet, including studies of air quality. The Ozone Garden helps to educate people about ozone in our atmosphere. NASA's vision is to improve life here, to extend life to there, and to find life beyond. Ozone research contributes to the NASA vision by using satellite missions, such as Aura, to monitor the health of Earth's atmosphere.
What is Ozone?
Ninety percent of the ozone in the atmosphere sits in the
stratosphere, the layer of atmosphere between about 10 and 50 kilometers
altitude. Ozone in the stratosphere is created when the kind of oxygen
we breathe - O2 - is split apart by sunlight into single oxygen atoms.
Single oxygen atoms can re-join to make O2, or they can join with O2
molecules to make ozone (O3)
Where is Ozone?
Ozone is found in two places in the Earth's atmosphere. Ozone in the
Earth's upper atmosphere (stratosphere) protects life from harmful
ultraviolet (UV) rays from the sun. High concentrations of ozone found
in the Earth's lower atmosphere (troposphere) are hazardous to life.
How is Tropospheric Ozone Created?
Ozone in the lower atmosphere (troposphere) is created through a
series of reactions involving man-made chemical species such as Nitrogen
oxides (NOx) and volatile organic compounds (VOCs). Chemical species
that contribute to ground level ozone.
How does it affect me?
In high concentrations, ground level ozone is toxic to human tissue.
When ozone levels get too high, the EPA issues "Code Red" days, on
which humans should limit their time outdoors.
Look ahead in the world of contusion and chaos, we often feel the
need to step into a realm of peace and tranquility. The 20th century
since 1950 may rightly be called The Era of Development’ due to rapid
industrialization. Urbanization and colonization Development became
synonymous with growth. The exploitation of colonies and extension of
trade cmpiresptoyed an Important role Intt. As I consequence, today the
earth has become the victim of onslaught of a materialistic
civilization.
ill Effects Of Pollution
The ill effects of industrial pollution and deforestation are now apparent Carbon monoxide and other harmful gases have spread in the atmosphere.
Forests have disappeared and lakes have dried up. The sight of open, clear sky has become a distant dream. Trees are also disappearing day by day. Due to this, many species have become extinct. Thus it can be rightly said: Pollution Pollution Every where Not even a single fight left to stare Due to this, ecological balance has been facing a grave threat. This problem has become 10 complex and universal that no country can succeed in tackling it alone. Inspite of the dedicated efforts of the developing and developed countries there exists a wide gap between awareness and action towards environment protection.
Forests have disappeared and lakes have dried up. The sight of open, clear sky has become a distant dream. Trees are also disappearing day by day. Due to this, many species have become extinct. Thus it can be rightly said: Pollution Pollution Every where Not even a single fight left to stare Due to this, ecological balance has been facing a grave threat. This problem has become 10 complex and universal that no country can succeed in tackling it alone. Inspite of the dedicated efforts of the developing and developed countries there exists a wide gap between awareness and action towards environment protection.
What To Do to save earth from Pollution
At this critical juncture/ the world has to act as a Global
Community. Unless our development plans are guided by our environment
needs, we will tail to achieve sustainable progress. The governments of
respective countries alone cannot be blamed. People should also
co-operate with them ,so the problem of pollution.?
REPAIRING THE OZONE LAYER
Scientists have found "holes" in the ozone layer high above the Earth. The 1990 Clean Air Act has provisions for fixing the holes, but repairs will take a long time. Ozone in the stratosphere, a layer of the atmosphere nine to 31 miles above the Earth, serves as a protective shield, filtering out harmful sun rays, including a type of sunlight called ultraviolet B. Exposure to ultraviolet B has been linked to
development of cataracts (eye damage) and skin cancer. In the mid-1970s, scientists suggested that chlorofluorocarbons (CFCs) could destroy stratospheric ozone. CFCs were widely used then as aerosol propellants in consumer products such as hair sprays and deodorants, and for may uses in industry. Because of concern about the possible effects of CFCs on the ozone layer, in 1978 the U.S. government banned CFCs as propellants in aerosol cans.
Since the aerosol ban, scientists have been measuring the ozone layer. A few years ago, and ozone hole was found above Antarctica, including the area of the South Pole. This hole, which has been appearing each year during the Antarctic winter (our summer), is bigger than the continental United States. More recently, ozone thinning has been found in the stratosphere above the northern half of the United States; the hole extends over Canada and up into the Arctic regions (the area of the North Pole). The hole was first found only in winter and spring, but more recently has continued into summer. Between 1978 and 1991, there was a 4-5 percent loss of ozone in the stratosphere over the United States; this is a significant loss of ozone. Ozone holes have also been found over northern Europe.
What could a thinned-out ozone layer do to people's lives? There could be more skin cancers and cataracts. Scientists are looking into possible harm to agriculture, and there is already some evidence of damage to plant life in Antarctic seas. Evidence that the ozone layer is dwindling let 93 nations, including the major industrialized nations, to agree to cooperate in reducing production and use of chemicals that destroy the ozone layer. As it became clear the ozone layer was thinning even more quickly than first thought, the agreement was revised to speed up the phase-out of ozone-destroying chemicals. Unfortunately, it will be a long time before we see the ozone layer repaired. Because of the ozone-destroying chemicals already in the stratosphere and those that will arrive within the next few years, ozone destruction will likely continue for another twenty years.
The 1990 Clean Air Act sets a schedule for ending production of chemicals that destroy stratospheric ozone. Chemicals that cause the most damage will be phased out first. The phase-out schedule can be speeded up if an earlier end to production of ozone-destroying substances is needed to protect the ozone layer. The table on this page on Ozone-destroying chemicals includes "speeded-up" phase-out dates which were proposed by EPA in early 1993. CFCs, Halons, HCFCs (hydrochlorofluorocarbons) and other ozone-destroying chemicals were listed by Congress in the 1990 Clean Air Act and must be phased out. The Act also lets EPA list other chemicals that destroy ozone. EPA issues allowances to control manufacture of chemicals being phased out. Companies can also sell unused allowances to companies still making the chemicals or can use the allowances, within certain limits, to make a different, less ozone-destroying chemical on the phase-out list. In addition to requiring the phasing out of production of ozone-destroying chemicals, the Clean Air Act takes other types to protect the ozone layer. The law requires recycling of CFCs and labeling of products containing ozone-destroying chemicals. The 1990 Clean Air Act also encourages the development of "ozone-friendly" substitutes for ozone-destroying chemicals.
CFCs from car air conditioners are the biggest single source of ozone-destroying chemicals. By the end of 1993, all car air conditioner systems must be serviced using equipment that recycles CFCs and prevents their release into the air. Larger auto service shops were required to start using this special equipment in January 1992. Only specially-trained and certified repair persons will be allowed to buy the small cans of CFCs used in servicing auto air conditioners. As CFCs and related chemicals are phased out, appliances and industrial processes that now use the chemicals will change. For example, industrial and home refrigerators will be changed to use refrigerants that don't destroy ozone. In the meantime, refrigerator servicing and disposal will have to be done in ways that don't destroy ozone. In the meantime, refrigerator servicing and disposal will have to be done in ways that don't release CFCs. Methyl chloroform, also called
Scientists have found "holes" in the ozone layer high above the Earth. The 1990 Clean Air Act has provisions for fixing the holes, but repairs will take a long time. Ozone in the stratosphere, a layer of the atmosphere nine to 31 miles above the Earth, serves as a protective shield, filtering out harmful sun rays, including a type of sunlight called ultraviolet B. Exposure to ultraviolet B has been linked to
development of cataracts (eye damage) and skin cancer. In the mid-1970s, scientists suggested that chlorofluorocarbons (CFCs) could destroy stratospheric ozone. CFCs were widely used then as aerosol propellants in consumer products such as hair sprays and deodorants, and for may uses in industry. Because of concern about the possible effects of CFCs on the ozone layer, in 1978 the U.S. government banned CFCs as propellants in aerosol cans.
Since the aerosol ban, scientists have been measuring the ozone layer. A few years ago, and ozone hole was found above Antarctica, including the area of the South Pole. This hole, which has been appearing each year during the Antarctic winter (our summer), is bigger than the continental United States. More recently, ozone thinning has been found in the stratosphere above the northern half of the United States; the hole extends over Canada and up into the Arctic regions (the area of the North Pole). The hole was first found only in winter and spring, but more recently has continued into summer. Between 1978 and 1991, there was a 4-5 percent loss of ozone in the stratosphere over the United States; this is a significant loss of ozone. Ozone holes have also been found over northern Europe.
What could a thinned-out ozone layer do to people's lives? There could be more skin cancers and cataracts. Scientists are looking into possible harm to agriculture, and there is already some evidence of damage to plant life in Antarctic seas. Evidence that the ozone layer is dwindling let 93 nations, including the major industrialized nations, to agree to cooperate in reducing production and use of chemicals that destroy the ozone layer. As it became clear the ozone layer was thinning even more quickly than first thought, the agreement was revised to speed up the phase-out of ozone-destroying chemicals. Unfortunately, it will be a long time before we see the ozone layer repaired. Because of the ozone-destroying chemicals already in the stratosphere and those that will arrive within the next few years, ozone destruction will likely continue for another twenty years.
The 1990 Clean Air Act sets a schedule for ending production of chemicals that destroy stratospheric ozone. Chemicals that cause the most damage will be phased out first. The phase-out schedule can be speeded up if an earlier end to production of ozone-destroying substances is needed to protect the ozone layer. The table on this page on Ozone-destroying chemicals includes "speeded-up" phase-out dates which were proposed by EPA in early 1993. CFCs, Halons, HCFCs (hydrochlorofluorocarbons) and other ozone-destroying chemicals were listed by Congress in the 1990 Clean Air Act and must be phased out. The Act also lets EPA list other chemicals that destroy ozone. EPA issues allowances to control manufacture of chemicals being phased out. Companies can also sell unused allowances to companies still making the chemicals or can use the allowances, within certain limits, to make a different, less ozone-destroying chemical on the phase-out list. In addition to requiring the phasing out of production of ozone-destroying chemicals, the Clean Air Act takes other types to protect the ozone layer. The law requires recycling of CFCs and labeling of products containing ozone-destroying chemicals. The 1990 Clean Air Act also encourages the development of "ozone-friendly" substitutes for ozone-destroying chemicals.
CFCs from car air conditioners are the biggest single source of ozone-destroying chemicals. By the end of 1993, all car air conditioner systems must be serviced using equipment that recycles CFCs and prevents their release into the air. Larger auto service shops were required to start using this special equipment in January 1992. Only specially-trained and certified repair persons will be allowed to buy the small cans of CFCs used in servicing auto air conditioners. As CFCs and related chemicals are phased out, appliances and industrial processes that now use the chemicals will change. For example, industrial and home refrigerators will be changed to use refrigerants that don't destroy ozone. In the meantime, refrigerator servicing and disposal will have to be done in ways that don't destroy ozone. In the meantime, refrigerator servicing and disposal will have to be done in ways that don't release CFCs. Methyl chloroform, also called
1,1,1-trichloro-Methyl chloroethane, which will be phased out by 1996, is a very widely-used solvent found in products such as automobile brake cleaners (often sold as aerosol sprays) and spot removers used to take greasy stains off fabrics. Replacing methyl chloroform in workplace and consumer products will lead to changes in many products and processes. As substitutes are developed for ozone-destroying substances, before the chemicals can be produced and sold, EPA must determine that the replacements will be safe for health and the environment.
Consumer Products:
Hair sprays paints, foam plastic products (such as disposable Styrofoam coffee cups), carburetor and choke sprays-all are consumer products that may be regulated under the 1990 Clean Air Act. These products will be regulated to reduce releases of smog-forming VOCs and ozone-destroying chemicals (CFCs and related chemicals). By May 1993, consumer products containing CFCs and related chemicals identified in the 1990 Clean Air Act as most damaging to the ozone are required to have a warning label. All products containing less destructive ozone- destroying chemicals identified in the 1990 Act must be labeled by 2015. Consumers should be aware of product changes and any safety or health problems that may be caused by the new ozone-safe formulations. Material safety data sheets for the products should be read for health and safety information and information on how to use and dispose of the product. The 1990 Clean Air Act orders EPA to study VOC releases from consumer products and report to Congress by 1993 on whether these products should be regulated. If they are to be regulated, EPA is to list the consumer products that account for at least 80 percent of VOC releases, and issue regulations for product categories, starting with the worst polluters. Labeling, repackaging, chemical formula changes, fees or other procedures may be used to reduce VOC releases.
The ozone layer is a layer of gas present in an upper part of the
atmosphere called the stratosphere; the ozone layer is mostly found
around 9 – 21 miles above sea level. It is useful for life and protects
us from ultraviolet (UV) radiation harmful to our health. Dangers of
continuous exposure to harmful UV rays include immune system
suppression, skin cancer, and cataracts.
Depletion was observed in the ozone layer in late 1970s, which
studies say is caused by gases known as ozone depleting substances
(ODSs). These substances are used in utilities like refrigerators, fire
extinguishers, and aerosols. When they are released and escape to the
stratosphere, they prompt reactions with ozone gas a creating a wide
depletion in the ozone.
An international agreement in 1987 in Montreal, Canada, bars the use
of these gases and encourages that they are replaced with substances
that are not harmful to the ozone layer. This agreement, known as the Montreal Protocol, makes the world see ozone layer depletion as a settled environmental issue.
The layer of the atmosphere below the ozone layer is located from the
sea level up and is known as the troposphere; this is where heat
trapping gases concentrate to trap heat to the earth's surface. Global
warming occurs principally from the troposphere where anthropogenic
emissions join natural Green House Gases (GHGs) to collectively trap
more heat to the earth surface.
Global warming is said to be responsible for several environmental
effects like floods, wild fires, and more. Many believe the solution
for global warming is curbing CO2 emissions. But this can only be done
if it is binding for nations.
Geoengineering is
seen as another option to curb global warming, especially if curbing
emissions is not possible. Geoengineering involves intentional
manipulation of the Earth's climate system to prevent excesses that may
be responsible for warming on the Earth's surface. Geoengineering received attention after British scientists introduced a project and the U.S. Bipartisan Policy Center submitted a report on some of the possible geoengineering procedures that could take place.
Many believe geoengineering may have consequences that are too harsh for our fragile climate system. Proponents of
this procedures believe that if the experiment is carried out and the
unexpected happens, it can be halted immediately, but geoengineering may
just be the solution that we need.
Geoengineering may come sooner or later if global warming clearly
puts the environment in danger. This determines whether the
geoengineering procedures are implemented before are after they are
tested for safety.
Geoengineering for global warming may further deplete the ozone layer, causing more harm than good, according to some scientists. However, this should not stop a procedure that will help planet Earth from the risks faced by global warming.
A report presents
the possibility of geoengineering the ozone layer by injecting oxygen
gas to depleted parts of the ozone layer. Oxygen molecules, oxygen
atoms, and ozone molecules are continually reacting in
the presence of UV light in the ozone layer as reactions that protect
from harmful UV rays. Oxygen can be produced in large quantities, stored
as liquid, and discharged as gas at that level; submitting preference
for oxygen is practically difficult for ozone gas.
Aerodyne and aerostats can be used to convey oxygen in a move to
close the depleted part of the ozone layer and save the planet from
harmful UV radiations. The importance of this geoengineering procedure
may clear in some years from now, and it is not likely to have major
consequences. Gases will be added to a layer of gas and this should not
upset the balance of gases at that level. This research is developing and should be ready for use in a few years.