The
Oh my Oh me Ozone Layer
The Earth's ozone layer
protects all life from the sun's harmful radiation, but human activities have
damaged this thin shield oh my. Less
protection from ultraviolet light will, over time, lead to higher skin cancer
and cataract rates and crop damage. The
The Earth's atmosphere is divided
into several layers. The lowest region, the troposphere, extends from the
Earth's surface up to about 10 kilometers (km) in altitude. Virtually all-human activities occur in the
troposphere.
Most atmospheric ozone
is concentrated in a layer in the stratosphere,
about 15-30 kilometers above the Earth's surface. Ozone is a molecule containing three oxygen
atoms O3. It is blue in color
and has a naturally strong odor. Normal
oxygen, which we breathe, has two oxygen atoms and is colorless and
odorless. Ozone is much less common than
normal oxygen. Out of each 10 million air molecules, about 2 million are normal
oxygen, but only 3 are ozone.
However, even the small amount of
ozone plays a key role in the atmosphere.
The ozone layer absorbs a portion of the radiation from the sun,
preventing it from reaching the planet's surface. Most importantly, it absorbs the portion of
ultraviolet light called UVB. UVB has been linked to many harmful effects,
including various types of skin cancer, cataracts, and harm to some crops,
certain materials, and some forms of marine life.
At any given time, ozone molecules
are constantly formed and destroyed in the stratosphere. The total amount,
however, remains relatively stable. The concentration of the ozone layer can be
thought of as a stream's depth at a particular location. Although water is
constantly flowing in and out, the depth remains constant.
While ozone concentrations vary
naturally with sunspots, the seasons, and latitude, these processes are well
understood and predictable. Scientists
have established records spanning several decades that detail normal ozone
levels during these natural cycles. One notable web sight is called TOMS, Each natural reduction in ozone levels has
been followed by a recovery. Recently, however, convincing scientific evidence
has shown that the ozone shield is being depleted well beyond changes due to
natural processes and the damage may be irreversible.
In the 1970s,
scientists first grew concerned that certain chemicals could damage the earth’s
protective ozone layer. In the early 1980s, these concerns were
validated by the discovery of thinning of the ozone layer over Antarctica in
the Southern Hemisphere. While the ozone did not completely disappear in this
area, it was so thin that scientists and the popular press started talking
about an ozone hole.
A compromised ozone
layer -- and the resulting increase in ultraviolet (UV)
radiation hitting the earth’s surface -- can have serious
consequences. Overexposure to UV
radiation in humans can cause a range of health effects,
including skin damage (skin cancers and premature aging), eye damage (including
cataracts), and suppression of the immune system. Scientific studies also suggest a link
between ultraviolet radiation and adverse effects on some animal and plant
life.
Because of the risks
posed by ozone depletion,
leaders from many countries decided to craft a workable solution. Since 1987, over 160 nations have signed a
landmark environmental treaty, the Montreal Protocol
on Substances that deplete the Ozone Layer. The Protocol’s chief aim is to reduce and
eventually eliminate the production and use of man-made ozone depleting
substances, or ODS. By
agreeing to the terms of the Montreal Protocol, signatory nations -- including
the United States -- committed to take actions to protect the ozone layer,
hoping in the long-term to reverse the damage that had been done by the use of
ozone depleting substances.
As part of the United States’ commitment to
implementing the Montreal Protocol, the U.S. Congress amended America’s Clean Air Act, adding provisions (under Title VI)
for protection of the ozone layer. Most
importantly, the amended Act required the gradual end to the production of
chemicals that deplete the ozone layer.
The U.S. federal
agency primarily responsible for the management of air quality and atmospheric
protection issues is the U.S. Environmental Protection Agency.
The Clean Air Act amendments passed by Congress require that EPA develop and
implement regulations
for the responsible management of ozone-depleting substances in the United
States.
Under the Clean Air Act, EPA has created several
regulatory programs to address numerous issues, including:
·
ending the production
of ozone-depleting substances
·
ensuring that refrigerants and halon fire extinguishing agents are
recycled
properly
·
identifying safe and effective alternatives
to ozone-depleting substances
·
banning the release of ozone-depleting refrigerants
during the service, maintenance, and disposal of air conditioners and other
refrigeration equipment
·
requiring that manufacturers label
products either containing or made with the most harmful ODS.
The initial concern about the ozone layer in the 1970's led
to a ban on the use of CFCs as aerosol propellants in several countries,
including the U.S. However, production of CFCs and other ozone-depleting
substances grew rapidly afterward as new uses were discovered.
Through the 1980s, other uses
expanded and the world's nations became increasingly concerned that
these chemicals would further harm the ozone layer. In 1985, the Vienna
Convention was adopted to formalize international cooperation on this issue.
Additional efforts resulted in the signing of the Montreal Protocol in 1987.
The original protocol would have reduced the production of CFCs by half by
1998.
After the original Protocol was
signed, new measurements showed worse damage to the ozone layer than was
originally expected. In 1992, reacting to the latest scientific assessment of
ozone layer, the Parties decided to completely end production of halons by the
beginning of 1994 and of CFCs by the beginning of 1996 in developed countries.
Because of measures taken under the
Protocol, emissions of ozone-depleting substances are already falling. Assuming continued compliance, stratospheric
chlorine levels will peak in a few years and then slowly return to normal. The
good news is that the natural ozone production process will heal the ozone
layer in about 50 years.
With input from
industry groups, environmentalists, and the public, EPA has published a range
of regulations for the protection of the ozone layer. Because of their
relatively high ozone depletion
potential, several man-made compounds including chlorofluorocarbons
(CFCs), carbon
tetrachloride, methyl chloroform,
and halons
were targeted first for phaseout. EPA is developing additional regulations
under its ozone protection program for the continued protection of the
environment and public health.
EPA is also charged
with enforcement
of these regulations. Enforcement actions, which are handled through headquarters and at the local level primarily
through EPA’s ten regional offices,
range from civil fines to criminal prosecutions. To date, several people have
been imprisoned for breaking ozone protection laws, and many more have been
fined.
Besides implementing
and enforcing ozone-protecting regulations in the U.S., EPA continues to work with
other U.S. government agencies, including the State Department, Department of Justice, U.S. Customs Service, as well as with
international governments to pursue ongoing amendments to the Montreal Protocol
and other treaties.
These refinements to the Protocol and other treaties are based on ongoing scientific assessments of
ozone depletion which are coordinated by the United Nations Environment
Programmer and the World
Meteorological Organization, with cooperation from EPA and other
agencies around the globe.
In addition, to help
protect the American public from the health effects of overexposure to UV
radiation, EPA maintains several education and outreach projects. Chief among
these is the UV Index,
a tool that provides a daily forecast of the next day’s likely UV levels in 58
cities across the United States. The UV Index, which EPA launched in
partnership with the National Weather Service,
serves as the cornerstone of EPA’s SunWise School Program,
the goal of which is to educate young children and their caregivers about the
health effects of overexposure to the sun, as well as simple steps that people
can take to avoid overexposure.
In
conclusion, The Ozone is very important part of live that many forget
about. By putting a stop to the
production of chemicals that destroy that all together may be a little unrealistic. There are things we can do on a daily level
to protect the Ozone layer, those are reduction in use of automobiles, use of
non aerosol products and by voting for legislative who will pass stronger
Anti-Pollution laws. Well that’s the Oh
my oh me Ozone layer in a nutshell.