The "hole in the ozone layer" was first discovered
in 1956, long before there was a big buzz
Remember, it's called the ozone "layer" not the ozone "shield". That's because it is not a whole piece. Ozone is formed when sunlight hits oxygen
. So wherever there's sunlight and oxygen, ozone is
formed. Sunlight also breaks down
ozone (i'll go into more detail later). So the ozone layer is constantly being broken down and regenerated. So the ozone we measure now is not the same as we
This "hole" in the ozone layer occurs every late winter in the Antarctic. Sometimes it happens to a greater extent than others. This all has to do with chlorine
in the air, the temperature, and the fact
that no sunlight reaches the south pole in winter to form ozone in the first place.
On September 16, 1987, a NASA ER-2 research aircraft measured
a drop in ozone concentration and a rise in the levels of chlorine monoxide while in the stratospheric altitude above the Antarctic.
Many groups like the EPA and NASA distorted
this reading as proof that CFCs (chlorofluorocarbons) were destroying the ozone layer. They predicted mass cases of skin cancer
causing millions of
deaths and crop damage
if CFC produciton was not halted. There was no evidence at all, though, that CFCs were doing any damage. The chief U.S. negotiator, Richard Benedick, in his book
is quoted as saying "...the most extraordinary aspect of the treaty was the imposition os significant costs against unproven future dangers...dangers that rested on
scientific theories rather than on firm data. At the time od the negotiations and signing no measurable evidence of damage existed."
13 years later, there is still no measurable evidence of
The public was left with a distorted view of chlorofluorocarbons and the ozone layer.
Their theory was based on a fact, however. CFCs will break down in ultraviolet radiation and release reactive chlorine. The theory was that if the CFCs oculd be lifted into the air 10,000 meters where
the level of UV would increase dramatically
. CFCs would probably remain stable until they reached the onzone layer where it would be too vulnerable then break down and destroy the all-important
ozone layer. It's a very unstable theory but that did not stop environmentalists. The case was most difficult for the defense which needed to prove that this does not happen. All the prosecution
needed was a theory backed with highly emotional
When the ozone hole didn't show up during the winters of 1989 and 1992, the debate began to disentegrate but NASA came back in 1992 with new reports of high levels of chlorine in the north pole.
Something that had never been seen before, an ozone hole in the arctic! But still, 8 years later there has never been an ozone hole
in the north pole.
The ban on CFCs had planned to phase
them out completely by 1992. Some say there was no hole because of that ban. That simply just doesn't work. The ozone doesn't change from year to year
based on things that humans
do. CFCs have a halflife
of about a century
The big problem the environmentalists and the public had was the "infamous, deadly UV rays". Well there are different kinds of UV rays. The shorter wavelength type, UVC, is responsible for splitting
oxygen molecules, and creating billions of tons
of ozone per second. The longer wavelength type, UVB, breaks it down. Both UVC
are effectively blocked by the ozone layer. The longest
, is not affected by oxygen
or the ozone layer
and passes through freely. Ironically, this
is the wavelength proven to be the cause of melanoma
, the deadly skin cancer.
Skin cancer was the main drive of environmentalists
. And now, it is proven that the ozone layer has nothing to do with protecting us from cancer! Well, imagine if suddenly (magically), what we call
the ozone layer, was completely eliminated. What would happen? More ozone would form immediately
below it in the troposphere
. Protective oxygen is always there, and it is the source of our
Our manmade materials have not have a true effect on the atmosphere
. We would have to try really hard
if we wanted to make a dent. So much more of this chlorine (which is the bad part
in CFCs) occurs naturally than we make. A large volcanic blast
can contribute 100 to 1000 million tons of active chlorine to the atmosphere
, and a large portion of it may very well reach the
stratosphere. Slower eruptions make a slow stream of chlorine, like Mount Erebus which has released 300,000 tons per year for the past 30 years
Salt spray from oceans, forest and brush
contribute an average of 700 million tons annually! All of these natural contributions add up to make a total four to five orders of magnitude greater than the man-made contribution. Also,
take into fact that only a very minor portion of CFCs actually make into the stratosphere
. The molecules are 4 to 8 times heavier than air
easily to the ground and other things
attached to the ground.
On a final note, remember that the first major hole in the ozone above the Antarctic (that we noticed) was in 1956, long before chlorofluorocarbons
were in widespread use. This "hole" is a
naturally occurring event
that happens periodically.
Update: concerning the writeup below by mricicle
, I do not trust the EPA.
I would not rely on the facts that they give me. However, there is no way I can disprove them.
Sources: NASA (National Aeronautics and Space Administration) http://www.nasa.gov Global Warming in a Politically Correct Climate, M. Mihkel Mathiesen EPA (Environmental
Protection Agency) http://www.epa.gov