What has caused the depletion of the ozone layer?

Question

please can someone tell me in a WAY that i would understand. :] thank you

Answer 1

Depletion of the ozone layer happens through anthropogenic (human caused) methods or natural methods.  As mentioned above me the chapman mechanism is how ozone is formed through the exposure of UVB rays and UVC rays on an oxygen molecule.  This method has a way of naturally refreshing the amount of ozone because it is a continuous loop.  

The unnatural break down of ozone is through chemicals known as CFC's (chlorofluorocarbons) and HFC's (hydrofluorocarbons).  These are grouped into the broad category of ODC (ozone depleting chemicals).  What happens is that solar radiation will hit one of these chemicals and strip it of one of its halogen molecules (halogen being Chlorine, bromine flourine).  That Cl molecule will then go and attach to an ozone molecule (O3) and form O2 + ClO.  This creates breathable oxygen (O2) but at the expense of ozone.  THis is the break down of the ozone layer that is occuring in the stratosphere.  

Hope this helps

Answer 2

depletion of ozone layer is mainly caused by the explosive use by fighting in world.

Iran to Iraq & Amrica ect ect

Answer 3

Ozone depletion was first noticed in the 1970's. O3 (ozone) occurs naturally in the stratosphere (2nd layer of atmosphere)  and it is thinnest around the equator and denser towards the poles.  O3 is a hazard at ground level (smog) but in the stratosphere it absorbs harmful UV rays from the sun.

O3 depletes over Antartica (and the Artic somewhat) at certain times of the year, this depletion is caused by the use of man-made chemicals - CFC's (chlorine based) bromine compounds, halogen compounds and Nitrogen oxides (Nox). CFC's were used abundantly until banned and Nox is a product of combustion processes such as Aircraft emissions.

O3 depletion is most marked in the Antartic spring (Sept-Nov).  During winter there is no sunlight and a strong circumpolar wind develops in the middle-lower stratosphere: Polar vortex. This vortex isolates the air over the polar region and the air gets very cold, below -80 degrees C PSC's (polar stratospheric clouds) form which contain Nitric acid trihydrate. Psc's must form for ozone loss to occur, nearly all bromine and chlorine up there comes from humans.  Reactions take place on the surface of these clouds and molecular Chlorine is easily split by sunlight in the spring to form atomic chlorine which is required to destroy the ozone.

Psc's contain nitric acid which reacts with CFC's to form chlorine which catalyzes the destruction of the O3, destruction is greatest when the sun returns.

Sorry it's long but hope it helps a bit!

Answer 4

in simple terms, many reactions happen in the earths atmosphere that deplete the earth ozone layer, but this is reversed by reactions that reform the ozone. check out the "chapman mechanism". this cycle has been sent out of sync by halogen based compounds that have a long lifetime in the atmosphere that destroy the ozone layer in a cycle that recycles the halogen so it can continue to destroy more ozone (you may have heard of CFC's plus iodine compounds from the sea.

Answer 5

chloro flouro carbons

from  refrigerators

Answer 6

OK, I'll try!

Some of the chemicals that were used in fridges, aerosols and many other industries were CFCs or "Freon".

These are harmless at sea level but when they get high in the atmosphere, the energy in sunlight breaks the molecules apart. One part of this broken molecule is what's called a 'chlorine monoxide radical'; nevermind the name, the important thing to understand is that this radical is very energetic. So energetic that when it meets an ozone molecule (O3 or 3 oxygen atoms in one bundle) it breaks it up, keeping one O atom for itself and leaving ordinary oxygen (O2) behind.

If that's all it did, however, this wouldn't be so bad, but it isn't. This radical (now with an extra oxygen atom) is also unstable and the sun's energy breaks IT down, and so on through a few different reactions, each reaction destroying an O3 molecule.

The net results of all these reactions are:

1) 2 x O3 (ozone) molecules become 3 x O2 (oxygen) molecules

2) The chlorine monoxide radical remains - this means it can do the whole thing over, and over, and over again for about 50 years, slowly "destroying the ozone layer"

There are a lot of other factors (most help explain why this only happens at the poles) but I've tried to keep it simple.

CFCs were banned in 1987 but as they last for about 50 years, we do not expect the ozone layer to fully recover until 2040 or so (and then only if no other factor pops up).

Hope this helps.