YES!! IT IS DYING! as sad as it sounds this is the true and i don´t think we are doing something about it!... but what it´s the main problem focus on ? well it is all about the OZONE LAYER but what it´s this layer?...here´s what i found out:
"The ozone layer is a layer in
Earth's atmosphere which contains relatively high concentrations of
ozone (O3). This layer absorbs 97-99% of the
sun's high frequency
ultraviolet light which is potentially damaging to life on Earth.
[1] Over 90% of ozone in earth's atmosphere is present here.
[1]"Relatively high" means a few parts per million—much higher than the concentrations in the lower atmosphere but still small compared to the main components of the atmosphere. It is mainly located in the lower portion of the
stratosphere from approximately
15 km to 35 km above Earth's surface, though the thickness varies seasonally and geographically.
[2] The ozone layer was discovered in
1913 by the French physicists
Charles Fabry and
Henri Buisson. Its properties were explored in detail by the British meteorologist
G. M. B. Dobson, who developed a simple
spectrophotometer that could be used to measure stratospheric ozone from the ground. Between
1928 and
1958 Dobson established a worldwide network of ozone monitoring stations which continues to operate today. The "
Dobson unit", a convenient measure of the total amount of ozone in a column overhead, is named in his honor.
"The ozone hole and its causes"
The Antarctic ozone hole is an area of the Antarctic stratosphere in which the recent ozone levels have dropped to as low as 33% of their pre-1975 values. The ozone hole occurs during the Antarctic spring, from September to early December, as strong westerly winds start to circulate around the continent and create an atmospheric container. Within this "polar vortex", over 50% of the lower stratospheric ozone is destroyed during the Antarctic spring.
[8]As explained above, the overall cause of ozone depletion is the presence of chlorine-containing source gases (primarily CFCs and related halocarbons). In the presence of UV light, these gases dissociate, releasing chlorine atoms, which then go on to catalyze ozone destruction. The Cl-catalyzed ozone depletion can take place in the gas phase, but it is dramatically enhanced in the presence of
polar stratospheric clouds (PSCs).
[9]These polar stratospheric clouds form during winter, in the extreme cold. Polar winters are dark, consisting of 3 months without solar radiation (sunlight). Not only lack of sunlight contributes to a decrease in temperature but also the “polar vortex” traps and chills air. Temperatures hover around or below -80 °C. These low temperatures form cloud particles and are composed of either nitric acid (Type I PSC) or ice (Type II PSC). Both types provide surfaces for chemical reactions that lead to ozone destruction.
The
photochemical processes involved are complex but well understood. The key observation is that, ordinarily, most of the chlorine in the stratosphere resides in stable "reservoir" compounds, primarily hydrogen chloride (HCl) and chlorine nitrate (ClONO2). During the Antarctic winter and spring, however, reactions on the surface of the polar stratospheric cloud particles convert these "reservoir" compounds into reactive free radicals (Cl and ClO). The clouds can also remove NO2 from the atmosphere by converting it to nitric acid, which prevents the newly formed ClO from being converted back into ClONO2.
The role of sunlight in ozone depletion is the reason why the Antarctic ozone depletion is greatest during spring. During winter, even though PSCs are at their most abundant, there is no light over the pole to drive the chemical reactions. During the spring, however, the sun comes out, providing energy to drive photochemical reactions, and melt the polar stratospheric clouds, releasing the trapped compounds.
Most of the ozone that is destroyed is in the lower stratosphere, in contrast to the much smaller ozone depletion through homogeneous gas phase reactions, which occurs primarily in the upper stratosphere.
Warming temperatures near the end of spring break up the vortex around mid-December. As warm, ozone-rich air flows in from lower latitudes, the PSCs are destroyed, the ozone depletion process shuts down, and the ozone hole heals.
WhAt CoUlD wE Do ?
we can actually do a lot about this problem because after all this our house right? so here are some tips:
In 1979, many countries, including the U.S., banned CFCs from being made or used. This was a big step toward fixing the problem. Today, no spray cans contain CFCs. Other chemicals are gradually replacing the CFCs in air conditioners.
But the CFCs already in the atmosphere can take up to 50 years to reach the stratosphere. Once there, they hang around in the stratosphere for many years, doing damage.
Also, the products that still contain CFCs need to be treated with care. One example of this is a car air conditioner. When the air conditioner breaks, or the car is taken to a junkyard, the CFCs need to be carefully taken out and recycled or stored so that they don’t leak into the air.
The future
Scientists originally predicted that the ozone layer would be the thinnest around 2008, then start recovering. But new research shows that other air pollution problems are slowing down the ozone layer’s ability to rebound.
What you can do
Encourage people with cars to have their air conditioners fixed by mechanics who are certified to handle. In Wisconsin, by law, mechanics have to be specially certified to work with CFCs.
Protect your skin and eyes from harmful UV rays when you’re outside.
ce Willis as Dr. Malcolm Crowe
ce Willis as Dr. Malcolm Crowe
