Introduction: All about Ozone

Like other environmental problems, Ozone Depletion is one that is very troubling, and rightly so, considered as a major environmental issue by all nations on the earth.

Ozone effectsHave you ever felt the sun's intensity ripping through your skin on a hot afternoon? Probably so.

But the sun is no where near the earth. The sun is estimated to be about 150 million kilometers (93 million miles) from our planet earth. Everyday, as the sun rises, we begin to feel the heat. This heat is radiated through millions of space, and yet we still feel it.

The rays from the sun contain Ultra Violet Rays (UV Rays). UV rays is not all bad, because it helps human with Vitamin D. But too much of it is very dangerous. (we shall see why very soon).

Unfortunately, manufacturing activities since the industrial revolution have caused a disturbance in the atmosphere and opened up for more UV rays to come through to the earth. There have been serious consequences, and potentially it can get worse if we do not act responsibly.

To better understand the Ozone Depletion problem, we first need to get a fewterms right. Let's begin with Ozone.

What is Ozone?

Ozone is a natural gas composed of three atoms of oxygen. It chemical symbol is O3. It is blue in color and has a strong odor. Normal oxygen (O2), which we breathe, has two oxygen atoms and is colorless and odorless.

Environmental scientists have classified O3 into two: Good Ozone and Bad Ozone.

Where is the ozone layer

bulletGood Ozone

Good ozone (also called Stratospheric Ozone) occurs naturally in the upper Stratosphere. The stratosphere is the layer of space 6 to 30 miles above the earth's surface.

Where does good Ozone come from?

The air is full of gases reacting with each other, even though our eyes do not see. When UV light strikes (Oxygen) O2 molecules, they are split into two individual O atoms — O and O. When one of the O atoms combine with O2 molecule, ozone (O3) is created.

where does good ozone come from

Even though Ozone is only a small part of the gases in this layer, it plays a vital role because it shields us from the sun's harmful UV rays. It is called Good Ozone, for obvious reasons—because it protects humans, life and animals on earth.

bulletBad Ozone

Bad Ozone is also known as Tropospheric Ozone, or ground level ozone. This gas is found in the troposphere, the layer that forms the immediate atmosphere. Bad Ozone does not exist naturally. Human actions cause chemical reactions between oxides of nitrogen (NOx) and volatile organic compounds (VOC).

Where does bad ozone come from?

Each time there is a reaction of chemicals such as those found in cars, power plants and factory emissions, in the presence of sunlight (UV light), Bad

Ozone is created.

Bad ozone contaminates (dirties) the air and contributes to what we typically experience as "smog" or haze.

Note that this kind of smog is different from the deadly London winter type that killed 4000 people. Smog from bad ozone is usually in the summer, caused by the action of sunlight on a mixture of hydrocarbons and oxides of nitrogen. It is known as Photochemical or Summer Smog.

The Ozone Layer

This is simply a layer in the stratosphere containing a relatively high concentration of ozone.

The Ozone Layer

The earth's atmosphere is divided into several layers, and each layer plays animportant role. The first region extending about 10km upwards from the earth's surface is called the troposphere. Many human activities like mountain climbing, gas balloons and smaller aircrafts operate within this region.

The next layer, extending about 15-60 km is called the stratosphere. The ozone layer is mainly found in the lower portion of the stratosphere from approximately 20 to 30 kilometres (12 to 19 mi) above earth, though the thickness varies seasonally and geographically.

The ozone layer protects the earth from the suns UV Rays. If the ozone layer is depleted by human action, the effects on the planet could be catastrophic.

What is Ozone Depletion?

Ozone layer depletion, is simply the wearing out (reduction) of the amount of ozone in the stratosphere. Unlike pollution, which has many types and causes, Ozone depletion has been pinned down to one major human activity.

Industries that manufacture things like insulating foams, solvents, soaps, cooling things like Air Conditioners, Refrigerators and ‘Take-Away’ containers use something called chlorofluorocarbons (CFCs). These substances are heavier than air, but over time, (2-5years) they are carried high into the stratosphere by wind action.

Ozone destruction by Clorine

Depletion begins when CFC’s get into the stratosphere. Ultra violet radiation from the sun breaks up these CFCs. The breaking up action releases Chlorine atoms. Chlorine atoms react with Ozone, starting a chemical cycle that destroys the good ozone in that area. One chlorine atom can break apart more than 100,000 ozone molecules.

Ozone layer depletion is best illustrated or explained with the Ozone Bucket Analogy. Click button below to have a look.

Ozone depletion explained

There are other Ozone Depleting Substances (ODS) such as methyl bromide used in pesticides, halons used in fire extinguishers, and methyl chloroform used in making industrial solvents.

Other chemicals that naturally destroy Ozone are Noy, Hox, Clx, which belongto the Nitrogen, Hydrogen and Chlorine families.

Measurements of CFCs in the stratosphere are made from gas balloons, aircraft and satellites.

Sadly, there isn’t much humans can do to replenish the depleted Ozone, as it tends to recover slowly by itself. All we can do is to be more responsible with our manufacturing needs so that we do not introduce more CFCs into the air.