Q: What causes the hole in the ozone layer?
A: The Earth’s atmosphere is split into several layers. The one
closest to the earth, the troposphere, extends about six miles
above the planet’s surface at sea level. Above the troposphere is
the stratosphere. In its upper section is the ozone layer.
Q: What causes the hole in the ozone layer?
A: The Earth’s atmosphere is split into several layers. The one closest to the earth, the troposphere, extends about six miles above the planet’s surface at sea level. Above the troposphere is the stratosphere. In its upper section is the ozone layer.
Ozone, a molecule made up of three atoms of oxygen in the shape of a triangle, has a color – blue – and a distinctive odor. This layer of molecules has been protecting the Earth’s inhabitants from cancer-causing UVB rays for more than a billion years.
Most people know about ozone because of the ozone hole, which is actually a thinning of molecules over a specific area. The most steadily recurring hole was discovered by British scientists in Antarctica in 1985. In 2000 and 2003 the hole hit record sizes, covering more than 10.8 million miles.
In a natural setting, ozone in the earth’s atmosphere remains at relatively steady levels, despite the fact that its molecules are constantly forming and breaking apart. But human activities in the last century have begun to tip the balance. A group of chemicals called chlorofluorocarbons (CFCs), coolants used in things like air conditioning and aerosol hairsprays, are stable enough to escape the troposphere and release their chlorine in the stratosphere.
One chlorine atom can destroy more than 100,000 ozone molecules, and when you consider that only 10 out of every million molecules of air are ozone, that’s a lot.
–Environmental Protection Agency, National Oceanic and Atmospheric Administration, encyclopedia.com
