Stratospheric Ozone Depletion

Contents 1 Ozone Depletion and the ozone hole 2 So what's the problem? 3 The future 4 Relevant links

Ozone Depletion and the ozone hole

Often confused with global warming, ozone depletion refers to the decline of the amount of ozone in the Earth's stratosphere (also known as the ozone layer). The reduction is concentrated above the polar regions which led to the term 'ozone hole' being used.

So what's the problem?

• Ozone absorbs Ultra Violet(UV) light. The loss of ozone in the stratosphere results in increased UV rays reaching the surface, including UVB (a higher energy form of UV light).

• UVB is generally accepted to be a contributory factor to skin cancer and the most common forms of skin cancer in humans have been strongly linked to UVB exposure. It is very likely that the increased levels of UVB radiation reaching the surface due to ozone depletion would result in higher rates of skin cancer.

• An increase of UV radiation would also affect crops. A number of economically important species of plants, such as rice, depend on cyanobacteria residing on their roots for the retention of nitrogen. Cyanobacteria are very sensitive to UV light and they would be affected by its increase.

• Stratospheric ozone depletion is therefore an environmental threat with global effects, including ecological and human health risks.

The future

• The adoption of the Montreal Protocol, banning the production of CFCs and halons (as well as related ozone depleting chemicals), has led to these substances gradually being removed from the atmosphere. The campaign to protect the ozone layer represents an extraordinary success story, however complete recovery of the Antarctic ozone layer is not expected to occur until the year 2050 or later.

• We should not be complacent, as there are still places where CFCs are being released into the atmosphere. See:

• www.peopleandplanet.net, China exposed in global CFC racket
• www.eia-international.org, OZONE LAYER UNDER SIEGE FROM SURGING ILLEGAL CFC TRADE

Relevant links

• wikipedia.org, ozone hole
• www.theozonehole.com
• The ozone hole tour
• The US Environmental Protection Agency's Stratospheric Ozone Depletion software includes information and graphics depicting the ozone layer, how ozone is created, causes and effects of ozone depletion, the ozone hole, the greenhouse effect, and how an individual can help prevent ozone depletion.