The Ozone Depletion Phenomenon
Summary
Like an infection that grows more and more virulent, the continent-size hole in Earth 's ozone layer keeps getting bigger and bigger.
Each year since the late 1970s, much of the protective layer of stratospheric ozone above Antarctica has disappeared during September, creating what is popularly known as the ozone hole. The Antarctic hole now measures about 9 million square miles, nearly the size of North America. Less dramatic, still significant, depletion of ozone levels has been recorded around the globe. With less ozone in the atmosphere, more ultraviolet radiation strikes Earth, causing more skin cancer, eye damage, and possible harm to crops.
What is ozone? How did researchers discover its role in Earth 's atmosphere and the devastating consequences of its depletion?
The Problem
For four months of every year, Antarctica 's McMurdo Research Station lies shrouded in darkness. Then the first rays of light peek out over the horizon. Each day, the sun lingers in the sky just a little longer and the harsh polar winter slowly gives way to spring.
Spring also brings another type of light to the Antarctic, a light that harms instead of nurtures. In this season of new beginnings, the hole in the ozone layer reforms, allowing lethal ultraviolet radiation to stream through Earth 's atmosphere.
The hole lasts for only two months, but its timing could not be worse. Just as sunlight awakens activity in dormant plants and animals, it also delivers a dose of harmful ultraviolet radiation. After eight weeks, the hole leaves
Antarctica, only to pass over more populated areas, including New Zealand and Australia. This biologically damaging, high-energy radiation can cause skin cancer, injure eyes, harm the immune system, and upset the fragile balance of an entire ecosystem.
Although, two decades ago, most scientists would have scoffed at the notion that industrial chemicals could destroy ozone high up in the atmosphere, researchers now know that
Like an infection that grows more and more virulent, the continent-size hole in Earth 's ozone layer keeps getting bigger and bigger.
Each year since the late 1970s, much of the protective layer of stratospheric ozone above Antarctica has disappeared during September, creating what is popularly known as the ozone hole. The Antarctic hole now measures about 9 million square miles, nearly the size of North America. Less dramatic, still significant, depletion of ozone levels has been recorded around the globe. With less ozone in the atmosphere, more ultraviolet radiation strikes Earth, causing more skin cancer, eye damage, and possible harm to crops.
What is ozone? How did researchers discover its role in Earth 's atmosphere and the devastating consequences of its depletion?
The Problem
For four months of every year, Antarctica 's McMurdo Research Station lies shrouded in darkness. Then the first rays of light peek out over the horizon. Each day, the sun lingers in the sky just a little longer and the harsh polar winter slowly gives way to spring.
Spring also brings another type of light to the Antarctic, a light that harms instead of nurtures. In this season of new beginnings, the hole in the ozone layer reforms, allowing lethal ultraviolet radiation to stream through Earth 's atmosphere.
The hole lasts for only two months, but its timing could not be worse. Just as sunlight awakens activity in dormant plants and animals, it also delivers a dose of harmful ultraviolet radiation. After eight weeks, the hole leaves
Antarctica, only to pass over more populated areas, including New Zealand and Australia. This biologically damaging, high-energy radiation can cause skin cancer, injure eyes, harm the immune system, and upset the fragile balance of an entire ecosystem.
Although, two decades ago, most scientists would have scoffed at the notion that industrial chemicals could destroy ozone high up in the atmosphere, researchers now know that
References: 1. http://www.epa.gov/ozone/science/sc_fact.html 2. http://www.wisegeek.come/what-is-ozone.htm 3. http://www.beyonddiscover.org/content/view.aps?I=73-23k 4. Sustaining the Earth, Seventh Edition, G. Tyler Miller, Jr. pgs. 269-272