The Hole in the Ozone: Growing or Shrinking?
The hole in the ozone layer has a negative impact on the Earth and its weather patterns. But what actually causes the hole to form and what is being done to combat the problem?
Most of the ozone molecules in the Earth’s atmosphere are found in the stratosphere. During the winter in the southern hemisphere, a wind vortex forms around the South Pole, causing the polar stratosphere to be isolated. Thin clouds of ice, nitric acid, and sulfuric acid form as temperatures drop below -109°F. Chlorofluorocarbons, CFCs, are formed when chemical reactions occur on the surfaces of the ice crystals. With the release of CFCs, depletion of ozone molecules begins, and the ozone hole appears. Over the ensuing winter months, about fifty percent of the total amount of ozone in the atmosphere disappears. Loses of almost ninety percent are not uncommon in some cases. As spring arrives, so do warmer temperatures, which cause the ice to evaporate and the ozone layer recovers.
After discovery of the Antarctic ozone hole in 1985 and much negotiation, the Montreal Protocol on Substances the Deplete the Ozone Layer was established on September 16, 1987 at the Headquarters of the International Civil Aviation Organization in Montreal. The Montreal Protocol mandated that the consumption and production of ozone depleting compounds, including CFCs and carbon tetrachloride, was to be ended by 2000 with methyl chloroform production and consumption ending by 2005.
It’s great that the Montreal Protocol was agreed on and ratified by over 100 countries, but is it actually successful in helping to fight ozone depletion?
The following is a list of a few relevant websites discussing the current and future trends of the ozone:
http://books.google.com/books?id=dD4Xn-rvEMsC&dq=future+of+the+ozone
This site is for a book that says that the issue of the hole in the ozone layer may not be getting smaller and lists reasons why.
http:// theozonehole.com
This site has several links to information about what would be affected if the hole in the ozone got bigger. It also lists reasons why the hole in the ozone layer is shrinking.
http://www.eoearth.org/article/future_changes_in_ozone_in_the_Arctic
This site gives information about the hole in the ozone decreasing in size.
These will be discussed in depth in future posts.
Comments
In your article you state that CFCs are formed on the ice crystals in the stratosphere. I think you meant to say that the Cl atoms are formed from CFCs that were released into the atmosphere by humans. It is the free Cl atoms that catalyze the destruction of ozone.
Posted by: Steve Sternberg | February 15, 2008 4:14 PM
Steve,
The article said that reactions take place in the clouds that produce active forms of CFCs and the CFCs lead to the destruction of the ozone. Perhaps they just left out the part about the CL atoms being formed from the CFCs produced.
Posted by: Carla Petrich | February 17, 2008 12:44 PM
Maybe I am a little farther behind others, but what are the problems caused by a shrinking or growing Ozone layer. I know it has roots in global climate change, but how? Maybe I need a basic overview of where (height) the ozone layer is and its main function.
Posted by: Adam Clark | February 29, 2008 9:41 PM