The banning of CFSs is certainly better than not banning them, but from what I can find on scientific sites, the generally agreed upon date for recovery from the ozone layer damage from CFSs is 2045. However, not only is the Antarctic ozone hole of concern, but it looks like within 5 years there will be an Arctic ozone hole as well. The northern hemisphere is heavily populated, and what happens when there is an ozone hole is not only that hundreds of millions of people are exposed to skin cancer, but some species stop reproducing. So the environmental chaos that ensues from an ozone hole is very serious,and all of the ramifications and cross effects are difficult to predict. Also, the relationship between the ozone holes and other forces tied to global warming are unknown and could be cataclysmic, rather than gradual.
Here is an article I found interesting about some of these subjects, most particularly the Arctic ozone hole situation. If you click on the site there are all sorts of illustrations and links, as well. It's really much more fun than reading the text below, and there are clickable links explaining different aspects of the ozone layer, CFCs, etc.:
An Arctic Ozone Hole, if similar in size to the Antarctic Ozone Hole, could expose over 700+ million people, wildlife and plants to dangerous UV ray levels. The likely hood of this happening seems inevitable based on the deterioration of ozone layer caused by the effects of global warming on the upper atmosphere.
"The formation of an Ozone Hole occurring over the
Arctic will likely happen within the next 20 years"-
Jonathan Shanklin one of The BAS scientists who discovered the Antarctic ozone hole
Professor Jonathan Shanklin of The British Antarctic Study said the loss itself of ozone and the greenhouse effect is causing the upper atmosphere to become colder, which is a condition that facilitates ozone destruction. Professor Shanklin was speaking to Alex Kirby of the BBC Radio Four's environment program Costing the Earth and reportedly said the following -
"The atmosphere is changing, and one of the key changes is that the ozone layer is getting colder. And when it gets colder, particularly during the winter, we can get clouds actually forming in the ozone layer, and these clouds are the key factor.
Chemistry can take place on them that activates the chlorine and makes it very much easier for it to destroy the ozone. It's getting colder because of the greenhouse gases that are being liberated by all the emissions we have at the surface.
We think that within the next 20 years we are likely to see an ozone hole perhaps as big as the present one over Antarctica but over the North Pole."
Joseph Farman, Brian Gardiner and Jonathan Shanklin, are the BAS scientists who discovered the Antarctic ozone hole.
Professor Shanklin also is the Director of the British Astronomical Association's Comet Section and the President of the Cambridge Natural History Society
Arctic Ozone Hole in The Near Future?
May 25,2000-Upper atmospheric conditions in The Northern Hemisphere are becoming similar to those of the Antarctic. The result of this could be the formation of an "Arctic Ozone Hole" or "low ozone event". The alarming difference is that there are millions of people that live in the area that will be exposed to this deadly radiation. These conditions could expose large numbers of people and animals to more ultraviolet radiation, which can cause skin cancer and disrupt reproduction of some animals and destroy plant life.
December 2,1999
An Arctic " low ozone event" could easily be blown south by high-altitude winds, and appear over populated areas of The United States, Canada, Europe and Asia. It could trigger public alerts against going out in the sun without protective clothing across The Northern Hemisphere. Experts predict that an estimated 10 % reduction in the ozone layer will result in a 25 % increase in non-melanoma skin cancer rates for temperate latitudes by the year 2050.A larger reduction in the ozone layer could cause "epidemic" like outbreaks of skin cancer and other associated maladies.
ARCTIC OZONE MAY NOT RECOVER AS EARLY AS PREDICTED
Text From NASA Press Release 5/25/2000
The ozone layer that protects life on Earth may not be recovering from the damage it has suffered over the Arctic region as quickly as scientists previously thought, according to a paper published in the May 26 issue of the journal Science. Specifics of the research also will be presented at the annual meeting of the American Geophysical Union in Washington, DC, on May 31.
More polar stratospheric clouds than anticipated are forming high above the North Pole, causing additional ozone loss in the sky over the Arctic, according to Dr. Azadeh Tabazadeh, lead author of the paper and a scientist at NASA's Ames Research Center in California's Silicon Valley. The stratosphere comprises Earth's atmosphere from about 9 to 25 miles (about 15 to 40 kilometers) altitude and includes the ozone layer.
"Polar stratospheric clouds provide a 'double-whammy' to stratospheric ozone. They provide the surfaces which convert benign forms of chlorine into reactive, ozone-destroying forms, and they remove nitrogen compounds that act to moderate the destructive impact of chlorine," said Dr. Phil DeCola, Atmospheric Chemistry Program Manager at NASA Headquarters, Washington, DC.
"The Arctic has become colder and more humid, conditions that promote formation of more polar stratospheric clouds that take part in polar ozone destruction. The main conclusion of our study is that if this trend continues, Arctic clouds will remain longer in the
stratosphere in the future," Tabazadeh said.
"An ozone hole forms every spring over the Antarctic in the Southern Hemisphere which is colder than the Arctic," said Tabazadeh. "The Arctic has been getting colder and is becoming more like the Antarctic; this could lead to more dramatic ozone loss in the future over the Northern Hemisphere, where many people live."
NASA's Upper Atmosphere Research Satellite
Researchers used data from NASA's Upper Atmosphere Research Satellite to analyze cloud data from both the north and south polar regions for the study. "What we found from the satellite was that polar stratospheric clouds currently last twice as long in the Antarctic as compared to the Arctic," Tabazadeh said. "However, our calculations show that by 2010 the Arctic may become more 'Antarctic-like' if Arctic temperatures drop further by about 5 to 7 degrees Fahrenheit (about 3 to 4 degrees Celsius)," she said.
Environment Canada Nov 30 1999 ozone image
When Arctic polar stratospheric clouds last longer, they can precipitate, removing nitrogen from the upper atmosphere, which increases the opportunity for chlorine compounds to destroy ozone more efficiently. The polar stratospheric clouds involved in the reactions contain nitric acid and water, according to researchers who discovered these clouds in 1986.
"Data from the Microwave Limb Sounder on UARS have provided the first opportunity to observe nitric acid throughout the Arctic and the Antarctic over a period of many years," said Michelle Santee, a scientist at NASA's Jet Propulsion Laboratory, Pasadena, CA, who is a co-author of the Science paper. "The continued presence of nitric acid in the Arctic winter -- which is not the case in the Antarctic -- helps to moderate ozone loss by reducing the amount of reactive chlorine, but this could change in the future," she added.
More than a decade ago, scientists determined that human-made chlorine and bromine compounds cause most ozone depletion. Manufacturers made the chlorine compounds,chloroflourocarbons or "CFCs," for use as refrigerants, aerosol sprays, solvents and foam-blowing agents. Fire fighters used bromine-containing halogens to put out fires. Manufacture of CFCs ceased in 1996 in signatory countries under the terms of the Montreal Protocol and its amendments.
The Montreal Protocol bans CFC emissions. As a result, the chlorine concentration in the upper atmosphere is already starting to decline, according to Tabazadeh. "Scientists used to believe that as chlorine levels decline in the upper atmosphere, the ozone layer should slowly start to recover. However, greenhouse gas emissions, which provide warming at the Earth's surface, lead to cooling in the upper atmosphere. This cooling promotes formation of the kind of polar stratospheric clouds that contribute to ozone loss," she added. "Several recent studies, including this one, show that ozone recovery is more complex and will take longer than originally thought," she explained.
Data compiled from The British Antarctic Study, NASA, Environment
Canada, UNEP,EPA and other sources as stated and credited . Updated Daily.
Researched By Charles Welch
theozonehole.com |
