Stratospheric Ozone Layer
Depletion
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Page 11
Monitoring
Ozone From Space
Scientists agree that much remains to be
learned about the interactions that affect ozone. To create accurate models,
scientists must study simultaneously all of the factors affecting ozone
creation and destruction. Moreover, they must study these factors from space
continuously, over many years, and over the entire globe. NASA's Earth
Observing System (EOS) will allow scientists to study ozone in just this way.
The EOS series of satellites will carry a sophisticated group of instruments
that will measure the interactions of the atmosphere. These measurements will
increase dramatically our knowledge of the chemistry and dynamics of the upper
atmosphere and our understanding of how human activities are affecting Earth's
protective ozone layer.
A
graphic example of what satellites can reveal is shown below.
This
figure shows the difference in the thickness of the ozone layer over North
America between 1979 and 1994. By looking closely at the colors on the graph,
the loss of ozone over North America can be seen quite clearly. Most
noticeably, the large white portion of highest ozone concentration has receded
away from the areas of America that release CFCs.
A
dramatic example such as this makes the problem very clear. In only fifteen
years, the ozone layer has been degraded significantly. Luckily, something has
been done about it.
In
response to the Montreal Protocol and public pressure resulting from the
findings of scientists, governments around the world began passing legislation
that restricted or banned the use of CFCs. The United States was no different.
Individual state legislatures as well as the Congress passed laws banning CFCs.
These laws grew more stringent and broadened to encompass more products as time
passed. By the 1990's, CFCs had been banned in the United States with only
slight exceptions for medical and other highly specialized uses. Even with
these types of regulations, it was important that the corporations of the world
agreed to the Montreal Protocol and other regulations.
