The year is 2004. Sam and Melissa are standing in a crowd with other graduates of the University of Maine. It is early June in New England, but already the season's first hot spell has settled over the area. As the two wait for their diplomas and look toward their future, the prognosis is more hopeful than it was 18 years before when they were first entering the school system. There are still problems, but there have also been changes. The tide has turned, and for them and the rest of the students about to embark on their lives and careers, the future looks brighter than it did for the previous generation.
There are several reasons for this: The Earth Observing System (EOS) has been in place for several years, and already the data coming out of the program have proved valuable. For example, the EOS data have shown that the ozone "hole" over Antarctica has stopped growing as fast as it was in the late 1980s. At the same time, instruments on board the EOS have shown that the actual amount of chlorine in the stratosphere remains fairly constant. As fewer and fewer