A recent global study reportedly suggests the Earth's ozone is recovering, indicating an international ban on ozone-depleting chemicals is effective.

Researchers at the Cooperative Institute for Research in Environmental Sciences, located in Boulder, Colo., report finding the planet's ozone depletion rate leveled off between 1996 and 2002. The Boulder (Colo.) Daily Camera reported Tuesday.

Betsy Weatherhead, corresponding author of the study, told the newspaper: "That it hasn't gone down for the last eight years is a big deal. It's very hopeful."

However, she said it likely will take decades before the ozone layer recovers, and it may never stabilize at the levels measured prior to the mid-1970s, when it was determined human-produced chlorine and bromine compounds were destroying the Earth's ozone layer.

The team included researchers from the University of Colorado at Boulder, the National Oceanic and Atmospheric Administration, the University of Wisconsin at Madison, the University of Chicago and the University of Illinois.

The study appears online in the Journal of Geophysical Research.

Copyright 2005 by United Press International