2006 News & Events

The Executive Summary of the international state-of-understanding assessment regarding Earth's ozone layer was released on Friday, August 18, by the World Meteorological Organization and United Nations Environment Programme. Media attended the press conference held in Geneva, Switzerland, and the story was picked up by major media outlets such as Associated Press and Reuters.

Background: The ozone scientific assessments are produced every four years in accordance with the Montreal Protocol on Substances that Deplete the Ozone Layer. Over 190 nations are Parties to the Protocol, which is the international agreement that seeks to protect the protect the stratospheric ozone layer from ozone-depleting substances such as chlorofluorocarbons (used as refrigerants and in other applications) and halons (used as fire extinguishants). The Executive Summary gives the major findings of the full report's eight detailed scientific chapters. The full report is in press and will be available in early 2007.

NOAA and CIRES scientists play key roles in the ozone assessment, including international Cochair (retired Chemical Sciences Division scientist Dan Albritton), Scientific Steering Committee member (Acting CSD Director A.R. Ravishankara), Chapter Lead Author (CSD scientist John Daniel), Lead Author of the Questions and Answers about the Ozone Layer (CSD scientist David Fahey), and Coauthor (GMD's Steve Montzka, Betsy Weatherhead, Kathy Lantz, John Miller, Jim Butler; CSD's Jim Burkholder, Claire Granier, and Bob Portmann). Several others in OAR, NWS, and NESDIS served as contributors and Reviewers, and CIRES/CSD scientist Chris Ennis is Coordinating Editor of the assessment.

The 2006 Executive Summary is posted online. Among its key findings:

1. We now see evidence of not just a turnover, but a downward trend in the abundances of ozone-depleting gases even in the stratosphere, where the ozone layer resides. This gives solid evidence of the effectiveness of the Montreal Protocol.
2. The ozone layer has shown some promising hints of recovery. Outside of the polar regions, its decline has not continued in recent years, and there is a "leveling off" of ozone abundances. In the coming years and in the next assessment in 2010, scientists will be looking for evidence of an actual turnaround and then increase toward pre-1980 values in the ozone abundances outside the polar regions.
3. With this assessment, improved understanding has enabled scientists to make better estimates of when the ozone layer will recover. The anticipated recovery of the ozone layer at midlatitudes is in about 2049, five years later than was estimated in the 2002 ozone assessment. In Antartica, recovery is expected in about 2065, fifteen years later than the prior estimate.
4. The ozone assessment explores several hypothetical scenarios for future emissions of halocarbons, and their implications for the amount of ozone-depleting substances that would occur in the stratosphere as a result.

Significance: NOAA has played a leading role in the international ozone assessment throughout the history of the 1987 U.N. Montreal Protocol. NOAA scientists have served as cochair, leading authors, coauthors, and reviewers in each of the assessments (1988, 1991, 1994, 1998, 2002, and 2006). The document has formed the scientific basis for decisions of the Parties to strengthen the original provisions of the Montreal Protocol to protect the stratospheric ozone layer, which shields the earth surface from harmful levels of solar ultraviolet radiation. The effort, a part of NOAA's Climate Goal/Climate Forcing Program, helps NOAA to meet its mission of providing decision-support scientific information to governments, industry, and the general public.