WMO/UNEP Scientific Assessment of Ozone Depletion: 1998

A full formatted copy of the Executive Summary available here (PDF; 468k). Adobe Acrobat Reader ® is required.

Below, you can view the three major sections of the Executive Summary, plus scan the Table of Contents of the full Assessment report.

• Text of the Executive Summary.

  The Executive Summary gives a synopsis of major scientific findings of the 12 chapters of the full assessment. This portion includes:
  
  • Preface
  • Recent Major Scientific Findings and Observations
  • Supporting Scientific Evidence and Related Issues
    • Recent Halogen and Methane Changes
    • Stratospheric Particles
    • Ozone in the Midlatitudes and Tropics
    • Ozone in High-Latitude Polar Regions
    • Stratospheric Temperatures
    • Tropospheric Ozone
    • Changes in UV Radiation
    • Changes in Climate Parameters
    • Future Halogen Changes
    • Recovery of the Ozone Layer
  • Implications for Policy Formulation
  
  
  

• "Frequently Asked Questions About Ozone"

  The international scientific community included the section in their 1998 assessment called "Frequently Asked Questions About Ozone." In it, they answer several of the general questions that are most frequently asked by students, the general public, and leaders in industry and government. After a general introduction about ozone, the questions addressed are:

  • How can chlorofluorocarbons (CFCs) get to the stratosphere if they're heavier than air?
  • What is the evidence that stratospheric ozone is destroyed by chlorine and bromine?
  • Does most of the chlorine in the stratosphere come from human or natural sources?
  • Can natural changes such as the Sun's output and volcanic erruptions be responsible for the observed changes in ozone?
  • When did the Antarctic ozone hole first appear?
  • Why has an ozone hole appeared over Antarctica when CFCs and halons are released mainly in the Northern Hemisphere?
  • Is there an ozone hole over the Arctic?
  • Is the depletion of the ozone layer leading to an increase in ground-level ultraviolet radiation?
  • Does ozone depletion cause climate change?
  • How severe is the ozone depletion now?
  • Is the ozone layer expected to recover? If so, when?
  
  
  

• List of International Authors, Contributors, and Reviewers of the Assessment.

  Hundreds of scientists from around the world write and review the periodic WMO/UNEP "state-of-the-science" assessments of ozone depletion; hundreds of additional scientists author the studies that are referenced within them. As a result, the WMO/UNEP assessments are truly "global" documents, reflecting the thinking of the international scientific community.

  Over 300 international scientists from the developed and developing world contributed to the preparation and review of the latest WMO/UNEP assessment, Scientific Assessment of Ozone Depletion: 1998. Listed here are the names of those individuals and the supporting organizations and staff.
  
  
  

• Detailed contents of the full report.

  The full WMO/UNEP report, Scientific Assessment of Ozone Depletion: 1998, consists of the "Frequently Asked Questions About Ozone" and 12 detailed chapters, shown below with the names of the Coordinators and Lead Authors:
  

  "Frequently Asked Questions About Ozone" (Coordinator: Gérard Mégie)
  
  

  Part 1. Halocarbon, Ozone, and Temperature Changes
  

  Chapter 1. Long-Lived Ozone-Related Compounds (Lead Authors: Ronald G. Prinn and R. Zander)
  

  Chapter 2. Short-Lived Ozone-Related Compounds (Lead Authors: (Michael J. Kurylo and José M. Rodríguez)
  

  Chapter 3. Global Distributions and Changes in Stratospheric Particles (Lead Authors: Sophie Godin and Lamont R. Poole)
  

  Chapter 4. Ozone Variability and Trends (Lead Authors: Rumen D. Bojkov and Robert Hudson)
  

  Chapter 5. Trends in Stratospheric Temperatures (Lead Authors: Marie-Lise Chanin and V. Ramaswamy)
  
  

  Part 2. Advances in Understanding the Processes Involved
  

  Chapter 6. Upper Stratospheric Processes (Lead Authors: Rolf Müller and Ross J. Salawitch)
  

  Chapter 7. Lower Stratospheric Processes (Lead Authors: A.R. Ravishankara and Theodore G. Shepherd)
  

  Chapter 8. Tropospheric Ozone and Related Processes (Lead Authors: Jos Lelieveld and Anne M. Thompson)
  
  

  Part 3. Impacts of Ozone Changes
  

  Chapter 9. Ultraviolet Radiation at the Earth's Surface (Lead Authors: Jay R. Herman and Richard L. McKenzie)
  

  Chapter 10. Climate Effects of Ozone and Halocarbon Changes (Lead Authors: Claire Granier and Keith P. Shine)
  
  

  Part 4. Predictions of Future Changes
  

  Chapter 11. Halocarbon Scenarios for the Future Ozone Layer and Related Consequences (Lead Authors: Sasha Madronich and Guus J.M. Velders)
  

  Chapter 12. Predicting Future Ozone Changes and Detection of Recovery (Lead Authors: David J. Hofmann and John A. Pyle)
  

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