Scientific Assessment of Ozone Depletion: 2006

The 2006 WMO/UNEP assessment, Scientific Assessment of Ozone Depletion: 2006, contains the most up-to-date understanding of ozone depletion and reflects the thinking of 310 international scientific experts who contributed to its preparation and review. Co-chairs of this Ozone Assessment were Dr. Daniel L. Albritton of the NOAA ESRL Chemical Sciences Division, Dr. Ayité-Lô Nohende Ajavon of the Université de Lomé, and Dr. Robert T. Watson of the World Bank. Other members of the ESRL Chemical Sciences Division made substantial contributions to the report, serving as lead authors, co-authors, contributors, reviewers, coordinating editor, and editorial and computing support staff.

This Ozone Assessment consists of the Executive Summary, eight detailed chapters and Twenty Questions and Answers About the Ozone Layer: 2006 Update, listed with the names of the Lead Authors:

Chapter 1. Long-Lived Compounds Cathy Clerbaux (France) Derek Cunnold (USA)

Chapter 2. Halogenated Very Short-Lived Substances Kathy Law (France) Bill Sturges (UK)

Chapter 3. Global Ozone: Past and Present Martyn Chipperfield (UK) and Vitali Fioletov (Canada)

Chapter 4. Polar Ozone: Past and Present Paul Newman (USA) Markus Rex (Germany)

Chapter 5. Climate-Ozone Connections Mark Baldwin (USA) Martin Dameris (Germany)

Chapter 6. The Ozone Layer in the 21^st Century Greg Bodeker (New Zealand) Darryn Waugh (USA)

Chapter 7. Surface Ultraviolet Radiation: Past, Present, and Future Alkiviadis Bais (Greece) Dan Lubin (USA)

Chapter 8. Halocarbon Scenarios, Ozone Depletion Potentials, and Global Warming Potentials John Daniel (USA) Guus Velders (Netherlands)

Twenty Questions and Answers About the Ozone Layer: 2006 Update David W. Fahey (USA)

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Executive Summary

The Executive Summary gives a synopsis of major scientific findings of the eight chapters of the full report:

• Preface
• Introduction
• Figure 1: Ozone-Depleting Substances, the Ozone Layer, and UV Radiation: Past, Present, and Future
• Recent Major Findings and Current Scientific Understanding
• Ozone-Depleting Substances
• Ozone, Ultraviolet Radiation, and Other Related Changes to Date
• The Future of the Ozone Layer and Surface UV Radiation
• Additional Scientific Evidence and Related Information
• Long-Lived Ozone-Depleting Substances
• Halogenated Very Short-Lived Substances
• Global Ozone (60°S-60°N)
• Polar Ozone
• Impact of Climate Change
• The Ozone Layer in the 21^st Century
• UV Radiation and Its Changes
• Ozone Depletion Potentials and Global Warming Potentials
• Implications for Policy Formulation

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Twenty Questions and Answers About the Ozone Layer: 2006 Update

In the 2006 Ozone Assessment, the international scientific community included this section to answer several of the general questions that are most frequently asked by students, the general public, and leaders in industry and government. A draft of the update of this component of the 2006 Assessment was reviewed and discussed by the 77 scientists who attended the Panel Review Meeting for the 2006 report in June 2006. In addition, subsequent contributions, reviews, or comments were provided by individuals listed on the inside back cover .

A comprehensive Q&As poster and individual components, including each question and associated figures:

0. INTRODUCTION

1. OZONE IN OUR ATMOSPHERE
1. What is ozone and where is it in the atmosphere?
2. How is ozone formed in the atmosphere?
3. Why do we care about atmospheric ozone?
4. Is total ozone uniform over the globe?
5. How is ozone measured in the atmosphere?
2. THE OZONE DEPLETION PROCESS
6. What are the principal steps in stratospheric ozone depletion caused by human activities?
7. What emissions from human activities lead to ozone depletion?
8. What are the reactive halogen gases that destroy stratospheric ozone?
9. What are the chlorine and bromine reactions that destroy stratospheric ozone?
10. Why has an "ozone hole" appeared over Antarctica when ozone-depleting gases are present throughout the stratosphere?
3. STRATOSPHERIC OZONE DEPLETION
11. How severe is the depletion of the Antarctic ozone layer?
12. Is there depletion of the Arctic ozone layer?
13. How large is the depletion of the global ozone layer?
14. Do changes in the Sun and volcanic eruptions affect the ozone layer?
4. CONTROLLING OZONE-DEPLETING GASES
15. Are there regulations on the production of ozone-depleting gases?
16. Has the Montreal Protocol been successful in reducing ozone-depleting gases in the atmosphere?
5. IMPLICATIONS OF OZONE DEPLETION
17. Does depletion of the ozone layer increase ground-level ultraviolet radiation?
18. Is depletion of the ozone layer the principal cause of climate change?
6. STRATOSPHERIC OZONE IN THE FUTURE
19. How will recovery of the ozone layer be identified?
20. When is the ozone layer expected to recover?

ADDITIONAL TOPICS

• Global Ozone Dobson Network
• Understanding Stratospheric Ozone Depletion
• Heavier-Than-Air CFCs
• Replacing the Loss of "Good" Ozone in the Stratosphere
• The Discovery of the Antarctic Ozone Hole
• The Anomalous 2002 Antarctic Ozone Hole