Plans for the 2010 WMO/UNEP Assessment of ozone Depletion Ozone Research Managers Meeting, Geneva, Switzerland May 19, WMO/UNEP Assessment Co-chairs: Ayité-Lô Ajavon (Togo) John Pyle (UK) Paul Newman (USA) A. R. Ravishankara (USA) Scientific Assessment of Ozone Depletion:2010 Colour?

A Little Context: The Assessment Process Important factors: 1.The expertise of the authors. 2.Critical reviews (multiple times) by experts What the assessments are: State of science: What we know & what we dont, framed in policy- useful terms. Scientific documents, prepared & reviewed by the expert communities. Assessed viewpoints, not reviews. One-stop shopping: Science of the ozone layer; Impacts of ozone change; Technology/economics of options. Well-identified customers: Governments (via the Montreal Protocol); Industry; Public; Science community

They dont make policy recommendations. They are not research-planning documents, nor do they push research projects or needs. They do identify gaps in information that may limit informed decision-making. No one assessment report is the final word. Both policy and research are interactive endeavors. What the assessments are not

Key ongoing issues - Levels of ODS and trends - Levels of ozone and its trends - Our understanding of the atmospheric science What is new in science - The impact of climate change on ozone layer recovery - The impact of ozone layer changes on climate and its changes Key requests from the Parties to the Protocol Contents ** Update common questions

Steps: Dates and Tasks Overall Timetable & Some Notable Features Draft outline completed. Lead Authors, Coauthors established Chapter outlines drafted Early 2009: Lead Authors meeting (location?). Late October: 1st drafts due; circulated for internal review. End of 2009: Internal review meeting, Lead Authors, Steering Committee, and a few others. (Washington, USA?) February 2006: 2 nd drafts complete and mail peer review starts. April: mail reviews due; third draft preparation begins. Mid-May: Third draft due; distributed to Panel reviewers. Summer 2010: Panel Review: (Les Diablerets, Switzerland ?) >Lead Authors & a few Coauthors. >~30-40 reviewers. >Final decisions on chapters. >Completed Executive Summary. Late July: Chapters completed. 30 December: preprint volume to UNEP for government distribution. March 2011: final printed copies available

9 Findings from the 2006 Assessment

Findings of the Scientific Assessment Panel (SAP) Ozone Research Managers Meeting, Geneva, Switzerland May 19, WMO/UNEP Assessment Co-chairs: Ayité-Lô Ajavon (Togo) Daniel L. Albritton (USA)* Robert T. Watson (USA)* Scientific Steering Committee: Marie-Lise Chanin (France) Susana Diaz (Argentina) John Pyle (United Kingdom) A.R. Ravishankara (USA) Theodore G. Shepherd (Canada) Please join me in thanking these two great individuals

Scientific Findings 1980 Now 2100 ODS production Global ozone change Ultraviolet radiation change (a) (b) (c) (d) ODS production ODS in the atmosphere Ozone levels – measured and predicted UV levels – based on observations and predictions Ozone-depleting chlorine and bromine in the stratosphere There is even stronger evidence since the 2002 Assessment that the Montreal Protocol is working

The Montreal Protocol is working Ozone-depleting substances are decreasing in the lower atmosphere (where they are emitted) as well as in the stratosphere where the ozone layer is The Montreal Protocol is working as intended ODS Changes in the Lower Atmosphere ODS Changes in the Stratosphere

Ozone observations There are early signs that the ozone layer is starting its expected recovery 2010 ?

Polar ozone changes Polar ozone loss remains large and highly variable The Antarctic ozone hole will persist till around Arctic ozone levels are expected to return to pre values around 2050 The annual variations are expected in the next decades

Ozone depleting substances Methyl chloroform and methyl bromide contributed most to the decline thus far; methyl chloroform will soon be insignificant in the atmosphere Halons peaked in the lower atmosphere around 1998 and are now decreasing Very short-lived halogenated (chlorine and bromine) substances are of greater importance than previously estimated There are many contributors to the decrease in ODS: Methyl Chloroform Methyl Bromide, Halons

Hydrochlorofluorocarbons (HCFCs) continue to increase in the atmosphere. In 2004 they contributed 6% to the lower atmospheric chlorine burden, compared to 5% in HCFC-22 is the most abundant of the HCFCs and is increasing at 3.2% per year. HCFCs HCFC-141bHCFC-142b HCFC-22

ODS are decreasing & the ozone layer is starting its recovery Climate change and ODSs will affect the future of ozone layer Decreases in ODS emissions already achieved by MP is the dominant factor in return to pre-1980 values But failure to continue compliance with the MP could delay or even prevent the recovery of the ozone layer Global ozone layer (60 o S-60 o N) is expected to return to pre-1980 values around 2050 Return of ozone to pre-1980 levels

Benefits to the ozone layer of many options to further reduce ODS have been evaluated Percent reductions in integrated Equivalent Effective Stratospheric Chlorine (EESC) Evaluation of options

Science moves on! The 2006 Assessment was one in a series- more to follow in the future. Thanks to Daniel Albritton and Robert Watson for their leadership! The new co-Chairs of the Scientific Assessment Panel: Prof. Ayité-Lô Ajavon (Togo) Dr. Paul Newman (USA) Prof. John Pyle (United Kingdom) Dr. A. R. Ravishankara (USA) Progress since SAP 2006 Report To follow: What is new since the assessment?

9 Thank you for your attention The assessment reports Executive summary and Twenty Questions and Answers All available upon request