1. OEWG, Bangkok, Thailand 22 April 2015 The information contained in this report largely derives from the Scientific Assessment of Ozone Depletion: 2014 From CFCs to HCFCs to HFCs World Meteorological Organization United Nations Environment Programme WMO Global Ozone Research and Monitoring Project – Report No. 56 Co-Chairs: Ayité-Lô Ajavon Paul A. Newman John Pyle A.R. Ravishankara Scientific Steering Committee: Co-Chairs & David Karoly Malcolm Ko Theodore Shepherd Susan Solomon Coordinating Editor: Christine Ennis

2. Ozone-depleting substances (ODSs) are decreasing 312 ppt (9%) decline of chlorine

3. Ozone-depleting substances (ODSs) are decreasing 2 ppt (12%) decline of Br

4. In spite of lifetime and bank changes from 2011, the WMO (2015) scenario is about the same

5. Stopping all future production of HCFCs has only a limited effect on the 2015 scenario

6. Destruction of all ODS banks by 2020 also has limited impact on the evolution of ODSs

7. Stopping all future emissions advances ODS recovery by about 11 years

8. CFCs emissions continue to decline, but other compounds are increasing Let’s zoom in

9. In 2013, the emissions of CFCs, HCFCs, and HFCs were about equal in G tonnes CO 2 -equivalent

10. HFCs are increasing in the atmosphere HFC-23 global abundance is growing, and emissions continue to increase

11. ODS contributions to climate forcing were large, but are declining as ODS levels decrease

12. HFC contributions are growing because of the MP, and will eventually offset the climate gains achieved by the regulation of ODSs

13. The combined radiative impact of CFCs, HCFCs, and HFCs will continue to grow over the next few decades

14. By mid-century, HFCs are beginning to dominate the total radiative forcing

16. Summary ODSs are declining in our atmosphere The radiative forcing by CFCs and HCFCs will decline over the course of the 21 st century Radiative forcing by future HFC emissions can be ~25% of that of CO 2 future emissions. Future HFC emissions may hinder the 450 ppm CO 2 stabilization target.