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 Report of the Scientific Assessment Panel Open-Ended Working Group Meeting 20 July Paris

Ozone-depleting substances (ODSs) are decreasing 312 ppt (9%) decline of chlorine 20 July 2015OEWG meeting Paris2

Ozone-depleting substances (ODSs) are decreasing 2 ppt (12%) decline of Br 20 July 2015OEWG meeting Paris3

Ozone levels seems to have improved, but cannot say they are statistically significant 20 July 2015OEWG meeting Paris4 We have previously reported on the response of the ozone layer to the changes in ODSs. Ozone in the upper stratosphere is increasing, as expected. Both CO2 increases and ODSs decreases contribute to this increase The global ozone and the ozone hole are not getting worse; they appear to be slightly better but it is too early to tell.

Stopping all future production of HCFCs has only a limited effect on the 2015 scenario 20 July 2015OEWG meeting Paris5

Destruction of all ODS banks by 2020 also has limited impact on the evolution of ODSs 20 July 2015OEWG meeting Paris6

Stopping all future emissions advances ODS recovery by about 11 years 20 July 2015OEWG meeting Paris7

CFCs emissions continue to decline, but other compounds are increasing Let’s zoom in 20 July 2015OEWG meeting Paris8

In 2013, the emissions of CFCs, HCFCs, and HFCs were about equal in G tonnes CO 2 -equivalent 20 July 2015OEWG meeting Paris9

Evolution of strategy to eliminate ozone depleting substances Some HFCs are potent greenhouse gases. e.g., HCFC-134a- GWP~1300 (compare with CFC-12 with GWP ~10,000) 20 July 2015OEWG meeting Paris10  HFCs are the main replacements in many ODS applications.  HFCs growth is primarily due to their uses as ODS-substitutes.  HFCs are increasing rapidly. UNEP HFC report Consumption (million tonnes CO 2 -eq.)

Atmospheric observations show increases in HFCs  All HFCs are increasing. Most HFCs are increasing rapidly…  Current HFC abundances are still small – together their abundance is roughly < 115 ppt (excluding HFC-23), i.e., 20% of the current CFC-12 abundance. WMO/UNEP 2014 SAP report 20 July 2015OEWG meeting Paris11

Emissions of HFCs are increasing  HFC emissions are increasing.  Recent HFC-23 emission changes are consistent with effectiveness of the CDM in recapture and destruction. Total HFC-23 HFCs used as ODS substitutes Using data from WMO/UNEP 2014 SAP report 20 July 2015OEWG meeting Paris12

Uses of HFCs (ODS substitutes)  MAC, refrigeration, and other uses are roughly the same.  Emissions from all uses are increasing at roughly the same rate. From Montzka et al. 2014/ July 2015OEWG meeting Paris13

Increases are consistent with estimates  Emissions from countries not expected to report to UNFCCC are increasing very rapidly. From Montzka et al., 2014/ July 2015OEWG meeting Paris14 Consistent with Velders et al Projections Emissions from countries not reporting to UNFCCC HFCs- * * HFCs other than 134a and 23, i.e., -125, -43a, -32, -152a, -227ea, 365mfc  Emissions are consistent with Velders et al estimates for total and individual chemicals…. Lends confidence to projections

ODS contributions to climate forcing were large, but are declining as ODS levels decrease 20 July 2015OEWG meeting Paris15

By mid-century, HFCs are beginning to dominate the total radiative forcing 20 July 2015OEWG meeting Paris16

Future emissions of HFCs could make a large contribution to climate change  Future HFC contribution to climate change (as measured by radiative forcing) can be large. o Radiative forcing by future HFC emissions can be ~25% of that of CO 2 future emissions. CFCs and HCFCs Various HFC Scenarios WMO/UNEP 2014 SAP report 20 July 2015OEWG meeting Paris17

HFCs contribution to climate change by future emissions can be large  Radiative forcing by future HFC emissions can be ~25% of that of CO 2 future emissions (scenarios from SRES).  Future HFC emissions can significantly undermine achievements of the 450 ppm stabilization targets. From UNEP HFC report 20 July 2015OEWG meeting Paris18

There are ways to avoid large climate effects of HFCs  Possible to retain a <1% contribution in 2050 if HFCs with GWP <20 and other alternatives are used, even for the upper range emissions scenarios.  Such alternatives appear to be available.  Impacts of TFA from HFO-1234yf, a potential substitute, are negligible over the the next decade. Longer-term impacts require future evaluations. Radiative Forcing (W m -2 ) Year Progressively lower GWP From UNEP HFC report 20 July 2015OEWG meeting Paris19

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. Alternatives to use of high GWP HFCs are available 20 July 2015OEWG meeting Paris20

Thank you for your attention. 20 July 2015OEWG meeting Paris21

HFC emissions projections by sectors Velders et al., 2015 (to be published) Emission projections for various geographical regions and usage sectors are becoming available Regional Emissions Sectoral Emissions 20 July 2015OEWG meeting Paris22

20 July 2015OEWG meeting Paris23 By mid-century, HFCs are beginning to dominate the total radiative forcing

Evolution of strategy to eliminate ozone depleting substances  MP successfully phased out CFCs and is phasing out HCFCs.  Phase out done via use of substitute chemicals or other approaches. CFCs, Halons, CH 3 Br, CCl 4, MCF, etc. CFCs, Halons, CH 3 Br, CCl 4, MCF, etc. HCFCs High GWP HFCs Low GWP HFCs Alternate technologies Burkholder, Cox, and Ravishankara, July 2015OEWG meeting Paris24