Paul A. Newman (USA) SAP co-chair NASA/GSFC Greenbelt, MD 20771 paul.a.newman@nasa

1. The Montreal Protocol and hydrochlorofluorocarbons (HCFCs)HFC Management Workshop Paris, 11-12 July 2014 Paul A. Newman (USA) SAP co-chair NASA/GSFC Greenbelt, MD 20771 paul.a.newman@nasa.gov Primarily derived from WMO (2011) Workshop on HFC Management

2. Emissions of ozone depleting substances has declined under the Montreal Protocol Montreal Protocol signed 2 Emissions CFC-11 equivalent Megatonnes/yr 1 0 1960 1970 1980 1990 2000 2010 2020 HCFC accelerated phase-out (Montreal – 2007 adjustment) Workshop on HFC Management

3. What are HCFCs? • Hydroclorofluorocarbons (HCFCs) first appeared in the atmosphere in the 1960s to the 1980s. • HCFCs were adopted as “interim” substitutes for CFCs following the Montreal Protocol. • HCFCs are primarily destroyed in the troposphere by reaction with the OH molecule, and some small losses by reactions with oxygen atoms and sunlight. Workshop on HFC Management

4. HCFCs contribute to ozone depletion, and climate change Principal HCFCs HCFC-22 190.0 ppb HCFC-141b 19.4 ppb HCFC-142b 18.7 ppb High GWPs Low ODPs w/r to CFC-11 Workshop on HFC Management

5. Emissions are expected to grow over the next decade, but will be phased out in response to Montreal (2007) HFC emissions are currently expected to substantially increase in the coming decades to replace HCFCs (see Dr. Ravishankara talk). Growth of CFCs without MP HCFC emissions should soon begin to decline Workshop on HFC Management

6. HCFCs contributed about 7.5% of the total chlorine to the stratosphere in 2008 Includes HCFC-22, -141b, -142b, -124 Workshop on HFC Management

7. HCFCs continue to increase, but are projected to decrease starting in about 2030 Observations Observations The 2007 HCFC Amendment leads to a HCFC decrease that begins in the late 2020s Observations Workshop on HFC Management

8. HCFCs now comprise a considerable bank of ODSs and greenhouse gases Workshop on HFC Management

9. HCFCs are beginning to dominate GWP weighted emissions Total radiative forcing falls off after about 2020, consistent with the shorter lifetimes of HCFCs HCFC GWP weighted emissions grow in importance until about 2020 Workshop on HFC Management

10. Summary • HCFCs are interim compounds that have served as replacements for CFCs • HCFCs are weaker ODSs than CFCs, but still contribute a significant contribution to chlorine in the stratosphere. They are also significant GHGs • HCFCs are still increasing in the atmosphere, but should stop increasing in the mid-to-late 2020s. • The 2007 phase-out will successfully reduce 2011-50 HCFC emissions by • 0.6–0.8 ODP-Mt - total • 0.4–0.6 GtCO2-eq per year • The effective chlorine return to 1980 levels is earlier by 4-5 years. Workshop on HFC Management