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Paul A. Newman (USA)SAP co-chairNASA/GSFC
Greenbelt, MD [email protected]
Primarily derived from WMO (2011)
The Montreal Protocol and hydrochlorofluorocarbons
(HCFCs)
HFC Management Workshop Paris, 11-12 July 2014
July 11, 2014 1Workshop on HFC Management
Montreal Protocol signed
Em
issi
on
sC
FC
-11
equ
ival
ent
Meg
ato
nn
es/y
r
1960 1970 1980 1990 2000 2010 20200
1
2
HCFC accelerated phase-out(Montreal – 2007 adjustment)
Emissions of ozone depleting substances has declined under the
Montreal Protocol
July 11, 2014 2Workshop on HFC Management
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.
July 11, 2014 3Workshop on HFC Management
FormulaLifetime
(yr) ODPRadiative
Efficiency100-y GWP
CFC-11 CFCl3 52 1.00 0.25 4750
HCFC-21 CHCl2F 1.7 0.04 0.14 151
HCFC-22 CHClF2 12.0 0.05 0.20 1790
HCFC-123 CHCl2CF3 1.3 0.02 0.14 77
HCFC-124 CHClFCF3 5.9 0.02 0.22 619
HCFC-141b CH3CCl2F 9.4 0.11 0.14 717
HCFC-142b CH3CClF2 18.0 0.06 0.20 2220
HCFC-225ca CHCl2CF2CF3 1.9 0.02 0.20 122
HCFC-225cb CHClFCF2CClF2 5.9 0.03 0.32 606
HCFCs contribute to ozone depletion, and climate change
HCFC-142b
HCFC-22
HCFC-141b
190.0 ppb
19.4 ppb18.7 ppb
PrincipalHCFCs
Low ODPs w/r to CFC-11High GWPsJuly 11, 2014 4Workshop on HFC Management
Emissions are expected to grow over the next decade, but will be phased out in
response to Montreal (2007)
HCFC emissions should soon
begin to decline
Growth of CFCs without MP
HFC emissions are currently expected to
substantially increase in the coming decades to
replace HCFCs (see Dr. Ravishankara talk).
July 11, 2014 5Workshop on HFC Management
HCFCs contributed about 7.5% of the total chlorine to the stratosphere in 2008
Includes HCFC-22, -141b, -142b,
-124
July 11, 2014 6Workshop on HFC Management
HCFCs continue to increase, but are projected to decrease starting in about 2030
July 11, 2014 7Workshop on HFC Management
The 2007 HCFC Amendment leads to a HCFC decrease that
begins in the late 2020s
The 2007 HCFC Amendment leads to a HCFC decrease that
begins in the late 2020s
Observa
tions
Observa
tions
Obs
erva
tions
HCFCs now comprise a considerable bank of ODSs and greenhouse gases
July 11, 2014 8Workshop on HFC Management
HCFC GWP weighted emissions grow in importance
until about 2020
HCFCs are beginning to dominate GWP weighted emissions
Total radiative forcing falls off after about
2020, consistent with the shorter lifetimes of
HCFCs
July 11, 2014 9Workshop on HFC Management
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.
July 11, 2014 10Workshop on HFC Management
