Transcript SAP_OEWG_20July2015x

From CFCs to HCFCs to HFCs
Report of the Scientific Assessment Panel
Open-Ended Working Group Meeting
20 July 2015 - Paris
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
The information contained in this report largely
derives from the Scientific Assessment of Ozone
Depletion: 2014
Ozone-depleting substances (ODSs)
are decreasing
Tropospheric Chlorine
Source Gases
Tropospheric Bromine
Source Gases
3522 ppt
Anthropogenic
CCl4
3210 ppt
HCFCs
312
otherppt (9%)
15.1 ppt
decline
of chlorine
halon1301
Anthropogenic
CH3CCl3
17.1 ppt
CFC-113
CFC-11
halon1211
CH3Cl
1996
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Natural
Natural
CFC-12
2012
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CH3Br
1996
2012
2
Ozone-depleting substances (ODSs)
are decreasing
Tropospheric Chlorine
Source Gases
Tropospheric Bromine
Source Gases
3522 ppt
Anthropogenic
CCl4
3210 ppt
other
HCFCs
halon1301
Anthropogenic
CH3CCl3
17.1 ppt
CFC-113
CFC-11
halon1211
1996
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Natural
Natural
CFC-12
CH3Cl
15.1 ppt
2 ppt (12%)
decline of Br
2012
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CH3Br
1996
2012
3
Ozone levels seems to have
improved, but cannot say they are
statistically significant
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.
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Stopping all future production of HCFCs has
only a limited effect on the 2015 scenario
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Destruction of all ODS banks by 2020 also
has limited impact on the evolution of ODSs
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Stopping all future emissions
advances ODS recovery by about 11 years
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CFCs emissions continue to decline,
but other compounds are increasing
Let’s zoom in
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In 2013, the emissions of CFCs, HCFCs, and HFCs
were about equal in G tonnes CO2-equivalent
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Consumption
(million tonnes CO2-eq.)
Evolution of strategy to eliminate
ozone depleting substances
1000
800
UNEP
HFC
report
600
400
200
0
1990
2002
2010
Some HFCs are potent greenhouse gases.
e.g., HCFC-134a- GWP~1300 (compare with CFC-12 with GWP ~10,000)
 HFCs are the main replacements in many ODS applications.
 HFCs growth is primarily due to their uses as ODS-substitutes.
 HFCs are increasing rapidly.
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Atmospheric observations show
increases in HFCs
WMO/UNEP 2014 SAP report
 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.
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Using data from
WMO/UNEP 2014
SAP report
Emission (Mt CO2 eq per year)
Emissions of HFCs are increasing
1000
Total
800
HFCs used as ODS
substitutes
600
400
200
0
HFC-23
1980
1990
2000
2010
Year
 HFC emissions are increasing.
 Recent HFC-23 emission changes are consistent with effectiveness
of the CDM in recapture and destruction.
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Uses of HFCs (ODS substitutes)
From Montzka et
al. 2014/2015
 MAC, refrigeration, and other uses are roughly the same.
 Emissions from all uses are increasing at roughly the same
rate.
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Increases are consistent
with estimates
From Montzka et al., 2014/2015
400
350
HFC-134a
Global emission (MtCO2 -eq/yr)
Global emission (MtCO2 -eq/yr)
400
1-box model
Velders (2009)
UNFCCC reported
300
250
200
150
100
50
0
1990
1995
2000
2005
Year
2010
2015
350
300
*
Other HFCs
Consistent with
Velders et al.
2009 Projections
1-box model
Velders (2009)
UNFCC reported
250
200
Emissions
from countries
not reporting
to UNFCCC
HFCs-
150
100
50
0
1990
1995
2000
2005
2010
2015
Year
* HFCs other than 134a and 23, i.e., -125, -43a, -32, -152a, -227ea, 365mfc
 Emissions from countries not expected to report to UNFCCC are
increasing very rapidly.
 Emissions are consistent with Velders et al. 2009 estimates for
total and individual chemicals…. Lends confidence to projections
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ODS contributions to climate forcing were large,
but are declining as ODS levels decrease
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By mid-century, HFCs are beginning to
dominate the total radiative forcing
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Future emissions of HFCs could make
a large contribution to climate change
CFCs and HCFCs
WMO/UNEP 2014 SAP report
Various HFC
Scenarios
 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 CO2 future emissions.
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HFCs contribution to climate change by
future emissions can be large
From UNEP
HFC report
 Radiative forcing by future HFC emissions can be ~25% of
that of CO2 future emissions (scenarios from SRES).
 Future HFC emissions can significantly undermine
achievements of the 450 ppm stabilization targets.
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From UNEP
HFC report
Radiative Forcing (W m-2)
There are ways to avoid large
climate effects of HFCs
Progressively
lower GWP
2000
2010
2020
2030
2040
2050
Year
 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.
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Summary
• ODSs are declining in our atmosphere
• The radiative forcing by CFCs and HCFCs will
decline over the course of the 21st century
• Radiative forcing by future HFC emissions can
be ~25% of that of CO2 future emissions.
• Future HFC emissions may hinder the 450 ppm
CO2 stabilization target.
• Alternatives to use of high GWP HFCs are
available
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Thank you
for
your attention.
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HFC emissions projections
by sectors
Regional
Emissions
Sectoral Emissions
Velders et al.,
2015
(to be
published)
Emission projections for various geographical regions
and usage sectors are becoming available
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By mid-century, HFCs are beginning to
dominate the total radiative forcing
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Evolution of strategy to eliminate
ozone depleting substances
CFCs,
Halons,
CH3Br,
CCl4,
MCF,
etc.
HCFCs
High
GWP
HFCs
Low
GWP
HFCs
Alternate
technologies
Burkholder, Cox, and Ravishankara, 2015
 MP successfully phased out CFCs and is phasing out HCFCs.
 Phase out done via use of substitute chemicals or other
approaches.
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