Transcript Climate impacts of ozone-depleting substances and their

(RIVM)
The Netherlands
The role of
hydrofluorocarbons
(HFCs) for ozone and
climate protection
Guus Velders
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August 24, 2015
HFCs offset climate benefits Montreal Protocol
Dual protection Montreal Protocol: to Ozone layer and Climate
change
– Already achieved climate benefits 5-6 times larger than Kyoto
Protocol targets for 2008-2012
Climate benefits can be offset by projected increases in HFCs
– HFC emissions can reach 9-19% of CO2 emissions in 2050
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Range of different chemicals
CFCs: fully halogenated
● CFCl3 (CFC-11), CF2Cl2 (CFC-12), etc.
Other ozone depleting chemicals:
● CF3Br, CF2ClBr (Halons – bromine containing species)
● Methyl bromide/chloride, methyl chloroform, CCl4
Alternatives: HCFCs: partially halogenated
● CHF2Cl (HCFC-22), CH3CFCl2, CH3CF2Cl
Alternatives: HFCs: no chlorine
● CH2FCF3 (HFC-134a), CHF2CF3 (HFC-125), CH3CF3 (HFC-143a)
● New: CF3CF=CH2 (HFO-1234yf), CF3CH=CHF (HFO-1234ze)
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Range of different applications (1)
Refrigeration and air conditioning
● Domestic, commercial and industrial:
– Originally: CFC-11, CFC-12
– Now: HCFC-22, HFCs, NH3, CO2, hydrocarbons
● Mobile air conditioning
– Initially: CFC-12
– Now (since ~1995): HFC-134a (all cars)
Foam blowing: insulation, packaging
● Originally: CFCs
● Now: HFCs, hydrocarbons, others
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Range of different applications (2)
Solvent: Dry cleaning, electronics industry
● Originally: CFCs, carbon tetrachloride (CCl4), methyl chloroform (CH3CCl3)
● Now: - mostly not-in-kind technologies, water, other chemicals
- HFCs for some specialized uses
Aerosols: Metered dose inhalers, spray cans (deodorant, hair)
● Originally: CFC-11
● Now: hydrocarbons, not-in-kind, HFCs (limited uses)
Fire fighting agent in aircraft and high-tech facilities
● Originally: halons and CCl4
● Now: Inert gas (e.g. CO2), water, HFCs
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Ozone depletion through Cl and Br atoms
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Ozone depletion through Cl and Br atoms
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Montreal Protocol to protect ozone layer
● Montreal Protocol of 1987
● Subsequent amendments
● Universal ratification
● EESC is a measure of Cl/Br
available to destroy ozone
● Also important for ozone recovery
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CO2, CH4 and N2O emissions
Very short lived species
Rockets, aircraft
Volcanoes
Geoengeneering
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Montreal Protocol changed chemicals used
● Montreal Protocol on Ozone Depleting Substances
● It caused a change in chemicals used for refrigeration, AC, foam
blowing, cleaning, fire extinguishing, etc.:
CFCs

HCFCs + other techn.
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HFCs + other techn.
● Well known benefits for ozone layer
● CFCs, HCFCs, HFCs are all strong greenhouse gases
● Global Warming Potentials (GWPs):
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CFCs:
HCFCs:
HFCs:
HFOs:
4,700 – 11,000
100 – 2,200
130 – 4,200
<20
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Well known benefits Montreal Protocol
● Large decreases in CFC production (>98%) and emissions (60-90%)
● Concentrations also decreasing
● Emerging evidence of start of ozone layer recovery
● Full recovery before 2050, later in polar regions
WMO (2011)
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Metrics used here
● Impacts on climate expressed by
– CO2-equivalent emissions = Emission x GWPs
– Radiative forcing of climate = Abundance x Radiative eff. (W/m2/ppb)
● Impacts on ozone layer expressed by
– CFC-11-equivalent emissions = Emission x ODPs
– Eq. Eff. Stratospheric Chlorine = Abundance x Frac. release + time delay
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Different metrics for ozone depleting chemicals
● Ozone layer:
– ODP-weighed emissions
– Equivalent Effective Stratospheric
Chlorine (EESC)
● Climate change:
– GWP-weighed emissions
– Radiative forcing
WMO (2011)
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Large climate benefits Montreal Protocol
CO2 emissions
World avoided by
the Montreal Protocol
Reduction Montreal Protocol of
~11 GtCO2-eq/yr
5-6 times Kyoto target
(incl. offsets: HFCs, ozone depl.)
Velders et al., PNAS, 2007
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Radiative forcing leading to climate change
Forcing: delay of ~10 years cf
CO2 emissions
Reduction in radiative forcing of
~0.23 Wm-2 in 2010
 about 13% of CO2 emissions of
human activities
• ~0.1 °C cooling from Montreal
Protocol (Estrada et al.; Pretis and Allen, 2013)
Velders et al., PNAS (2007)
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HCFC growth
● CFC phaseout globally in 2010 
Accelerated increases in HCFCs
● Developing countries:
– HCFC consumption increase: 20%/yr (up to
2007)
– CFC+HCFC increase: 8%/yr
● Starting point new scenarios
● HFC-23 emissions not considered
Montzka et al., GRL (2009)
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HFC: Expected large growth
● HCFCs
– Developed countries: controls since 1996
– Developing countries: controls since 2013
– Phaseout in 2030/2040
 Much of application demand for refrigeration,
AC, heating and thermal-insulating foam production to
be met by HFCs
Montzka, NOAA/ESRL
– Current forcing small (<1% of total GHG forcing)
– Current growth rates of HFCs: 10-15% per year
● Increases directly attributable to Montreal Protocol
● Climate effect is a unintended negative side effect
Photo W.S. Velders
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HFC scenarios
● New HFC scenarios developed
– Unchecked emissions
– Extrapolating developed country use patterns
● Based on
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Increased HCFC consumption developing countries
Atmospheric observations of HCFCs and HFCs
Observed replacements patterns: HCFCs to HFCs
IPCC-SRES: growth rates GDP and population
Provisions Montreal Protocol
Increases in HFC-134a use in mobile AC
Saturation of HFC consumption
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Replacing HCFCs with HFCs
● Refrigeration, air conditioning, foam production
● Replacement scheme developed countries:
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HCFC-22
 35% R404A, 55% R410A, 10% NIK
HCFC-141b  50% HFC-245fa, 50% NIK
HCFC-142b  50% HFC-134a, 50% NIK
R404A, R410A: Blends of HFC-32, -125, -134a, -143a
● Applied to developing countries
● Mobile AC: HFC-134a
● Inhaler:
HFC-134a
● Foam, aerosol: HFC-365mfc,
HFC-152a (minor use)
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HFCs offset climate benefits Montreal Protocol
• In 2010, CFCs could have
reached 15–18 GtCO2-eq yr-1
(in absence of Montreal Protocol)
• In 2050, HFC emissions:
5.5–8.8 GtCO2-eq yr-1
= 9–19% of global CO2
emissions
● Larger in comparison with
CO2 stabilization scenarios
from IPCC/AR4
Velders et al., PNAS, 2009
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Offsets in terms of radiative forcing
● In 2010, reduction due to
Montreal Protocol 0.23 W/m2
(incl. offsets)
● In 2050, forcing HFCs
0.25–0.40 W/m2
– Compared with CO2 (BAU) of
2.9–3.5 W/m2
– Equivalent to that from
6–13 years of CO2 emis.
● In 2050, HFC forcing ~ reduction
from CO2 stabilization scenario
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Montreal Protocol and Kyoto Protocol
● Montreal Protocol:
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Protection of ozone layer (UNEP treaty 1987)
Production and consumption
Gases: CFCs, halons, HCFCs, methyl bromide, etc.
Phase-out schedule (CFCs 2010, HCFCs 2030/2040)
Climate considerations taken into account
Very successful: Universal ratification
● Kyoto Protocol:
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Protection of climate (UN treaty 1997)
Emissions
Basket of 6 gases: CO2, CH4, N2O, HFCs, PFCs, SF6
~5% reduction from 1990 by 2008-2012
Emissions reductions of “gases not covered by the Montreal Protocol”
Successful?
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What is happening in the political arena
● Amendments proposed to include HFCs in Montreal Protocol
– Strong support
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Problem caused by Montreal Protocol
Instruments available
Climate considerations are in the text of the Montreal Protocol
Bali decleration by 100+ countries
– Strong opposition
– HFCs to not destroy ozone
– Already in Kyoto
– Financial/legal concerns
● Sept. 2013: G20 supports initiatives to
use expertise and institutions of Montreal
Protocol to phase down HFCs
● Climate and Clean Air Coalition
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What is happening in industry (car makers)
● Since 1990s all mobile air-conditioners use
HFC-134a (GWP 1370)
● In EU: mobile AC directive:
– Refrigerant should have GWP <150
– From 2011 for new type of vehicles (derogation
until 12/2012)
– In 2013: German car maker still used HFC-134a
 France blocked registration of new Mercedes
● Alternatives for HFC-134a:
– HFC-1234yf (more or less drop in replacement)
– CO2 promoted by German EPA (needs redesign of
engine)
– HFC-152a (flammable)
Honeywell (2008)
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Wide range of HFC lifetimes and GWPs
● Fully saturated HFCs:
– HFC-32, -125, -134a, -143a, -152a
– Lifetimes: 1 to 50 yr
– GWPs: 100 to 4000
● Unsaturated HFCs (HFOs):
– HFC-1234yf, -1234ze
– Lifetimes: days to weeks
– GWPs: ~20 or less
● If current HFC mix (lifetime 15 yr)
were replaced by HFCs with
lifetimes less 1 month  forcing
in 2050 less than current HFC
forcing
Velders et al., Science, 2012
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Changes in types of applications
● CFCs (1980s) used in very emissive applications
● Spray cans, chemical cleaning
● Release within a year
● HFCs used mostly in slow release applications
● Refrigeration, AC: release from 1 – 10 yr
● Foams: release > 10 yr
Velders et al., ACP, 2014
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Role of the banks increases
● Banks: HFCs present in equipment:
refrigerators, AC, foams, etc.
● Bank about 7 times annual emission
● Phaseout in 2020 instead of 2050
● Avoided emission: 91-146 GtCO2-eq
● Avoided bank:
39- 64 GtCO2-eq
 Banks: climate change commitment
● Choices:
● Bank collection, destruction: difficult/costly
● Avoid the buildup of the bank: early phaseout
Velders et al., ACP, 2014
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Alternatives to ODSs and HFCs
● Replacing high-GWP HFCs with substances with low impact on climate:
– Hydrocarbons, CO2, NH3, unsaturated HFCs
– Alternative technologies
● Reducing emissions:
– Changing designs
– Capture and destruction
● Low-climate impact alternatives already available
commercially in several sectors:
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–
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Fiber insulation materials (e.g., mineral wool)
Dry powder asthma inhalers
Hydrocarbons, CO2, ammonia in refrigeration systems
Unsaturated HFCs introduced for foams, aerosols and mobile AC
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Life cycle climate performance (LCCP)
● Important is the total effect on climate
● Direct climate forcings
– GWP-weighted emissions, Radiative forcing
● Indirect climate forcings
– Energy used or saved during the application lifespan
– Energy used to during manufacturing
● Total effect on climate  Life cycle climate performance
● Also important: costs, availability, flammability, toxicity, humidity,
etc.
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Conclusions
● Dual protection Montreal Protocol: to Ozone layer and Climate
change:
● Already achieved climate benefits 5-6 times larger than Kyoto
Protocol targets for 2008-2012
● Climate benefits Montreal Protocol can be preserved by limiting
HFC growth
● Challenge for policymakers: identify how this can be
accomplished
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Work performed in close collaboration with:
David Fahey (NOAA)
John Daniel (NOAA)
Steve Andersen (formerly at EPA)
Mack McFarland (DuPont)
Susan Solomon (MIT)
Thank you for
your attention
References:
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al.,
al.,
al.,
al.,
al.,
Proc. Natl. Acad. Sci., 104, 2007
Proc. Natl. Acad. Sci., 106, 2009
Science, 335, 922, 2012
ACP, 14, 2757, 2014
ACP, 14, 4563, 2014
HFC-134a and its
main IR-frequency
Guus Velders