The importance of the Montreal protocol in protecting climate

download report

Transcript The importance of the Montreal protocol in protecting climate

Guus Velders, The Netherlands
Importance of the
Montreal Protocol
for ozone layer and
climate
WMO/UNEP Ozone Research Managers
Geneva, May 19, 2008
Well known benefits Montreal Protocol
Large decreases in CFC
production (90%) and
emissions (60-90%)
Concentrations also decreasing
Increases for HCFCs and HFCs
WMO (2007)
Guus Velders, Montreal Protocol and Climate
2
Well known benefits Montreal Protocol (2)
• Emerging evidence of start of
ozone layer recovery
• Full recovery around 2050
• Polar regions 10-25 years later
• Recovery can be affected by:
– Future production CFCs, HCFCs
– Production methyl bromide
– Emissions from existing
equipment
– Interaction with climate change
WMO (2007)
Guus Velders, Montreal Protocol and Climate
3
Montreal Protocol provided dual protection:
to Ozone layer and to Climate change
 Climate benefits already achieved larger than Kyoto
Protocol targets for 2008-2012
 Potential for additional climate benefits significant
compared to Kyoto
Reason: CFCs, HCFCs are greenhouse gases  Large
GWPs: - CO2 :
1
- CFCs:
- HCFCs:
4,000 – 11,000
700 –
2,300
Guus Velders, Montreal Protocol and Climate
4
Decrease in production of CFCs
• 1974: Molina and Rowland: CFCs
affect the ozone layer
- Public concern  drop production
• ~1980: Increase in production:
- New applications
- Growth in Asia and Europe
• 1987: Montreal Protocol:
- Restricting prod/use CFCs, halons
• 2010: Global production stop CFC
Guus Velders, Montreal Protocol and Climate
5
Production scenarios
Without 1974 paper
Molina and Rowland:
3-7% annual growth
Without 1987
Montreal Protocol:
2-3% annual growth
Baseline:
- current Montreal Protocol
- in agreement with observations
- used in WMO (2007)
Guus Velders, Montreal Protocol and Climate
6
Concentration scenarios
• Delays compared to prod/emis.
due to long lifetimes
• Exponential growth without early
warning in 1974
• Continued growth without
Montreal Protocol
Velders et al., PNAS, 2007
Guus Velders, Montreal Protocol and Climate
7
Effect on ozone layer
• Mid-latitude: EESC back to 1980levels around 2050
• Polar region: EESC back to 1980levels around 2065:
– Older age of air in polar vortex
• Large ozone depletion without
Montreal Protocol and
amendments
Guus Velders, Montreal Protocol and Climate
8
Ozone layer recovery
• Largest potential reductions:
– Destruction of banks of CFCs
– Destruction of banks of halons
– Limiting future production of HCFCs
• Interaction with climate change:
– Cooling upper stratosphere  ozone increase
– Cooling lower stratosphere  more activation on PSC 
ozone destruction
– Circulation changes
 Overall effect uncertain
Guus Velders, Montreal Protocol and Climate
9
Effects on climate
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
Guus Velders, Montreal Protocol and Climate
10
Radiative forcing leading to climate change
Forcing: delay of ~10 years cf
CO2 emissions
10 years
Reduction in radiative forcing of
~0.23 Wm-2 in 2010
about 13% of CO2 emissions
of human activities
Velders et al., PNAS, 2007
Guus Velders, Montreal Protocol and Climate
11
Ozone-depleting substances not in Kyoto
Total target Kyoto: about 2 GtCO2-eq/yr
• CFCs not included in Kyoto Protocol
–
–
–
–
Already covered and soon to be phased out
Benefits for polluting countries
Separate protocols
Negative offset potentially large
• With Montreal Protocol, CFCs likely included in Kyoto
Protocol, but:
– Effects at least 10 years later
– Starting at much higher baseline
– Harder to eliminate
Guus Velders, Montreal Protocol and Climate
12
Offsetting the climate benefits
• About 80% of ozone depleting-substances replaced by
non-fluorocarbons
• Substitute gases for CFCs
– HFCs and HCFCs
– HFC emissions: 0.9 GtCO2-eq/yr by 2010 (IPCC)
• Negative radiative forcing of ozone depletion
– IPCC estimate of -0.05 +/- 0.05 W/m2 for 1979-2005
• Total offsets about 30% of direct forcing
Guus Velders, Montreal Protocol and Climate
13
Montreal 2007 adjustment: HCFC phase-out
September 21, 2007 in Montreal:
• Adjustment of Montreal Protocol: accelerated HCFC phase-out
• Climate effects taken into account
• Developed countries:
– Phase-out from 2030  2020 (+ intermediate reductions targets)
• Developing countries:
– Freeze in 2012
– Phase-out from 2040  2030 (+ intermediate reductions targets)
– Base level from 2015  average 2009-2010
Guus Velders, Montreal Protocol and Climate
14
Montreal 2007 adjustment: HCFC phase-out
Recovery ozone layer ~3 years
earlier
Reduction in emissions:
• 7-9 Mtonnes HCFCs
• 0.35-0.45 MtCFC-11-eq
• 12-15 GtCO2-eq  ~100 million
cars per year
• Effects depend on alternatives
being used
Guus Velders, Montreal Protocol and Climate
15
Possible additional benefits
• Better containment in
refrigeration
• Destruction of ODS banks
• Alternatives with lower GWPs
• Potential reductions:
(by 2015 in GtCO2-eq/yr)
– CFCs:
0.12
– HCFCs: partly done
– HFC-23: 0.30 (by-product)
– HFCs:
0.44 (alternative
.
chemicals)
Guus Velders, Montreal Protocol and Climate
16
Conclusions
Montreal Protocol provided dual protection:
to Ozone layer and to Climate change
• Already achieved climate benefits 5-6 times larger than
Kyoto Protocol targets for 2008-2012
• Montreal Protocol: delay in CO2-forcing of ~10 years
• Montreal 2007 adjustment:
– Emissions reduced by 12-15 GtCO2-eq (depends on replacements)
– Ozone layer recovery ~3 years earlier
Guus Velders, Montreal Protocol and Climate
17
Conclusions (2)
• Potential for additional climate benefits significant
compared to Kyoto Protocol targets (2008-2012):
– Better containment in refrigeration
– Destruction of CFCs, HCFC in exiting refrigerators, foams
– Alternatives with lower GWPs
Guus Velders, Montreal Protocol and Climate
18
Study in close collaboration
with:
Stephen Andersen
John Daniel
David Fahey
Mack McFarland
(EPA)
(NOAA)
(NOAA)
(DuPont)
Thank you for
your attention
Guus Velders, Montreal Protocol and Climate
19