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  GWPs: - CO 2 : 1 - CFCs: 4,000 – 11,000 Large - HCFCs: 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 1980 levels around 2050 • Polar region: EESC back to 1980 levels 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  – Cooling lower stratosphere  ozone destruction – Circulation changes ozone increase more activation on PSC   Overall effect uncertain Guus Velders, Montreal Protocol and Climate 9

Effects on climate

CO 2 emissions World avoided by the Montreal Protocol Reduction Montreal Protocol of ~11 GtCO 2 -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 CO 2 emissions 10 years Reduction in radiative forcing of ~0.23 Wm -2 in 2010  about 13% of CO 2 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 GtCO 2 -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 GtCO 2 -eq/yr by 2010 (IPCC) • Negative radiative forcing of ozone depletion – IPCC estimate of -0.05 +/- 0.05 W/m 2 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 GtCO 2 -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 GtCO 2 -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 CO 2 -forcing of ~10 years • Montreal 2007 adjustment: – Emissions reduced by 12-15 GtCO 2 -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 (EPA) John Daniel (NOAA) David Fahey (NOAA) Mack McFarland (DuPont) Thank you for your attention

Guus Velders, Montreal Protocol and Climate 19