Importance of the Montreal Protocol for ozone layer and climate

1. Guus Velders, The Netherlands Importance of the Montreal Protocol for ozone layer and climate WMO/UNEP Ozone Research Managers Geneva, May 19, 2008

2. 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

3. 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

4. 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: 4,000 – 11,000 - HCFCs: 700 – 2,300 Guus Velders, Montreal Protocol and Climate

5. 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

6. Production scenarios Baseline: • current Montreal Protocol • in agreement with observations • used in WMO (2007) Without 1974 paper Molina and Rowland: 3-7% annual growth Without 1987 Montreal Protocol: 2-3% annual growth Guus Velders, Montreal Protocol and Climate

7. 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

8. 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

9. 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

10. Effects on climate CO2 emissions World avoidedby 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

11. 10 years 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 Velders et al., PNAS, 2007 Guus Velders, Montreal Protocol and Climate

12. 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

13. 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

14. 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

15. 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

16. 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

17. 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

18. 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

19. Thank you foryour attention Study in close collaboration with:Stephen Andersen (EPA)John Daniel (NOAA)David Fahey (NOAA)Mack McFarland (DuPont) Guus Velders, Montreal Protocol and Climate