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

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Presentation on theme: "Importance of the Montreal Protocol for ozone layer and climate Guus Velders, The Netherlands WMO/UNEP Ozone Research Managers Geneva, May 19, 2008."— Presentation transcript:

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

2 Guus Velders, Montreal Protocol and Climate2 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)

3 Guus Velders, Montreal Protocol and Climate3 Well known benefits Montreal Protocol (2) Emerging evidence of start of ozone layer recovery Full recovery around 2050 Polar regions years later Recovery can be affected by: –Future production CFCs, HCFCs –Production methyl bromide –Emissions from existing equipment –Interaction with climate change WMO (2007)

4 Guus Velders, Montreal Protocol and Climate4 Montreal Protocol provided dual protection: to Ozone layer and to Climate change Climate benefits already achieved larger than Kyoto Protocol targets for Potential for additional climate benefits significant compared to Kyoto Reason: CFCs, HCFCs are greenhouse gases Large GWPs: - CO 2 : 1 - CFCs: 4,000 – 11,000 - HCFCs: 700 – 2,300

5 Guus Velders, Montreal Protocol and Climate5 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

6 Guus Velders, Montreal Protocol and Climate6 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

7 Guus Velders, Montreal Protocol and Climate7 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

8 Guus Velders, Montreal Protocol and Climate8 Effect on ozone layer Mid-latitude: EESC back to levels around 2050 Polar region: EESC back to levels around 2065: –Older age of air in polar vortex Large ozone depletion without Montreal Protocol and amendments

9 Guus Velders, Montreal Protocol and Climate9 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

10 Guus Velders, Montreal Protocol and Climate10 Effects on climate 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.) CO 2 emissions Velders et al., PNAS, 2007

11 Guus Velders, Montreal Protocol and Climate11 Radiative forcing leading to climate change 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 Forcing: delay of ~10 years cf CO 2 emissions 10 years

12 Guus Velders, Montreal Protocol and Climate12 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

13 Guus Velders, Montreal Protocol and Climate13 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 / W/m 2 for Total offsets about 30% of direct forcing

14 Guus Velders, Montreal Protocol and Climate14 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 (+ intermediate reductions targets) Developing countries: –Freeze in 2012 –Phase-out from (+ intermediate reductions targets) –Base level from 2015 average

15 Guus Velders, Montreal Protocol and Climate15 Montreal 2007 adjustment: HCFC phase-out Recovery ozone layer ~3 years earlier Reduction in emissions: 7-9 Mtonnes HCFCs MtCFC-11-eq GtCO 2 -eq ~100 million cars per year Effects depend on alternatives being used

16 Guus Velders, Montreal Protocol and Climate16 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)

17 Guus Velders, Montreal Protocol and Climate17 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 Montreal Protocol: delay in CO 2 -forcing of ~10 years Montreal 2007 adjustment: –Emissions reduced by GtCO 2 -eq (depends on replacements) –Ozone layer recovery ~3 years earlier

18 Guus Velders, Montreal Protocol and Climate18 Conclusions (2) Potential for additional climate benefits significant compared to Kyoto Protocol targets ( ): –Better containment in refrigeration –Destruction of CFCs, HCFC in exiting refrigerators, foams –Alternatives with lower GWPs

19 Guus Velders, Montreal Protocol and Climate19 Thank you for your attention Study in close collaboration with: Stephen Andersen (EPA) John Daniel (NOAA) David Fahey (NOAA) Mack McFarland (DuPont)


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