An unexpected and persistent increase in global emissions of ozone-depleting CFC-11 S.A. Montzka 1 , G. Dutton 1,2 , P. Yu 2,3 , E. Ray 2,3 , R. Portmann 3 , J. Daniel 3 , L. Kuijpers 4 , B.D. Hall 1 , D Mondeel 1,2 , C. Siso 1,2 , J. D. Nance 1,2 , M Rigby 5 , A.J. Manning 6 , L. Hu 1,2 , F. Moore 1,2 , B.R. Miller 1,2 , and J.W. Elkins 1 . 1 Global Monitoring Division, NOAA/ESRL , Boulder, USA, 2 CIRES , Univ. of Colorado, Boulder, USA, 3 Chemical Sciences, Division, NOAA/ESRL , Boulder, USA 4 A/Gent Consultancy, BV, Venlo, The Netherlands Published last week 5 School of Chemistry, Univ. of Bristol, Bristol, UK 6 UK Met office, Exeter, UK Special thanks to: NOAA and cooperative site personnel: Harvard University, Univ. of Colorado, Scripps, Univ. of Wisconsin Australia (CSIRO), Canada (AES), Ireland (Univ. of Bristol), Israel (Weizmann Inst.) AGAGE community of scientists J. Butler, D. Fahey, S. Reimann, P. Newman, S. Davis, P. Novelli, K. Rosenlof NOAA R&D High Performance Computing Program, NOAA Climate Program Office’s AC4 Program NSF, and DOE 1
NOAA/GMD: Tracking ozone-depleting gas concentrations globally • • • • • ALT SUM • BRW weekly • MHD • hourly • LEF • • • • daily THD HFM • NWR bi-weekly • • (aircraft) MLO Sampling in cooperation with KUM international and national partners: 8 km 8 km 8 km Canada (AES) • • UK (Univ Bristol, UK Met office) Australia (CSIRO) SMO Israel (Weizman Inst.) Ireland • Harvard Univ. Univ of Colorado AGAGE Scripps Univ. Wisconsin CGO PSA • • • SPO 2
Atmospheric CFC-11 CFC-11: a Was the largest contributor to (hemispheric means ppt) 265 Mole fraction (ppt) NH 260 the decline in total atmospheric Concentration Hemispheric mean (ppt) SH 255 Cl from 2007-2012 250 Still accounts for 20-25% of 245 ozone-depleting chlorine 240 Reported global production 235 NOAA/GMD became negligible after 2007 230 In situ & flasks 225 b Global rate (per yr) but: 0.0% 1995 2000 2005 2010 2015 Rate of change (%/yr) -0.2% Significant emissions persist, -0.4% from CFC-11 in old foams -0.6% (“bank”) -0.8% Expectation: -1.0% 3 1 -1.2% 2 After the production phase-out: c -1.4% * emissions should decrease & 3.5 Difference (N – S; ppt) North - South (ppt) 3.0 * the concentration decline should accelerate 2.5 (until it reaches its lifetime-limited value: 2%/yr) 2.0 1.5 3 1995 2000 2005 2010 2015
Atmospheric CFC-11 a Hemispheric mean (hemispheric means ppt) 265 Mole fraction (ppt) NH 260 concentration Concentration Hemispheric mean (ppt) SH 255 250 245 240 235 NOAA/GMD 230 In situ & flasks 225 b Global rate (per yr) 0.0% Global rate of change Rate of change (%/yr) -0.2% -0.4% -0.6% -0.8% -1.0% -1.2% c -1.4% 1995 2000 2005 2010 2015 3.5 Difference (N – S; ppt) North - South (ppt) 3.0 2.5 2.0 1.5 3 1995 2000 2005 2010 2015
Atmospheric CFC-11 a Hemispheric mean (hemispheric means ppt) 265 Mole fraction (ppt) NH 260 concentration Concentration Hemispheric mean (ppt) SH 255 250 245 240 235 NOAA/GMD 230 In situ & flasks 225 b Global rate (per yr) 0.0% Global rate of change Rate of change (%/yr) -0.2% -0.4% -0.6% -0.8% -1.0% -1.2% c -1.4% Hemispheric concentration 3.5 Difference (N – S; ppt) North - South (ppt) difference 3.0 Imply an increase in NH 2.5 2.0 CFC-11 emissions 1.5 3 1995 2000 2005 2010 2015
CFC-11 emissions appear to be increasing dG F11 /dt = Emission Loss When derived with a 3-box-model: (changing 100 Emission or Production (Gg/yr) dynamics?) 90 Emission Emission or Production (Gg/yr) 80 70 13 ± 5 Gg/yr 60 (25%) increase 50 40 Testing this emission record: 30 Incorporate emissions into Reported 20 Global a 3-D CCM using reanalysis 10 Production meteorology 0 1995 2000 2005 2010 2015 Compare CCM-simulated vs. measured trends; differences could suggest changes in dynamics, & incorrect emissions 4
3-D modeling of CFC-11 global concentration decline 0.0% 0.0% 0.0% global concentration (per year) 3-D CCM -0.2% -0.2% -0.2% Rate of Change (per year) Rate of Change (per year) Rate of Change (per year) 3-D CCM with Rate of change in -0.4% -0.4% -0.4% fixed dynamics after 2012 observed -0.6% -0.6% -0.6% 3-D CCM with -0.8% -0.8% -0.8% emissions kept constant after 2012 -1.0% -1.0% -1.0% 3-D Models: WACCM or CAM, -1.2% -1.2% -1.2% Reanalysis met.: 2000 2000 2000 2005 2005 2005 2010 2010 2010 2015 2015 2015 MERRA, MERRA2 Year Year Year or GEOS5 5
3-D modeling of CFC-11 global concentration decline Conclude: 0.0% 0.0% 0.0% global concentration (per year) Dynamical 3-D CCM -0.2% -0.2% -0.2% changes added Rate of Change (per year) Rate of Change (per year) Rate of Change (per year) to the to the Rate of change in -0.4% -0.4% -0.4% CFC-11 observed slowdown** -0.6% -0.6% -0.6% But, data are -0.8% -0.8% -0.8% replicated only with a CFC-11 -1.0% -1.0% -1.0% emission increase. -1.2% -1.2% -1.2% 2000 2000 2000 2005 2005 2005 2010 2010 2010 2015 2015 2015 **See next talk by Year Year Year Pengfei Yu 5
Direct observational evidence for increased CFC-11 emissions: Measurements at MLO, Hawaii * air reaching Hawaii in autumn can be influenced by Eurasian emissions,** 246 225 HCFC-22 which brings higher concentrations of 245 chemicals known to be emitted from CFC-11 (ppt) 220 HCFC-22 (ppt) HCFC-22 (ppt) Eurasia: e.g. , HCFC-22, CH 2 Cl 2 , & CO. CFC-11 (ppt) 244 215 243 H1 210 242 205 241 2010 240 200 g-s/m 3 : 238 1e-9 255 H1 2016 237 250 HCFC-22 (ppt) 1e-12 CFC-11 (ppt) HCFC-22 (ppt) 236 CFC-11 (ppt) 245 L1 235 240 L1 234 235 233 g-s/m 3 : 1e-9 232 230 0.4 0.6 0.8 1 Fraction of year 1e-12 6 ** Lin et al ., Nature Geosci. , 2014
Direct observational evidence for increased CFC-11 emissions: Measurements at MLO, Hawaii * air reaching Hawaii in autumn can be influenced by Eurasian emissions,** 246 246 225 225 HCFC-22 which brings higher concentrations of CFC-11 245 245 chemicals emitted from Eurasia: e.g. , CFC-11 (ppt) 220 220 HCFC-22 (ppt) HCFC-22 (ppt) HCFC-22 (ppt) HCFC-22, CH 2 Cl 2 , & CO. CFC-11 (ppt) CFC-11 (ppt) 244 244 215 215 243 243 210 210 1.0 242 242 Regresssion coeff. (r 2 ) CFC-11 vs. 205 205 0.8 regression coef. (r 2 ) 241 241 HCFC-22 2010 2010 240 240 200 200 0.6 238 238 255 255 2016 2016 0.4 237 237 250 250 HCFC-22 (ppt) CFC-11 (ppt) HCFC-22 (ppt) HCFC-22 (ppt) 0.2 236 236 CFC-11 (ppt) CFC-11 (ppt) 245 245 235 235 0.0 2008 2010 2012 2014 2016 2018 240 240 234 234 Year 235 235 233 233 Only after 2012 does air from eastern Asia contain elevated CFC-11 concentrations 232 232 230 230 0.4 0.4 0.6 0.6 0.8 0.8 1 1 Fraction of year Fraction of year Correlations among HCFC-22, CH 2 Cl 2 , & CO are strong in all years 6
Is the Montreal Protocol being violated? Montreal Protocol controls apply to production and consumption. Are the ‘increased’ emissions from ‘new’ production? Emission or Production (Gg/yr) 100 100 OR: Could a change in 90 90 the escape rate of CFC- Emission Emission or Production (Gg/yr) Emission or Production (Gg/yr) 80 80 11 from the “bank” 70 70 account for the 60 60 increased emission? 50 50 40 40 30 30 With no new production, 20 20 Reported the escape rate from the 10 10 Production ‘bank’ would have had 0 0 7% to double… fraction from bank (%/yr) Implied annual Implied annual release release from bank (%/yr) 6% 5% this seems 4% highly unlikely 3% 2% 1995 2000 2005 2010 2015 Year 7
Conclusions: Based on an analysis of our atmospheric measurements: 1) Emissions of a class 1 ozone-depleting substance, CFC-11, have increased in recent years despite a global ban on production Emissions today are similar to what they were 20 years ago Decline rates for other gases have not slowed similarly. 2) The increased CFC-11 emission is likely from eastern Asia. The exact location or country is not yet identified 3) The results suggest new production, which would be inconsistent with the reported global phase out agreed to in the Montreal Protocol 4) Detecting and diagnosing atmospheric composition changes requires: extensive network of high quality measurements accurate and sophisticated modeling tools …and we are fortunate to have both of these at NOAA 9
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