An unexpected and persistent increase in global emissions of - - PowerPoint PPT Presentation

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An unexpected and persistent increase in global emissions of - - PowerPoint PPT Presentation

Oct 13, 2022 153 likes •286 views

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 ,

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SLIDE 1

An unexpected and persistent increase in global emissions of ozone-depleting CFC-11

S.A. Montzka1, G. Dutton1,2, P. Yu2,3, E. Ray2,3, R. Portmann3, J. Daniel3, L. Kuijpers4, B.D. Hall1, D Mondeel1,2, C. Siso1,2, J. D. Nance1,2, M Rigby5, A.J. Manning6, L. Hu1,2, F. Moore1,2, B.R. Miller1,2, and J.W. Elkins1.

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 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

Published last week

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SLIDE 2
  • ALT

BRW KUM SPO NWR MLO

  • CGO

SMO

weekly hourly

  • •
  • PSA

MHD THD LEF HFM SUM

bi-weekly

(aircraft)

daily

  • NOAA/GMD: Tracking ozone-depleting gas concentrations globally

8 km 8 km 8 km

Sampling in cooperation with international and national partners:

Canada (AES) UK (Univ Bristol, UK Met office) Australia (CSIRO) Israel (Weizman Inst.) Ireland Harvard Univ. Univ of Colorado AGAGE Scripps

  • Univ. Wisconsin

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SLIDE 3

1.5 2.0 2.5 3.0 3.5

1995 2000 2005 2010 2015

North - South (ppt)

c -1.4%

  • 1.2%
  • 1.0%
  • 0.8%
  • 0.6%
  • 0.4%
  • 0.2%

0.0% Rate of change (%/yr)

b

225 230 235 240 245 250 255 260 265 Hemispheric mean (ppt)

a

Atmospheric CFC-11

NH SH

1 2 3 Mole fraction (ppt) Global rate (per yr) Difference (N – S; ppt)

1995 2000 2005 2010 2015

NOAA/GMD In situ & flasks

CFC-11:

 Was the largest contributor to the decline in total atmospheric Cl from 2007-2012  Still accounts for 20-25% of

  • zone-depleting chlorine

 Reported global production became negligible after 2007 but:  Significant emissions persist, from CFC-11 in old foams (“bank”)

After the production phase-out: * emissions should decrease & * the concentration decline should accelerate

(until it reaches its lifetime-limited value: 2%/yr)

Concentration (hemispheric means ppt)

Expectation:

3

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SLIDE 4

1.5 2.0 2.5 3.0 3.5

1995 2000 2005 2010 2015

North - South (ppt)

c -1.4%

  • 1.2%
  • 1.0%
  • 0.8%
  • 0.6%
  • 0.4%
  • 0.2%

0.0% Rate of change (%/yr)

b

225 230 235 240 245 250 255 260 265 Hemispheric mean (ppt)

a

Hemispheric mean concentration Global rate of change

NH SH

Mole fraction (ppt) Global rate (per yr) Difference (N – S; ppt)

1995 2000 2005 2010 2015

Atmospheric CFC-11

NOAA/GMD In situ & flasks

Concentration (hemispheric means ppt)

3

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SLIDE 5

1.5 2.0 2.5 3.0 3.5

1995 2000 2005 2010 2015

North - South (ppt)

c -1.4%

  • 1.2%
  • 1.0%
  • 0.8%
  • 0.6%
  • 0.4%
  • 0.2%

0.0% Rate of change (%/yr)

b

225 230 235 240 245 250 255 260 265 Hemispheric mean (ppt)

a

NH SH

Hemispheric concentration difference

Mole fraction (ppt) Global rate (per yr) Difference (N – S; ppt)

Atmospheric CFC-11

NOAA/GMD In situ & flasks

Concentration (hemispheric means ppt)

Hemispheric mean concentration Global rate of change Imply an increase in NH CFC-11 emissions

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SLIDE 6

10 20 30 40 50 60 70 80 90 100 Emission or Production (Gg/yr)

dGF11/dt = Emission  Loss

CFC-11 emissions appear to be increasing

Reported Global Production 1995 2000 2005 2010 2015

When derived with a 3-box-model:

Emission or Production (Gg/yr) Emission

13 ± 5 Gg/yr (25%) increase Testing this emission record:

(changing dynamics?)

 Incorporate emissions into a 3-D CCM using reanalysis meteorology  Compare CCM-simulated vs. measured trends; differences could suggest changes in dynamics, & incorrect emissions

4

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SLIDE 7
  • 1.2%
  • 1.0%
  • 0.8%
  • 0.6%
  • 0.4%
  • 0.2%

0.0% 2000 2005 2010 2015 Rate of Change (per year) Year

  • 1.2%
  • 1.0%
  • 0.8%
  • 0.6%
  • 0.4%
  • 0.2%

0.0% 2000 2005 2010 2015 Rate of Change (per year) Year

  • 1.2%
  • 1.0%
  • 0.8%
  • 0.6%
  • 0.4%
  • 0.2%

0.0% 2000 2005 2010 2015 Rate of Change (per year) Year

  • bserved

3-D CCM  3-D CCM with fixed dynamics after 2012 3-D CCM with emissions kept constant after 2012

3-D modeling of CFC-11 global concentration decline

3-D Models: WACCM or CAM, Reanalysis met.: MERRA, MERRA2

  • r GEOS5

Rate of change in global concentration (per year)

5

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SLIDE 8
  • 1.2%
  • 1.0%
  • 0.8%
  • 0.6%
  • 0.4%
  • 0.2%

0.0% 2000 2005 2010 2015 Rate of Change (per year) Year

  • 1.2%
  • 1.0%
  • 0.8%
  • 0.6%
  • 0.4%
  • 0.2%

0.0% 2000 2005 2010 2015 Rate of Change (per year) Year

  • 1.2%
  • 1.0%
  • 0.8%
  • 0.6%
  • 0.4%
  • 0.2%

0.0% 2000 2005 2010 2015 Rate of Change (per year) Year

  • bserved

3-D modeling of CFC-11 global concentration decline

Conclude: Dynamical changes added to the to the CFC-11 slowdown** But, data are replicated only with a CFC-11 emission increase.

**See next talk by Pengfei Yu

3-D CCM Rate of change in global concentration (per year)

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SLIDE 9

230 235 240 245 250 255 232 233 234 235 236 237 238 0.4 0.6 0.8 1 HCFC-22 (ppt) CFC-11 (ppt)

Fraction of year

2016

200 205 210 215 220 225 240 241 242 243 244 245 246 HCFC-22 (ppt) CFC-11 (ppt)

2010

CFC-11 (ppt) HCFC-22 (ppt) HCFC-22 (ppt) CFC-11 (ppt)

* air reaching Hawaii in autumn can be influenced by Eurasian emissions,** which brings higher concentrations of chemicals known to be emitted from Eurasia: e.g., HCFC-22, CH2Cl2, & CO.

Direct observational evidence for increased CFC-11 emissions: Measurements at MLO, Hawaii

HCFC-22

** Lin et al., Nature Geosci., 2014

H1

g-s/m3: 1e-9 1e-12

L1

g-s/m3: 1e-9 1e-12

H1 L1 6

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SLIDE 10

230 235 240 245 250 255 232 233 234 235 236 237 238 0.4 0.6 0.8 1 HCFC-22 (ppt) CFC-11 (ppt)

Fraction of year

2016

230 235 240 245 250 255 232 233 234 235 236 237 238 0.4 0.6 0.8 1 HCFC-22 (ppt) CFC-11 (ppt)

Fraction of year

2016

200 205 210 215 220 225 240 241 242 243 244 245 246 HCFC-22 (ppt) CFC-11 (ppt)

2010

200 205 210 215 220 225 240 241 242 243 244 245 246 HCFC-22 (ppt) CFC-11 (ppt)

2010

CFC-11 (ppt) HCFC-22 (ppt) HCFC-22 (ppt) CFC-11 (ppt)

0.0 0.2 0.4 0.6 0.8 1.0 2008 2010 2012 2014 2016 2018 regression coef. (r2) Year

CFC-11 vs. HCFC-22

Regresssion coeff. (r2)

Direct observational evidence for increased CFC-11 emissions: Measurements at MLO, Hawaii

HCFC-22 CFC-11

Only after 2012 does air from eastern Asia contain elevated CFC-11 concentrations

Correlations among HCFC-22, CH2Cl2, & CO are strong in all years

* air reaching Hawaii in autumn can be influenced by Eurasian emissions,** which brings higher concentrations of chemicals emitted from Eurasia: e.g., HCFC-22, CH2Cl2, & CO.

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SLIDE 11

10 20 30 40 50 60 70 80 90 100 Emission or Production (Gg/yr) 2% 3% 4% 5% 6% 7% 1995 2000 2005 2010 2015 Implied annual release fraction from bank (%/yr) Year

Is the Montreal Protocol being violated? Montreal Protocol controls apply to production and consumption.  Are the ‘increased’ emissions from ‘new’ production?

OR: Could a change in the escape rate of CFC- 11 from the “bank” account for the increased emission? With no new production, the escape rate from the ‘bank’ would have had to double…  this seems highly unlikely

10 20 30 40 50 60 70 80 90 100 Emission or Production (Gg/yr)

Emission

Reported Production

Implied annual release from bank (%/yr) 7 Emission or Production (Gg/yr)

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SLIDE 12

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

Conclusions:

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