An attempt to quantify An attempt to quantify

fossil fuel COfossil fuel CO22 over over

EuropeEurope

Ute Karstens1, Ingeborg Levin2

1 Max-Planck-Institut für Biogeochemie, Jena2 Institut für Umweltphysik, Universität Heidelberg

How large is the contribution from fossil fuels to the amount

of CO2 in the atmosphere?

… from a modeller’s perspective

February COFebruary CO22 Fluxes Fluxes

Biome-BGC NEE (Churkina et al., 2003)

10-9 kg C m-2 s-1

0 10 20 30 40 50-10

February 2002annual mean 2000

Fossil fuel CO2

(EDGAR V3.2 FT, Olivier et al., 2005)

Heidelberg: February 2002 Heidelberg: February 2002 (REgional (REgional MOdel)MOdel)

Heidelberg: June 2002Heidelberg: June 2002 (REgional (REgional MOdel)MOdel)

Schauinsland: February 2002Schauinsland: February 2002 (REgional (REgional MOdel)MOdel)

Fossil fuel experimentFossil fuel experiment

Objective:

Assess the impact of new « hourly estimates »

of fossil fuel emissions over Europe

at continental sites using different transport

models

Inventories:

• TransCom 3• EDGAR ft 2000 yearly• EDGAR ft 2000 hourly• IER 2000 hourly

Models:• LMDz• TM5• TM3• DEHM• REMO

Fossil fuel experimentFossil fuel experiment

Feb MarJan Apr May Jun Jul Aug Sep Oct Nov Dec2002

How to measure fossil fuel CO2

in the atmosphere?

—› Radiocarbon (14C) in atmospheric CO2 …

… because fossil fuel CO2 contains no 14C

and dilutes atmospheric 14CO2

1414COCO22 monitoring sites in monitoring sites in (Carbo)Europe(Carbo)Europe

Paris

Lutjewad

HeidelbergSchauinsland

JungfraujochKrakow

Kasprowy

Mace Head

REMO mean european fossil fuel CO2 in January 2002 at 130m [ppm]

Measured COMeasured CO22(foss) mixing ratio(foss) mixing ratio

Data provided by R. Neubert (Lutjewad) and K. Rozanski (Krakow)

35

30

25

20

15

10

5

0

35

30

25

20

15

10

5

0

20

15

10

5

0

5

4

3

2

1

0

CO

2 fo

ssil

fuel

[p

pm

]

Comparison with REMOComparison with REMO

35

30

25

20

15

10

5

0

35

30

25

20

15

10

5

0

20

15

10

5

0

5

4

3

2

1

0

CO

2 fo

ssil

fuel

[p

pm

]

Measured COMeasured CO22(foss) mixing ratio(foss) mixing ratio

Geels et al., 2005, CO2 model comparison

Comparison with modelsComparison with models

CO

2 fo

ssil

fuel

[p

pm

] 12

10

8

6

4

2

0

-2

20

15

10

5

0

-5

JULY – 1998 DECEMBER – 1998

mh

d

cbw

sch

jfj

hei

hu

n

pal

tvr

prs

mh

d

cbw

sch

jfj

hei

hu

n

pal

tvr

prs

TM3LMDZ

HANKDEHM

REMOOBS

… but the network of 14C measurements is sparse:

8 - 10 stations across Europe

… and the temporal resolution is poor:

weekly means

14C is an excellent tracer for fossil fuel CO2

—›proxies/surrogates needed

to substitute 14CO2 observations

Carbon Monoxide (CO)

CO/COCO/CO22 fossil fuel emission ratios fossil fuel emission ratios 20002000

EDGAR V3.2 FT 2000 (Olivier et al., 2005)

mmol / mol

10 20 30 40 50 600

annual mean emissionson global 1°x1° grid

IER mean 2000(Scholz et al., IER 2005)

hourly emissionson 50 km x 50 km grid

Comparison of measured and REMO-Comparison of measured and REMO-modelled atmospheric CO and modelled atmospheric CO and

COCO22(foss)(foss)

CO and CO2(foss) corrected with 222Rn(obs)/222Rn(mod)

Comparison of measured and REMO-Comparison of measured and REMO-modelled CO/COmodelled CO/CO22(foss) ratios(foss) ratios

mod

obsmod2

corr2 CO

CO)foss(CO)foss(CO

Mean ratios

[ppb/ppm]:

Observations: 13.5±2.5

REMO & EDGAR:

12.7±0.6

REMO & IER:

11.0±0.8

CO2(foss)corr RMSE

[%]

REMO & EDGAR: 21.4

REMO & IER: 42.7

Conclusions (I):Conclusions (I):

Fossil fuel CO2 emissions in Europe contribute almost half to

the continental CO2 signal.

Monthly mean fossil fuel CO2 levels at urban sites can be

determined by high precision 14CO2 measurements to better

than ±10% in winter and about ±30% in summer.

At remote sites, the mean fossil fuel CO2 signal is small (1-5

ppm) and can be determined by 14CO2 measurements only to

about 30%.

14C-derived fossil fuel CO2 at selected stations is needed to

validate emissions inventories and assess model estimates of

fossil fuel CO2.

Conclusions (II):Conclusions (II):

CO is a potentially applicable surrogate tracer for fossil fuel CO2,

however,

Emissions inventories of CO and fossil fuel CO2 are yet not accurate enough to apply it quantitatively,

Non-fossil CO sources, in particular soil emissions and their temporal variations, strongly influence the results and need to be estimated more accurately,

The catchment area and relative mix of emissions needs to be known accurately, this requires modelling,

Validation at a larger number of sites is necessary e.g. at one site per country, at least in Europe.

Thank you !Thank you !

Radiocarbon Radiocarbon 1414C C ((1414C, radioactive life time C, radioactive life time = 8300 years)= 8300 years)

Natural 14C production by reactions of neutrons from cosmic radiation with atmospheric Nitrogen natural atmospheric background level

Artificial 14C production via atmospheric nuclear weapon tests in the 1950s and 1960s

„Negative 14C source“ via burning of fossil fuels and cement production

0

200

400

600

800

1000

1950 1960 1970 1980 1990 2000

14CO2 Vermunt

14CO2 Jungfraujoch

14C tree rings [Stuiver and Quay, 1981]

14C

[‰]

1985 1990 1995 2000 20050

50

100

150

200

continental reference Schauinsland monthly means Heidelberg monthly means

14

C [‰

]

Long-term Long-term 1414COCO22 observations in observations in EuropeEurope

„clean“ 14CO2

background level in the Alps

Depletion of the 14CO2 level close to fossil fuel sources

Suesseffect

bombtests

Monthly mean fossil fuel COMonthly mean fossil fuel CO22 at at Schauinsland station and in Schauinsland station and in

HeidelbergHeidelberg

mean fossil fuel CO2 offset:

Schauinsland:ca. 1.4 ppm

Heidelberg:ca. 10 ppm

0

50

100

150

200

continental reference Schauinsland monthly means Heidelberg monthly means

1

4C

[‰]

0

5

10Schauinsland

1985 1990 1995 2000 20050

20

40 total offset fossil fuel offset

Heidelberg

foss

il fu

el C

O2 [p

pm

]

Regional Atmospheric Model REMORegional Atmospheric Model REMO

0.5° x 0.5° horizontal resolution 20 vertical layers Semi-hemispheric model domain (> 30°N) Online tracer transport Prescribed emissions and surface fluxes Parameterization of CO chemistry Initial and lateral boundary conditions:

Metorology: ECMWF analyses CO: MOZART global CTM (Horowitz et al., 2003) CO2: TM3 global transport model

(Heimann and Körner, 2003)

Surface fluxes used in REMOSurface fluxes used in REMO

CO Emissions Fossil fuel burning (EDGAR V3.2 extrapolated) Fossil fuel burning in Europe (IER 2000, extrap.) Fuelwood burning (EDGAR V3.2) Agricultural waste burning (EDGAR V3.2) Biomass bruning (Hao and Liu, 1994) Soil emission (Müller, 1992) Ocean emission (Brasseur et al., 1998)

CO2 Surface fluxes Fossil fuel burning (EDGAR V3.2 extrapolated) Fossil fuel burning in Europe (IER 2000, extrap.) Terrestrial Biosphere Model BIOME-BGC

(Churkina et al., 2003) Ocean fluxes (Takahashi et al., 1999)

Comparison of measured and REMO-Comparison of measured and REMO-modelled CO/ffCOmodelled CO/ffCO22 ratios ratios

Mean ratios [ppb/ppm]:

Observations: 13.5±2.5

REMO & EDGAR: 12.7±0.6REMO & IER: 11.0±0.8

EDGAR (only FF): 11.2IER (only FF): 12.4

Comparison of measured and REMO-Comparison of measured and REMO-modelled CO/COmodelled CO/CO22(foss) ratios(foss) ratios

EDGAR(only foss):

34.4

IER(only foss): 28.8mod

obsmod2

corr2 CO

CO)foss(CO)foss(CO

Mean ratios

[ppb/ppm]:

Observations: 13.5±2.5

REMO & EDGAR:

12.7±0.6

REMO & IER:

11.0±0.8

CO2(foss)corr RMSE

[%]

REMO & EDGAR: 21.4

REMO & IER: 42.7

Measured COMeasured CO22(foss) mixing ratio(foss) mixing ratio

Data provided by R. Neubert (Lutjewad) and K. Rozanski (Krakow)

Comparison with REMOComparison with REMO35 ppm

5 ppm

20 ppm

35 ppm