carbon in the earth system: dynamics and vulnerabilities · the response of the global carbon...

$: Carbon in the Earth System: Dynamics and Vulnerabilities · The response of the global carbon cycle: the airborne fraction of anthropogenic CO 2 XAF = (Atmospheric accumulation)$
Carbon in the Earth System: Dynamics and Vulnerabilities

ESSP Global Carbon Project

(Presenter: Michael Raupach)

Earth System Science Partnership Open Science Conference"Global Environmental Change: Regional Challenges", Beijing, 9-12 November 2006

Two nested ecologies

Ecology of the biosphere• Life is a complex adaptive system (CAS)• Imports (solar) energy, exports entropy, stores information• Evolves by sieving information (genome) about organisms (phenome)• Genomes and phenomes are both carbon-based

Ecology of the anthroposphere• New evolutionary trick: use of exogenous (non-biotic) energy• Easiest energy source: detrital carbon from the biosphere• CAS with biological, technological, social, cultural levels

Signs of Trouble

Now: accelerating CO2 emissions

Future:Emissions GapInertiaVulnerability

The global carbon cycle in the anthropocene

Response

Dimensions:TechnicalPolicyEconomicCultural

Systems approach

Global atmospheric CO2 budgetPep Canadell, Corinne LeQuere, Mike Raupach, Gregg Marland, Skee Houghton, Tom Conway, Philippe Ciais

Atmospheric accumulation = FFoss + FLUC + FLandAir + FOceanAir

CO2 emissionsfrom fossil fuels

D3 = least developed nationsD2 = other developing nationsIndiaChinaRussia + other FSUD1 = other developed nationsJapanEuropeUSA

1/6

2/3

1/6

Fossil-fuel emissions [MtC/y]

0

1000

2000

3000

4000

5000

6000

7000

8000

1970

1973

1976

1979

1982

1985

1988

1991

1994

1997

2000

2003

D3D2IndiaChinaFSUD1JapanEUUSA

Fossil-fuel emissions (MtC/y)

Unpublished data: please do not cite or quote without permission

Fossil-fuel CO2 emissions in 2005:• 7.9 PgC

Growth rate in fossil-fuel CO2 emissions:• 1990 to 1999: 0.8% per year• 2000 to 2005: 3.2% per year

The emissions story from current data


Drivers of emissions (global)

Kaya Identity World

0.50.60.70.80.9

11.11.21.31.41.5

1980 1985 1990 1995 2000 2005

F (emissions)P (population)g = G/Ph = F/G

GG

P FFP

= × ×

Fossil-fuel emission

Population

Per-capita GDP

Fossil-fuel intensity of GDP


Drivers of emissions (regional)

2003 emissions:• USA: 23%• D2: 19%• China: 16%• Europe:15%• Others: 27%

USA

00.20.40.60.8

11.21.41.61.8

2

1980 1985 1990 1995 2000 2005


GG

P FFP

= × ×

China

00.20.40.60.8

11.21.41.61.8

2

1980 1985 1990 1995 2000 2005



Who contributes to fossil-fuel carbon?Depends on whether we look at stock, flux or growth rate

2003

0%

20%

40%

60%

80%

100%

Stock Flux Growth

D3D2IndiaChinaFSUD1JapanEUUSA

1/6

1/6

2/3

D3 = least developedD2 = other developingIndiaChinaRussia + other FSUD1 = other developedJapanEuropeUSA


Signs of Trouble




Response


Systems approach

Emissions gapEmissions scenario (eg SRES A1B): storyline for global developmentStabilisation trajectory: emissions consistent with stabilision at given CO2

0

2

4

6

8

10

12

14

16

18

1850 1900 1950 2000 2050 2100

Foss

il Fu

el E

mis

sion

(GtC

/y

historic emissionsprojected emissions (A1B)to stabilise at 450 ppmto stabilise at 650 ppm

emissions gap

1980 2000 2020


Inertia in carbon-climate-human interactionsComponents

Recognition of climate change

Negotiation of agreements

Deploying technologies

Land and ocean system inertia

Implication

Start now (or sooner)

Vulnerability of carbon pools

C4MIP = Coupled Climate Carbon Cycle Model Intercomparison Expt(Friedlingstein et al. 2006)

Intercomparison of 11 coupled climate-carbon cycle models

For all models, feedbacks =>• increased CO2• more warming (by 0.1-1.5 deg)• higher AF (by 0.02-0.22)

Main carbon-climate feedbacks:• ocean CO2 uptake• CO2 fertilisation of land NPP• climate effects on carbon

release from land pools

NOW

Vulnerable C pools (not in C4MIP) => additional 100 to >200 ppm CO2 (Gruber et al. 2004)

Vulnerability of carbon pools

The response of the global carbon cycle:the airborne fraction of anthropogenic CO2

AF = (Atmospheric accumulation) / (Emissions from fossil fuels + LUC)AF fluctuates greatly through climate variability (ENSO) and volcanoesSmoothed AF has been nearly steady (0.4 to 0.5) for over 100 yearsAF will increase over decades because of carbon-climate vulnerability

AF

1900 1950 2000 2050 2100

0.2

0.4

0.6

0.8

1

?

?C4MIP

Extra vulnerabilities


Estimating the cap on cumulative emissions with AF

Find the cumulative release of anthropogenic C up to stabilisation

Numbers:• Cumulative C release from 2000 (to 550 ppm): < 750 GtC• Anthropogenic C release from 1750 to present: ~ 480 GtC• Anthropogenic C release 2000-2100 (for A1B): ~ 1200 GtC

Future anthropogenic C release is a finite, non-renewable resource

( ) ( )stab nowCumulative anthropogenic C release

average AFA AC C−

=


Signs of Trouble




Response


Systems approach

1. Technical: many options

Broad portfolio:• Non fossil-fuel energy (renewables ...)• Cleaner fossil fuel energy• Conservation

Both supply-side and demand-side focus

A systems approach to meet multiple criteria (greenhouse, economic, social, other environmental ...)

2. Economic: solutions we can afford

3. Policy: cap, price signal

0

2

4

6

8

10

12

14

16

18

1850 1900 1950 2000 2050 2100

Foss

il Fu

el E

mis

sion

(GtC

/y

historic emissionsprojected emissions (A1B)to stabilise at 450 ppmto stabilise at 650 ppm

emissions gap

• The policy challenges:• Global emissions cap (with equity)• Carbon price signal (with equity)


SummaryPresent signs of trouble in carbon-climate-human interactions

• Fossil-fuel emissions have accelerated since Y2000• Current emissions exceed stabilisation trajectories• Airborne fraction of CO2 emissions (AF) is presently holding at 0.45

Signs of trouble in the future• Inertia: recognition, agreements, technologies, land-ocean systems• The emissions gap is increasing• Vulnerability: land and ocean carbon pools

human responses (failure to protect commons)

Responses: four critical dimensions• Technical, economic, policy• Cultural

Culture and ethics in the carbon cycle

Our ethical imperatives:• protect global commons• use finite resources wisely• separate quality of life

from consumption

We are starstuffbillion-year-old carbon

We are goldencaught in the devil's bargain

And we got to get ourselves back to the garden

(Joni Mitchell, Woodstock)

carbon in the earth system: dynamics and vulnerabilities · the response of the global carbon...

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