Global CarbonObservatory

Pep CanadellGCP-CSIRO Marine and Atmospheric Research

With contributions and thanks to:Philippe Ciais, David Crisp, Roger Dargaville,

Stephen Plummer, Michael Raupach

Integrated Global Carbon Observations - IGCO

Outline

1. Goals and Vision for a global C observatory

2. Major types of observations3. Satellite observations

• Carbon from space: OCO, GOSAT4. In situ observations5. Process understanding

• Linking observations to processes• Fundamental research and model development

1. Goals and Vision of a Carbon Observatory• To provide the long-term observations required to improve understanding of the present state and future behavior of the global carbon cycle, particularly the factors that control the global atmospheric CO2 level and feedbacks to climate.

• To measure carbon sources and sinks from global to regional scales in a way that can inform the development of international climate treaties, and methodologies for national GHGs budgets and domestic policies.

• To monitor and assess the effectiveness of carbon sequestration and/or emission reduction activities on global atmospheric CO2levels, including attribution of sources and sinks by region andsector.

IGCO 2004, GCP 2003

Vision for a Carbon Cycle Model-Data Assimilation System

Ocean remote sensingOcean colourAltimetryWindsSSTSSS

Ocean remote sensingOcean colourAltimetryWindsSSTSSS

Ocean time seriesBiogeochemical

pCO2

Surface observationpCO2

nutrients

Water columninventories

Remote sensing ofVegetation propertiesGrowth CycleFiresBiomassRadiationLand cover /use

Remote sensing ofVegetation propertiesGrowth CycleFiresBiomassRadiationLand cover /use

Ecologicalstudies

Ecologicalstudies

Biomasssoil carboninventories

Eddy-covarianceflux towers

Remote sensing ofAtmospheric CO2

Atmosphericmeasurements

Georeferenceemissions inventories Data

assimilationlink

Climate and weatherfields

Terrestrialcarbonmodel

Terrestrialcarbonmodel

AtmosphericTransport model

AtmosphericTransport model

Oceancarbon model

Oceancarbon model

optimizedfluxes

optimizedmodel

parameters

Lateral fluxesCoastalstudies

Rivers

IGCO 2004

Multiple Constraints Data Assimilation for Carbon Cycle1980-2000

Mean Net Flux to the Atmosphere (gC m-2 y-1)Continental to Sub-continental Resolution

Data Assimilated:• Atmospheric [CO2 ]• AVHRR - PAR

• 12 Functional Veg. Types

Models:• atmospheric

transport model• terrestrial

biosphere (BETHY)

Rayner et al. 2005

TransCom resolution• Transport Model• Atmospheric CO2

2. Types of Observations

Complementary core groups of observations to address three themes:

• Fluxes: observations to enable quantification of the distribution and variability of the CO2 fluxes between the Earth’s surface and the atmosphere.

• Pools: Observations on changes in the atmospheric, oceanic, and terrestrial reservoir carbon pools.

• Process: Measurements related to the important carbon cycle processes that control fluxes.

Atmospheric column CO2 concentrationmeasured from satellites

Atmospheric CO2concentration measured from in situ networks

Land-atmosphere CO2 flux measured via eddy covariance flux network

Global, synoptic satellite observations to extrapolate in situ data

Fluxes

Forest biomassinventories

Soil carboninventories

Carbon storage in the sediments of reservoirs, lakes

Carbon storage in anthropogenic pools, primarily wood products

PoolsIGCO 2004

Basin-scale observations of the air-sea flux (ocean pCO2) from ship-based measurements, drifters and time series

Global, synoptic satellite observations to extrapolate in situ dataWinds, SST, SSS, ocean colour

Fluxes

Sediment trap and sea-floor studies, with a special emphasis on coastal sediments

Basin-scale ocean inventories with full column sampling of carbon system parameters

PoolsIGCO 2004

3. Priorities for Satellite Observations

• Column-integrated atmospheric CO2• Atmospheric CO2 and aerosols• Biomass burning CH4 emissions• Column integrated CH4

• Atmospheric structure, temperature, humidity, winds.

• Land-cover change• Ecosystem disturbances• Directional reflectance• Ocean color• Ancillary terrestrial data• Ancillary oceanic data• Forest aboveground biomass• Wetland coverage

New Measurements

Not new but require new spatial and temporal resolution, orbetter coordination

IGCO 2004

CO2 from Space: Instruments

Instrument Coverage Weight-func Hrl Res CO CH4 CO2 Precision

TOVS trop monthly upper-trop 15 degs no no yes —SCIAMACHY global column 30×60 km yes yes yes 3-5ppmAIRS glob daily mid-trop 50 km yes yes yes 2ppmIASI glob daily mid-trop 50 km yes yes yes 2ppmCRIS glob daily mid-trop 50 km yes yes yes 2ppmOCO sunlit column 1 km no no yes 1–2ppmGOSAT sunlit column — — yes yes 1–2ppmACCLAIM glob weekly lower trop 100m no no yes 1ppmA-SCOPE glob weekly lower trop 100m no no yes 1ppm

Peter Rayner 2005 (unpublished)

The Orbiting Carbon Observatory (OCO)

• Resolve pole to pole XCO2gradients on regional scales

• Resolve the XCO2 seasonal cycle • Improve constraints on CO2

fluxes (sources and sinks) compared to the current knowledge:– Reduce regional scale flux

uncertainties from >2000 gCm-2 yr-1 to < 200 gC m-2 yr-1

– Reduce continental scale flux uncertainties below 30 gC m-2

yr-1David Chris 2005

Near Infrared Passive SensorLaunched in 2007

OCO Path: 1-day Unselected

OCO Path: Clouds Selected

OCO Path: 3-day Unselected

Uncertainy Reduction from Different Data Sources

Houweling et al. 2005

CO2 Inversions

2 weekly

Data

4. Priorities for in situ observations

• Atmospheric CO2 and Carbon Cycle Tracer Observations.

• Eddy Covariance fluxes of CO2, H2O and Energy.

• Large scale biomass inventories.

• Large scale soil carbon inventories.

• Ocean carbonates.

IGCO 2004

Priority Pools and Processes

PermafrostHL PeatlandsT PeatlandsVeg.-Fire/LUC

CH4 HydratesBiological PumpSolubility Pump

Carbon-Climate Feedbacks Hot Spots

Oceans

Land

GCP 2005

Priority Pools and Processes

PermafrostHL PeatlandsT PeatlandsVeg.-Fire/LUC

CH4 HydratesBiological PumpSolubility Pump

Carbon-Climate Feedbacks Hot Spots

Oceans

Land

GCP 2005

Carbon-Climate Feedbacks10 GCMs with coupled carbon cycle

Coupled Climate-Carbon Difference Coupled-Uncoupled

Atmo

sphe

ric C

O 2(p

pm)

220 ppm

NO processes on thawing frozen carbonNO processes on drained peatlandsNO specific fire processesNO processes accounting for nutrient limitation (N, P)

Friedlingstein et al. 2006

5. Attributing Major Processes to Fluxes

Core space based observationLand-cover changeDisturbances (e.g., fire counts and burned areas)Leaf Area Index and related biophysical processesOcean color (which relates to biological activity)

In situ observation related to processesSoil characteristicsWater vapor and energy eddy covariance fluxesPhenology of the terrestrial biosphereNutrient distributions and fluxes (ocean and land)Species composition of ecosystemsAtmospheric tracers (O2:N2 ; 13C-CO2 ; CO ; aerosols).

Carbon Emissions from FiresAtmospheric Tracers: CO, CH4Remote Sensing: Fire Spots, Burned Area

C Flux Anomalies (gC/m2/yr)El Nino 1997-98

Fire C Emissions Anomaly (gC/m2/yr)El Nino 1997-98

1997-982.1 Pg C emissions from fires

66% of the CO2 growth rate anomaly1997-2001

3.53 Pg C emissions from firesRodenbeck et al. 2003; Werf et al. 2004

Fundamental process understanding & model developmentMore Data is not Enough

(17) Transport Models (TransCom)

4 ppm

Global Terrestrial Carbon Uptake

(6) Dynamic Global Vegetation Models

7 PgCyr-1

Cramer et al. 2001

Biospheric Carbon Uptake (Pg C yr-1)10 GCMs with coupled carbon cycle

Land

Upta

ke (G

t C/yr

)

Land C Uptake Ocean C Uptake

15 Pg7 Pg

Friedlingstein et al. 2006

Candidate Mechanisms of Current Terrestrial Sinks

1. CO2 fertilization2. Nitrogen fertilization3. Warming and preciptation change4. Regrowth in abandoned croplands5. Fire suppression (woody encroach.)6. Regrowth in previously disturbed forests

– Logging, fire, wind, insects7. Decreased deforestation8. Improved agriculture9. Sediment burial10. Carbon Management (reforestation)

Driven byAtmospheric &Climate change

Driven by Land UseChange

Canadell et al. 2006

Attribution of the terrestrial carbon sink

The Terrestrial Carbon Sink…… will increase in the future if the important mechanisms are physiological

(eg, CO2 Fertilization)

…will decrease in the future if the important mechanism are due to the legacy of past land use (eg, regrowth, thickening..)

Climate warms as predictedClimate warms more rapidly than predicted

Sin

k st

reng

th

Sin

k st

reng

th

TerrestrialCarbonObservations

Approach

RS [CO2]RS Measurements[CO2] MeasuremtsBiomass/NPP and

soil inventories

Regional campaignsField experiments

Disturbances

Eddy Covariance fluxes

Plot studies andexperiments

RegionLandscape

1 km2

1 ha

ContinentBiome

Scale

Modified from GTOS, Cihlar et al. 2001

Process studiesPools

and F

luxes

End