Systematic Terrestrial
Observations:
a Case for Carbon
René Gommes
with C. He, J. Hielkema, P. Reichert and J. Tschirley
FAO/SDRN
Overview
•
•
•
•
The context: IGOS and GTOS, and
the objective of TCI
The terrestrial Carbon cycle
Methodological issues: relevance of
satellites, data requirements, scaling
Looking ahead...
The IGOS Partnership
•
•
•
Established in 1998
Rationale: no single country or Organization
has sufficient expertise or resources to make
the observations needed to understand the
complex processes of global change
Partners : Global observing systems (GTOS,
GCOS, GOOS), International scientific
organisations, National space agencies, UN
agencies.
Global Terrestrial Observing System
(GTOS)
The GTOS mission is to provide policy makers, resource
managers and researchers with access to data they need to
detect, quantify, locate, understand and warn of changes
(especially reductions) in the capacity of terrestrial
ecosystems to support sustainable development
GTOS is a member of IGOS and is strengthening the
linkages between scientists who work at the site or
ecosystem level and those who work with satellite imagery
by developing collaborative demonstration projects such as
on Net Primary Productivity and the Terrestrial Carbon
Initiative
The GTOS hierarchical observing strategy
1. Large-area experiments
2. Long-term research centres
3. Field stations
4. Periodic, unstaffed sample sites
5. Frequent low resolution remote sensing
Terrestrial Carbon Initiative, TCI
An IGOS initiative led by GTOS and GCOS, space
agencies and UN organisations, with the contribution of
IGBP members, to contribute to the implementation of
Kyoto Protocol and improve understanding of terrestrial
Carbon cycle by…
• assessing the key information requirements
• co-ordinating efforts aimed at systematically collecting
relevant data and information
• identifying data gaps
• promoting collaboration among the IGOS partners
Objective of TCI
• Demonstrate feasibility of continuous
monitoring of spatial and temporal
variations of terrestrial carbon cycle by
2004 with near-km resolution and good
accuracy
• Improve on required models and
observations (site location, sensors,
variables...)
Overview
• The context: IGOS and GTOS, and the
objective of TCI
• The terrestrial Carbon cycle
• Methodological issues: relevance of
satellites, data requirements, scaling
• Looking ahead...
Terrestrial carbon balance
NBP
GtC/year
Net primary production potential
0.5 degree resolution
Source: FAO/SDRN,
based on IIASA Climate Database and the “Miami model” (1972)
Soil Carbon Content
Source: FAO/AGLS, W.Sombroek, F.Nachtergaele and A.Hebel, 1993
Soil carbon fluxes
gC year-1 m-2
Source: J.Raich and C.Potter, 1995
Continental South Asia
above-ground biomass density
Po net d
Biom as s de ns ity (T /Ha )
0 - 10
10 - 20
20 - 40
40 - 60
60 - 80
80 - 100
100 - 15 0
150 - 20 0
200 - 25 0
250 - 30 0
300 - 40 0
Source: FAO/
Forest
Resources
Assessment
Net Primary Production potential
(East Lake Victoria, 1km res.)
Source: FAO/SDRN; “Miami model” and FAOCLIM spatialized with SPOT/VEGETATION
Overview
• The context: IGOS and GTOS, and the
objective of TCI
• The terrestrial Carbon cycle
• Methodological issues: relevance of
satellites, data requirements, scaling
• Looking ahead...
Relevance of continuous satellite
and ground observations
• Vegetation, land use and soils undergo
seasonal and long-term changes, some
of which are man-made
• Model calibration more accurate with
continuous data
• Stratification of ground samples and
area averaging
1982-93 Inter-annual variability
of Vegetation Index
Source: FAO/SDRN based on NOAA/NDVI imagery
Need for improvements
• Database of land cover and changes,
losses (fire)
• Estimates of carbon pools and fluxes
• Coupled carbon circulation and biomass
models (ground and satellite inputs:
LAI, solar radiation, water balance…)
• Improved capacity for ground
observations
Problems to be solved
• Geo-referenciation of ground databases
• Integration of biomass, ecosystem and
global atmospheric carbon models
• Scale conversions (pixel to country): upscaling and downscaling
Scaling down: increasing
spatial resolution
Low ( < 15 tons/ha)
Med. (15 - 35 tons/ha)
High ( > 35 tons/ha)
Source:
FAO Forest
Resources
Assessment
Scaling up: natural
forest biomass
Overview
• The context: IGOS and GTOS, and the
objective of TCI
• The terrestrial Carbon cycle
• Methodological issues: relevance of
satellites, data requirements, scaling
• Looking ahead...
Looking ahead...
• By 2008, operational implementation of
the concepts, data collection and
methods will be finalized…
• TCI can improve the quantitative
assessment (mapping and monitoring)
of terrestrial carbon sources and sinks
and contribute towards carbon
accounting
Carbon pools and fluxes