NUMEROUS ACTIVITIES ARE PRESENTLY UNDERWAY OR PLANNED THAT ADDRESS TERRESTRIAL CARBON OBSERVATION IN VARIOUS GEOGRAPHIC REGIONS (SEE CHAPTER 3 AND APPENDIX 2). IN GENERAL, THESE ACTIVITIES CONCERN SPECIFIC OBSERVATION OR RESEARCH ASPECTS AND ARE NOT WELL COORDINATED. THEY ARE ALSO NOT DESIGNED IN A SYSTEMATIC FASHION TO PROVIDE CONSISTENT INFORMATION AT THE GLOBAL SCALE. Thus, while these activities are potentially important building blocks for systematic global carbon observation, there is a need for a focused effort and a common vision to be pursued. The following goals are outlined for the initial terrestrial carbon observing system, with a timetable conditioned by the Kyoto Protocol schedule:
1. By 2005, demonstrate the capability to estimate annual net land-atmosphere fluxes at a sub-continental scale (107 km2) with an accuracy of +/- 30% globally, and at a regional scale (106 km2) over areas selected for specific campaigns with a similar or better accuracy;
2. By 2008, improve the performance to better spatial resolution (106 km2) globally and an accuracy of +/- 20%;
3. In each case, produce flux emission estimate maps with the highest spatial resolution enabled by the available satellite-derived and other input products.
Based on the requirements discussion (Chapter 4 and 5), the resulting carbon observing system should be:
global and long-term in scope, nationally sponsored, and internationally coordinated;
multi-user, needs-driven; and focused, but accommodating to complementary uses (e.g. global hydrological cycle);
based on quality controlled observations and data products, and on full and open exchange of data and information;
adaptable to changing needs and capabilities; and evolving with improving observation instruments, platforms, techniques, and uses (see below);
helping to build capacity on a global basis.
Although the Kyoto Protocol is an important factor in the establishment of global terrestrial carbon observation, the complete range of requirements is considerably more diverse, thus the observing system must respond to the broader set of requirements. The specific reporting requirements for the Kyoto Protocol are under discussion and the result will have implications for the terrestrial carbon observing system. A previous workshop conducted an initial assessment of the potential contributions of satellite observations to various areas of the Kyoto Protocol (Rosenqvist et al., 1999).
The following sections outline an approach to the implementation of the initial observing system.
A successful implementation of a comprehensive terrestrial carbon observing system that assimilates various inputs (see page 6) must necessarily be an evolving process. The most essential elements are listed below, and the main relevant currently existing activities that should be part of the initial observing system are also identified:
Atmospheric sampling for multiple trace gases from in situ and airborne platforms: the GLOBALVIEW-CO2 project and its proposed GLOBALHUBS measurements enhancement (see Long-term continuity, p.19); regional carbon programmes (CARBOEUROPE; Australian Carbon Project; US carbon cycle programme).
Collection of spatial data and imagery needed to apply process models: satellite programmes (see pages 12-20 and Appendix 3).
Estimation of local to global daily carbon fluxes from gridded spatial data using models and scaling algorithms:
Global: the GOFC project, in collaboration with: GTOS NPP project; the World Fire Web project; FAO and UNEP; IGBP projects (GCTE, GAIM, BAHC, IGAC, LUCC);
Regional: regional terrestrial carbon programmes, including: CARBOEUROPE; Australian Carbon Project; LBA; US carbon programme; carbon programmes in Canada, Japan, Russia.
Estimation of global to regional sources and sinks by atmospheric inverse modelling:
Global: IGBP (TransCom);
Regional and national: CARBOEUROPE, LBA/Brazil, the US Carbon Cycle Programme, Australian Carbon Project.
In situ measurements of ecosystem carbon fluxes and pools to provide continuous long term data of carbon and energy exchanges in a range of biomes and quantify inter-annual variability of ecosystem responses to climate, to validate the derived products, and to improve the understanding and models of the processes of carbon exchange: FLUXNET; ILTER; GT-Net; FAO (to access national inventories); regional networks; IGBP networks (SOMNET, FACE).
Atmospheric observing campaigns to allow direct estimation of area-mean carbon fluxes and flux uncertainties over field sites for an evaluation of models and scaling algorithms: regional carbon programmes (see above).
Data analysis, product generation and archiving centres. In the short term, these centres will be located with agencies providing the data and products, representatives of whom are listed above. Their participation will need to be discussed with the individual agencies. A subsequent transition to an ongoing system should be based on lessons learned in the initial period.
An effective data and information handling system (Chapter 5), including some form of reporting and feedback between the individuals and organizations that generate products and services, the users of these products, and the sponsors of the carbon observing system.
An international coordinating office.
To begin the implementation process, an implementation team (IT) should be set up that is linked to the IGCO framework and to existing projects and activities related to TCO. It is proposed that the TCO IT should be a subgroup of the (yet to be defined) IGCO implementation structure, and to place it within the Global Observation of Forest Cover (GOFC) project as the fourth theme (in addition to the existing land cover, fire, and biophysical functioning themes). In 2000, GOFC became a GTOS panel and works closely within that framework by developing networks and capacity to participate in global change studies. The rationale for link within IGCO is obvious. The placing of the TCO IT within GOFC has several advantages: building on the progress of GOFC to date (product definition and development, support of agencies, regional activities and linkages), enhancing GOFC by bringing in the top down component, and ensuring coherent development of the IGOS-P terrestrial carbon observation in the future. With the encouragement of GTOS, the GOFC Scientific and Technical Board (GOFC STB, 2000) has already considered broadening its remit to cover all terrestrial ecosystems; formalizing this expanded scope would be required if TCO were be be undertaken as a theme. Within GOFC, the TCO implementation team would thus have a status that would allow it interact freely with IGCO on technical matters and report directly to GTOS and IGOS-P on programme and policy matters. The TCO terms of reference would be drafted by the lead partner in consultation with other partners, including IGBP, GCOS and others.
To make progress in the implementation of systematic observations of the carbon cycle, the TCO IT should take action at several fronts.
Satellite data and products: the continuity and data product generation issues need to be addressed through discussions and commitments by CEOS members, using SIT as appropriate.
Atmospheric in situ concentration measurements: the IT needs to involve the existing network (GLOBALVIEW-CO2), WMO and national contacts to ensure continuity and to assist in improving these data sets.
Terrestrial in situ measurements: These are considered separately for (i) flux measurements and (ii) other ecosystem observations.
Flux measurements. In the long term, ecosystem flux measurements should become part of operational in situ observing networks (see page 17 and page 21). However, reaching this stage will require further work, primarily technology development to reduce the initial and ongoing costs of operation. Thus, the immediate priority is to ensure continuing operation of the current FLUXNET, presently funded from research budgets. The present IGOS Partners provide the best links to national funding agencies (e.g. CEOS, GCOS through the SBSTA-mandated reporting on national networks, etc.). The improvements in flux networks could thus be pursued by IGOS-P members through concerted (e.g. GTOS/IGBP/GCOS) and individual (within countries) actions. The TCO IT should work through these mechanisms to ensure continuity and further expansion of the flux networks.
Ecosystem observations. The harmonization of existing national or regional ecological observing networks and inventories is a complex task. There is a need for in-depth examination of the issues involved in compiling global (or regional) data sets of in situ observations, by bringing together representatives of networks (global, regional, national) that have been acquiring data needed by TCO. Current efforts (e.g. the North America/Eurasia carbon balance project) should shed light on the best ways to proceed in this area. Further developments in mandated reporting procedures for the Kyoto Protocol will also be important to help clarify the possible mechanisms and most promising avenues for the future.
An agreement on the overall framework for data and products is very important because the ultimate implementation will take place primarily through national agencies (within countries or as a contribution to the international effort). The coordinating roles of international representatives of the national agencies are therefore paramount. Consequently, the TCO IT should involve at least the following IGOS partners:
CEOS, representing space agencies;
WMO, representing atmospheric agencies and associated projects, particularly GLOBALVIEW-CO2;
GTOS and FAO, representing agencies with terrestrial observation interests (regional networks, others);
IGBP and ICSU, representing science agencies.
The TCO IT should also ascertain the need to establish a base year, as an initial stimulus to coordination of data preparation and product generation efforts. Among the candidates are 1990 (reference year for the Kyoto Protocol) and ~2000 (Millennium Ecosystem Assessment).
The effectiveness of an evolving carbon observing system will depend on the mechanisms established to communicate with the sponsors and clients of the system. These will ensure that the system addresses important issues and makes the contributions needed. Given that the implementation will necessarily be distributed, the communication challenge will be very large. The mechanisms employed should not only be sensitive to the changing requirements, but should also provide up-to-date information on existing observation capabilities and products, as well as the performance of the observing system as a whole (IGOS Ad Hoc Working Group on Data and Information Systems and Services, 2000).
In addition to the direct community of product users, it is important to ensure communication with other potential users and the general public. There is also a continuing need to inform the relevant bodies at a national and international level of the importance of a sustained and systematic approach to carbon cycle observations. Equally important is for the general public to be made aware of the benefits of understanding the processes that influence the carbon cycle, and of the need for the global observations. All partners within IGOS have a role in this area, to develop an overall plan, and then keep each other informed of the activities undertaken.