Articles | Volume 11, issue 13
Biogeosciences, 11, 3547–3602, 2014

Special issue: REgional Carbon Cycle Assessment and Processes (RECCAP)

Biogeosciences, 11, 3547–3602, 2014

Reviews and syntheses 03 Jul 2014

Reviews and syntheses | 03 Jul 2014

Current systematic carbon-cycle observations and the need for implementing a policy-relevant carbon observing system

P. Ciais1, A. J. Dolman2, A. Bombelli3, R. Duren4, A. Peregon1, P. J. Rayner5, C. Miller4, N. Gobron6, G. Kinderman7, G. Marland8, N. Gruber9, F. Chevallier1, R. J. Andres10, G. Balsamo11, L. Bopp1, F.-M. Bréon1, G. Broquet1, R. Dargaville5, T. J. Battin12, A. Borges13, H. Bovensmann14, M. Buchwitz14, J. Butler15, J. G. Canadell16, R. B. Cook10, R. DeFries17, R. Engelen11, K. R. Gurney18, C. Heinze21,20,19, M. Heimann22, A. Held23, M. Henry24, B. Law25, S. Luyssaert1, J. Miller26,15, T. Moriyama27, C. Moulin1, R. B. Myneni28, C. Nussli29, M. Obersteiner7, D. Ojima30, Y. Pan31, J.-D. Paris1, S. L. Piao32, B. Poulter1, S. Plummer33, S. Quegan34, P. Raymond35, M. Reichstein22, L. Rivier1, C. Sabine36, D. Schimel37, O. Tarasova38, R. Valentini3, R. Wang1, G. van der Werf2, D. Wickland39, M. Williams40, and C. Zehner41 P. Ciais et al.
  • 1Laboratoire des Sciences du Climat et de l'Environnement, CEA-CNRS-UVSQ, UMR8212, 91191, Gif sur Yvette Cedex, France
  • 2VU University Amsterdam, Amsterdam, the Netherlands
  • 3Euro-Mediterranean Center for Climate Change, CMCC, Division Climate Change Impacts on Agriculture, Forests and Natural Ecosystems; via Augusto Imperatore 16, 73100 Lecce, Italy
  • 4Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Dr, Pasadena, CA 91109, USA
  • 5School of Earth Sciences, University of Melbourne, Australia
  • 6Global Environmental Monitoring Unit, Institute for Environment and Sustainability, European Commission Joint Research Center, Ispra, Italy
  • 7International Institute for Applied Systems Analysis (IIASA), Schlossplatz 1, Laxenburg, Austria
  • 8Research Institute for Environment, Energy, and Economics, Appalachian State University, Boone, NC 28608, USA
  • 9Institute of Biogeochemistry and Pollutant Dynamics and Center for Climate Systems Modeling, ETH Zürich, Zürich, Switzerland
  • 10Carbon Dioxide Information Analysis Center, Oak Ridge National Laboratory, Oak Ridge, TN 37831-6290, USA
  • 11European Centre for Medium-Range Weather Forecast (ECMWF), Shinfield Park, Reading, RG2 9AX, UK
  • 12Department of Limnology, University of Vienna, A-1090 Vienna, Austria
  • 13Chemical Oceanography Unit, University of Liège, Institute de Physique (B5), 4000 Liège, Belgium
  • 14Institute of Environmental Physics (IUP), University of Bremen, Bremen, Germany
  • 15NOAA Earth System Research Laboratory (ESRL), 325, Broadway, Boulder, CO 80305-3337, USA
  • 16CSIRO Marine and Atmospheric Research, Canberra, ACT 2601, Australia
  • 17Department of Geography and Environment, Boston University, Boston, MA 02115, USA
  • 18School of Life Sciences, School of Sustainability, Arizona State University, Tempe, AZ 85287, USA
  • 19Geophysical Institute, University of Bergen, Allégaten 70, 5007 Bergen, Norway
  • 20Bjerknes Centre for Climate Research, Bergen, Norway
  • 21Uni Bjerknes Centre, Uni Research, Bergen, Norway
  • 22Max-Planck-Institute for Biogeochemistry, Jena, Germany
  • 23AusCover Facility, Terrestrial Ecosystem Research Network – TERN, CSIRO, GPO Box 3023, Canberra ACT 2601, Australia
  • 24Forestry Department, Food and Agriculture Organization of the United Nations, Via delle Terme di Caracalla, 00153 Rome, Italy
  • 25Department of Forest Ecosystems and Society, 321 Richardson Hall, Oregon State University, Corvallis, OR 97331, USA
  • 26Cooperative Institute for Research in Environmental Sciences, University of Colorado, Boulder, CO 80309, USA
  • 27Japan Aerospace Exploration Agency (JAXA), Tokyo
  • 28Department of Earth and Environment, Boston University, Boston, MA 02215, USA
  • 29Thales Alenia Space, Toulouse, France
  • 30Natural Resource Ecology Laboratory, Campus Mail 1499, Fort Collins, CO 80523-1499, USA
  • 31US Department of Agriculture Forest Service, Newtown Square, PA 19073, USA
  • 32Department of Ecology, Peking University, Beijing 100871, China
  • 33ESA Climate Office, European Space Agency – Harwell, Didcot, Oxfordshire OX11 0QX, UK
  • 34Centre for Terrestrial Carbon Dynamics, University of Sheffield, Hicks Building, Hounsfield Road, Sheffield S3 7RH, UK
  • 35Yale School of Forestry and Environmental Studies, 195 Prospect Street, New Haven, CT 06511, USA
  • 36Pacific Marine Environmental Laboratory, National Oceanic and Atmospheric Administration, Seattle, WA 98115, USA
  • 37National Ecological Observatory Network, Boulder, CO 80301, USA
  • 38World Meteorological Organization, 7bis Avenue de la Paix, 1211 Geneva, Switzerland
  • 39National Aeronautics and Space Administration, Suite 3B74, 300 E Street SW, Washington, DC 20546, USA
  • 40School of GeoSciences, University of Edinburgh, Edinburgh, EH9 3JN, UK
  • 41ESA/ESRIN, Earth Observation Applications Engineer, Via Galileo Galilei CP, 64, Frascati Italy

Abstract. A globally integrated carbon observation and analysis system is needed to improve the fundamental understanding of the global carbon cycle, to improve our ability to project future changes, and to verify the effectiveness of policies aiming to reduce greenhouse gas emissions and increase carbon sequestration. Building an integrated carbon observation system requires transformational advances from the existing sparse, exploratory framework towards a dense, robust, and sustained system in all components: anthropogenic emissions, the atmosphere, the ocean, and the terrestrial biosphere. The paper is addressed to scientists, policymakers, and funding agencies who need to have a global picture of the current state of the (diverse) carbon observations. We identify the current state of carbon observations, and the needs and notional requirements for a global integrated carbon observation system that can be built in the next decade. A key conclusion is the substantial expansion of the ground-based observation networks required to reach the high spatial resolution for CO2 and CH4 fluxes, and for carbon stocks for addressing policy-relevant objectives, and attributing flux changes to underlying processes in each region. In order to establish flux and stock diagnostics over areas such as the southern oceans, tropical forests, and the Arctic, in situ observations will have to be complemented with remote-sensing measurements. Remote sensing offers the advantage of dense spatial coverage and frequent revisit. A key challenge is to bring remote-sensing measurements to a level of long-term consistency and accuracy so that they can be efficiently combined in models to reduce uncertainties, in synergy with ground-based data. Bringing tight observational constraints on fossil fuel and land use change emissions will be the biggest challenge for deployment of a policy-relevant integrated carbon observation system. This will require in situ and remotely sensed data at much higher resolution and density than currently achieved for natural fluxes, although over a small land area (cities, industrial sites, power plants), as well as the inclusion of fossil fuel CO2 proxy measurements such as radiocarbon in CO2 and carbon-fuel combustion tracers. Additionally, a policy-relevant carbon monitoring system should also provide mechanisms for reconciling regional top-down (atmosphere-based) and bottom-up (surface-based) flux estimates across the range of spatial and temporal scales relevant to mitigation policies. In addition, uncertainties for each observation data-stream should be assessed. The success of the system will rely on long-term commitments to monitoring, on improved international collaboration to fill gaps in the current observations, on sustained efforts to improve access to the different data streams and make databases interoperable, and on the calibration of each component of the system to agreed-upon international scales.

Final-revised paper