Current systematic carbon cycle observations and needs for implementing a policy-relevant carbon observing system
Creators: name: Ciais, Philippe
name: Dolman, A. Johannes
name: Bombelli, Antonio
name: Duren, Riley M.
name: Peregon, Anna M.
name: Rayner, Peter J.
name: Miller, Charles E.
name: Gobron, Nadine
name: Kinderman, G.
name: Marland, Gregg
name: Gruber, Nicolas
name: Chevallier, Frédéric
name: Andres, Robert J.
name: Balsamo, Gianpaolo
name: Bopp, Laurent
name: Bréon, François-Marie
name: Broquet, Grégoire
name: Dargaville, Roger
name: Battin, Tom J.
name: Borges, Alberto Vieira
name: Bovensmann, Heinrich
name: Buchwitz, Michael
name: Butler, James H.
name: Canadell, Josep G.
name: Cook, Robert B.
name: DeFries, Ruth
name: Engelen, Richard
name: Heinze, Christoph
name: Heimann, Martin
name: Held, Alex
name: Henry, Matieu
name: Law, Beverly E.
name: Luyssaert, Sebastiaan
name: Miller, John Bharat
name: Moriyama, Takashi
name: Moulin, Christophe
name: Myneni, Ranga B.
name: Nussli, C.
name: Obersteiner, Michael
name: Ojima, Dennis
name: Pan, Y.
name: Paris, Jean Daniel
name: Piao, Shilonog Long
name: Poulter, Benjamin
name: Plummer, Stephen
name: Quegan, Shaun
name: Raymond, Peter A.
name: Reichstein, Markus
name: Rivier, Leonard
name: Sabine, Christopher L.
name: Schimel, David S.
name: Tarasova, Oksana A.
name: Valentini, Riccardo
name: Wang, Rong
name: van der Werf, Guido R.
name: Wickland, Diane
name: Williams, Mathew
name: Zehner, Claus
Publisher: name: ETH Zurich
Year: 2013

description: 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.
description: Biogeosciences Discussions, 10
description: ISSN:1810-6277
description: ISSN:1810-6285