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RECCAP Overview

Overview paper

Canadell JG, Ciais P, Gurney K, Le Quéré C, Piao S, Raupach MR, Sabine CL (2011)
An international effort to quantify regional carbon fluxes (pdf, 794kb) EOS 92: 81-82.


  • To establish the mean carbon balance of large regions of the globe at the scale of continents and large ocean basins, including their component fluxes.
  • To do it by using and comparing bottom-up estimates with the results of regional top-down atmospheric inversions, and thereby test the compatibility of regional bottom-up estimates with global atmospheric constraints.
  • To evaluate the regional ‘hot-spots’ of interannual variability and possibly the trends and underlying processes over the past two decades by combining available long-term observations and modeling.


  • To provide higher spatial resolution of the global carbon balance with the aim to improve attribution to processes and identify hot-spots regions essential to understand its future evolution.
  • To address a growing demand for a capacity to Measure, Report, and Verify (MRV) the evolution of regional fluxes and the outcomes of climate mitigation policies.
  • To support capacity building in regions with regional carbon balances of significant global influence but with little or not technical capabilities.
  • To respond to the Group on Earth Observations (EOS) in establishing a global carbon observatory to track the evolution of natural and anthropogenic carbon sources and sinks.

How we expect to achieve it?

  • Through a large global coordination effort.
  • The development of a “soft protocol” to guide and ensure consistency among regional synthesis (so they can be compared and add up at the end).
  • Relying primarily on:
    • existing analyses,
    • regional and national programs (eg, North American Carbon Synthesis, CarboEurope, China and East Asia budgets, Australian NCAS, LBA),
    • global modeling and synthesis efforts (eg. GCP annual global budget, GCP-TRENDY, TRANSCOM).
  • Relying secondarily on:
    • the establishment of new synthesis teams in regions where there is not an established carbon program with the support of active regions.


  1. Special issue (and possibly published also as a book), including papers on regional land and ocean C budgets, papers assessing overall state, trends and variability in carbon fluxes, and synthesis papers testing compatibility of regional bottom-up estimates with global atmospheric constraints (pdfs should be available shortly after publication for wide distribution). We will explore Online Open Access journals to ensure that publication after submission of individual papers is not delayed by late submissions. Examples of Journals that will be explored are Biogeosciences and Earth Interactions. Suggestions are welcome.
  2. High-level synthesis paper/s reporting key results in Science, Nature or Nature-Geoscience. Possibility for 2-3 high-level synthesis papers as special feature in Nature-Geosciences.
  3. Summary for Policy Makers and wider audiences.
  4. Database (updatable in the future) of C fluxes from regional and global estimates

RECCAP Approach

RECCAP's Approach


Global and Regional Syntheses


A group of scientists will take responsibility for assembling a synthesis of the C balance of their region, using an ensemble of methods and data. This synthesis should broadly follow the IPCC principles:

  • draw mostly on existing research work and tools, although specific new data analysis or model simulations will be welcome,
  • give a fair account of representative results obtained by different groups which can be reflected in the multiple authorship of the synthesis,
  • provide traceable and referenced information about the data and model sources,
  • provide a clear assessment of uncertainties and methods, including remaining areas of discrepancy, or uncharted areas. We do not expect an even distribution of knowledge and uncertainties over each region of the globe, given the contrasting density of regional C observation networks.

Guidelines for synthesis scope, content and lengths

No more than 15 pages of text double spaced + additional figures and references. The text should consist of synthesis work for a general scientific readership, summarizing the various existing streams of data or model results, and focusing on analyzing the results and their uncertainties (length and formats will change based on the election of journals)

Global Syntheses G1-G5

Each of these syntheses will cover and analyze the globe subdivided into large regions (e.g. the TRANSCOM land and ocean regions) using a globally homogeneous approach global analysis of fossil fuel and cement emissions from harmonized energy-related statistics. Synthesis work in each of these ‘global’ syntheses should begin with a summary description of the approach and data used, focus primarily on discussing regional differences in C balance and uncertainties, possibly in light of the underlying mechanisms. Each region will be analyzed both for its long term mean C budget over the target period 1990-2008, but also wherever possible for their rate of interannual variability and trends. Regions poorly constrained by data should be identified

Regional Land Syntheses (L1-L11)

Each regional land syntheses should at least provide:

  • Estimate of the long-term mean C budget, over the past 18 years (1990-208) excluding anthropogenic emissions that will be treated in a separate synthesis.
  • Provide estimate of the average (monthly) seasonal cycle of ecosystem fluxes and (if possible) of disturbance-related emissions.
  • Provide a simple breakdown, e.g. in a summary table, of the long term mean C budget into component gross fluxes of GPP, NPP, RH, and Disturbance emissions for major land cover types including at least croplands, grassland and forests (themselves possibly separated if necessary into types such as deciduous vs. conifers).
  • Provide estimation of the interannual flux anomalies over the past 16 years
  • Give an overview of the dominant underlying processes causing sources and sinks and, if relevant, of sub-regional ‘hot spots’.

Regional Ocean Syntheses O1-O7

Each regional ocean synthesis should at least provide:

  • Estimate of the long-term mean C budget, over the past 18 years (1990-2008), including interior ocean.
  • Provide an estimate of the natural and anthropogenic CO2 fluxes
  • Provide estimate of the average (monthly) seasonal cycle of CO2 fluxes
  • Provide a simple breakdown, e.g. in a summary table, of the long term mean C budget into component gross fluxes of primary production, export production, thermal component and physical transport.
  • Provide estimation of the interannual flux anomalies since 1983.
  • Give an overview of the dominant underlying processes causing sources and sinks and, if relevant, of sub-regional ‘hot spots’.

Final Syntheses S1-6

These Synthesis Of Synthesis (= S syntheses) will be drafted during the meeting, drawing upon the results of syntheses above. To facilitate this process, a spreadsheet with the main regional results from these chapters will be prepared and distributed short before the meeting. Four SOS chapters are foreseen that will integrate top-down inversions results with state of the art bottom-up long-term mean fluxes, and their interannual variability, possibly also in key regions the long term trends. Areas where both approaches converge or differ will be identified, as well as uncertainties assessed into a coherent framework. A discussion of the different processes contributing regionally (eg CO2 fertilization versus legacy from past land use change and climate change) will be provided in synthesis S3. Finally, synthesis S4 will make essential recommendations for reducing errors in the future (e.g. organizing data exchange protocols, tailored model intercomparisons or model-data comparison, identify regions where key information is missing and ways to reduce uncertainties in a 5-10 years time frame, including the forthcoming advent of remotely sensed CO2 columns from new sensors).


A list of presentations from several meetings (overview and progress).