Audit of the global carbon budget: estimate errors and their impact on uptake uncertainty
Author:
Ballantyne A. P., Andres R., Houghton R.ORCID, Stocker B. D.ORCID, Wanninkhof R., Anderegg W., Cooper L. A., DeGrandpre M., Tans P. P., Miller J. C.ORCID, Alden C., White J. W. C.
Abstract
Abstract. Over the last 5 decades monitoring systems have been developed to detect changes in the accumulation of C in the atmosphere, ocean, and land; however, our ability to detect changes in the behavior of the global C cycle is still hindered by measurement and estimate errors. Here we present a rigorous and flexible framework for assessing the temporal and spatial components of estimate error and their impact on uncertainty in net C uptake by the biosphere. We present a novel approach for incorporating temporally correlated random error into the error structure of emission estimates. Based on this approach, we conclude that the 2 σ error of the atmospheric growth rate has decreased from 1.2 Pg C yr−1 in the 1960s to 0.3 Pg C yr−1 in the 2000s, leading to a ~20% reduction in the over-all uncertainty of net global C uptake by the biosphere. While fossil fuel emissions have increased by a factor of 4 over the last 5 decades, 2 σ errors in fossil fuel emissions due to national reporting errors and differences in energy reporting practices have increased from 0.3 Pg C yr−1 in the 1960s to almost 1.0 Pg C yr−1 during the 2000s. At the same time land use emissions have declined slightly over the last 5 decades, but their relative errors remain high. Notably, errors associated with fossil fuel emissions have come to dominate uncertainty in the global C budget and are now comparable to the total emissions from land use, thus efforts to reduce errors in fossil fuel emissions are necessary. Given all the major sources of error in the global C budget that we could identify, we are 93% confident that C uptake has increased and 97% confident that C uptake by the terrestrial biosphere has increased over the last 5 decades. Although the persistence of future C sinks remains unknown and some ecosystem services may be compromised by this continued C uptake (e.g. ocean acidification), it is clear that arguably the greatest ecosystem service currently provided by the biosphere is the continued removal of approximately half of atmospheric CO2 emissions from the atmosphere.
Publisher
Copernicus GmbH
Reference56 articles.
1. Ainsworth, E. A. and Long, S. P.: What have we learned from 15 years of free-air CO2 enrichment (FACE)? A meta-analytic review of the responses of photosynthesis, canopy properties and plant production to rising CO2, New Phytol., 165, 351–372, 2005. 2. Andres, R. J., Boden, T. A., Bréon, F.-M., Ciais, P., Davis, S., Erickson, D., Gregg, J. S., Jacobson, A., Marland, G., Miller, J., Oda, T., Olivier, J. G. J., Raupach, M. R., Rayner, P., and Treanton, K.: A synthesis of carbon dioxide emissions from fossil-fuel combustion, Biogeosciences, 9, 1845–1871, https://doi.org/10.5194/bg-9-1845-2012, 2012. 3. Andres, R. J., Boden, T., and Higdon, D.: A new evaluation of the uncertainty associated with CDIAC estimates of fossil fuel carbon dioxide emission, Tellus B, 66, 23616, https://doi.org/10.3402/tellusb.v66.23616, 2014. 4. Andrews, J. A. and Schlesinger, W. H.: Soil CO2 dynamics, acidification, and chemical weathering in a temperate forest with experimental CO2 enrichment, Global Biogeochem. Cy., 15, 149–162, 2001. 5. Bakker, D., Hankin, S., Olsen, A., Pfeil, B., Smith, K., Alin, S., Cosca, C., Hales, B., Harasawa, S., and Kozyr, A.: An Update to the Surface Ocean CO2 Atlas (SOCAT Version 2): Earth, 2014.
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