Large historical growth in global terrestrial gross primary production

• Published in: Nature
• Main Authors: CAMPBELL, J. E., BERRY, J. A., SEIBT, U., SMITH, S. J., MONTZKA, S. A., LAUNOIS, Thomas, BELVISO, Sauveur, BOPP, Laurent, LAINE, M.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Nature Publishing Group 2017
• Subjects: photosynthèse foliaire; teneur en dioxyde de carbone; production primaire brute; Sciences du Vivant [q-bio]; ice core
• Online Access: https://oskar-bordeaux.fr/handle/20.500.12278/196587; https://hdl.handle.net/20.500.12278/196587; https://doi.org/10.1038/nature22030

Growth in terrestrial gross primary production (GPP)-the amount of carbon dioxide that is 'fixed' into organic material through the photosynthesis of land plants-may provide a negative feedback for climate change. It remains uncertain, however, to what extent biogeochemical processes can suppress global GPP growth. As a consequence, modelling estimates of terrestrial carbon storage, and of feedbacks between the carbon cycle and climate, remain poorly constrained. Here we present a global, measurement-based estimate of GPP growth during the twentieth century that is based on long-term atmospheric carbonyl sulfide (COS) records, derived from ice-core, firn and ambient air samples. We interpret these records using a model that simulates changes in COS concentration according to changes in its sources and sinks-including a large sink that is related to GPP. We find that the observation-based COS record is most consistent with simulations of climate and the carbon cycle that assume large GPP growth during the twentieth century (31% ± 5% growth; mean ± 95% confidence interval). Although this COS analysis does not directly constrain models of future GPP growth, it does provide a global-scale benchmark for historical carbon-cycle simulations. Coordinated Research in Earth Systems and Climate: Experiments, kNowledge, Dissemination and Outreach Carbonic anhydrase: where the CO2, COS and H2O cycles meet