Abstract
Fires have influenced atmospheric composition and climate since the rise of vascular plants, and satellite data have shown the overall global extent of fires. Our knowledge of historic fire emissions has progressively improved over the past decades due mostly to the development of new proxies and the improvement of fire models. Currently, there is a suite of proxies including sedimentary charcoal records, measurements of fire-emitted trace gases and black carbon stored in ice and firn, and visibility observations. These proxies provide opportunities to extrapolate emission estimates back in time based on satellite data starting in 1997, but each proxy has strengths and weaknesses regarding, for example, the spatial and temporal extents over which they are representative. We developed a new historic biomass burning emissions dataset starting in 1750 that merges the satellite record with several existing proxies and uses the average of six models from the Fire Model Intercomparison Project (FireMIP) protocol to estimate emissions when the available proxies had limited coverage. According to our approach, global biomass burning emissions were relatively constant, with 10-year averages varying between 1.8 and 2.3 PgC yr-1. Carbon emissions increased only slightly over the full time period and peaked during the 1990s after which they decreased gradually. There is substantial uncertainty in these estimates, and patterns varied depending on choices regarding data representation, especially on regional scales. The observed pattern in fire carbon emissions is for a large part driven by African fires, which accounted for 58% of global fire carbon emissions. African fire emissions declined since about 1950 due to conversion of savanna to cropland, and this decrease is partially compensated for by increasing emissions in deforestation zones of South America and Asia. These global fire emission estimates are mostly suited for global analyses and will be used in the Coupled Model Intercomparison Project Phase 6 (CMIP6) simulations.
Original language | English |
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Pages (from-to) | 3329-3357 |
Number of pages | 29 |
Journal | Geoscientific Model Development |
Volume | 10 |
Issue number | 9 |
DOIs | |
Publication status | Published - 11 Sept 2017 |
Funding
Acknowledgements. We would like to thank Kees Klein Goldewijk, Benjamin Aouizerats, Niels Andela, Pierre Friedlingstein, and Thijs van Leeuwen for their help and useful discussions. This work was initiated by Claire Granier, Steven Smith, the CMIP community, and the Interdisciplinary Biomass Burning Initiative (IBBI). Furthermore, we acknowledge the PAGES Global Paleofire Working Group for making the Global Charcoal Database publicly available and supporting fire workshops. Margreet J. E. van Marle and Guido R. van der Werf were supported by the ERC (grant no. 280061). NSF award BCS-1437074 and BCS-1436496 provided workshop support and funding for Jennifer R. Marlon and Brian I. Magi. PICS CNRS 06484 provided workshop support for ALD. Robert D. Field was supported by the NASA Atmospheric Chemistry Modeling and Analysis Program. Stijn Hantson and Almut Arneth acknowledge support by the EU FP7 projects BACCHUS (grant no. 603445) and LUC4C (grant no. 603542). Johannes W. Kaiser was supported by the EU H2020 project MACC-III (grant no. 633080). Wolfgang Knorr acknowledges the support of PEGASOS (EU contract 265148) and BECC (Biodiversity and Ecosystem services in a Changing Climate, funded by the Swedish Government). We thank three anonymous reviewers for their constructive comments and helpful suggestions on an earlier version of the manuscript.
Funders | Funder number |
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Biodiversity and Ecosystem services in a Changing Climate | |
EU FP7 | 603542, 603445 |
EU H2020 | 265148, 633080 |
National Aeronautics and Space Administration | |
European Research Council | BCS-1437074, BCS-1436496, 280061 |