Historic global biomass burning emissions for CMIP6 (BB4CMIP) based on merging satellite observations with proxies and fire models (1750–2015)
Margreet J. E. van Marle1,a,Silvia Kloster2,Brian I. Magi3,Jennifer R. Marlon4,Anne-Laure Daniau5,Robert D. Field6,Almut Arneth7,Matthew Forrest8,Stijn Hantson7,Natalie M. Kehrwald9,Wolfgang Knorr10,Gitta Lasslop2,Fang Li11,Stéphane Mangeon12,Chao Yue13,Johannes W. Kaiser14,and Guido R. van der Werf1Margreet J. E. van Marle et al.Margreet J. E. van Marle1,a,Silvia Kloster2,Brian I. Magi3,Jennifer R. Marlon4,Anne-Laure Daniau5,Robert D. Field6,Almut Arneth7,Matthew Forrest8,Stijn Hantson7,Natalie M. Kehrwald9,Wolfgang Knorr10,Gitta Lasslop2,Fang Li11,Stéphane Mangeon12,Chao Yue13,Johannes W. Kaiser14,and Guido R. van der Werf1
Received: 03 Feb 2017 – Discussion started: 08 Feb 2017 – Revised: 12 Jun 2017 – Accepted: 30 Jun 2017 – Published: 11 Sep 2017
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 Pg C 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.
Fire emission estimates are a key input dataset for climate models. We have merged satellite information with proxy datasets and fire models to reconstruct fire emissions since 1750 AD. Our dataset indicates that, on a global scale, fire emissions were relatively constant over time. Since roughly 1950, declining emissions from savannas were approximately balanced by increased emissions from tropical deforestation zones.
Fire emission estimates are a key input dataset for climate models. We have merged satellite...
