Global Pyrogenic Carbon Production During Recent Decades Has Created the Potential for a Large, Long‐Term Sink of Atmospheric CO2. Issue 12 (22nd December 2018)

• Record Type: Journal Article
• Authors: Wei, Xinyuan; Hayes, Daniel J.; Fraver, Shawn; Chen, Guangsheng
• Is Part Of: Journal of geophysical research. Volume 123:Issue 12(2018)
• Page Start: 3682
• Page End: 3696
• Publication Date: 2018-12-22
• Subjects: carbon cycle -- carbon dioxide -- carbon sinks -- fires -- pyrogenic carbon; Geobiology -- Periodicals; Biogeochemistry -- Periodicals; Biotic communities -- Periodicals; Geophysics -- Periodicals; 577.14
• DOI: 10.1029/2018JG004490
• Languages: English
• ISSNs: 2169-8953

Abstract

Abstract: Fires play an important role in the terrestrial biosphere carbon cycle, not only through direct carbon release but also contributing to a potential long‐term storage as pyrogenic carbon (PyC). PyC is formed through fires, and, because it may resist further biological and chemical degradation, is more stable in soil and sediment than original biomass. At the global scale, contributions of fires to both atmospheric CO2 emissions and PyC accumulation are potentially large but difficult to estimate. Our analysis was based on existing simulation results from two different modeling approaches (Global Fire Emissions Database version 4 [GFED4s] and Terrestrial Ecosystem Model version 6 [TEM6]) that used global area burned data to provide recent, retrospective estimates of CO2 emissions from vegetation combustion, together with published, biome‐ and continental‐scale conversion ratios that relate CO2 emissions to PyC production (PyC/CO2 ) during combustion. The estimates of global CO2 emissions from fires differed substantially between the two models' results. GFED4s estimated 2, 041 Tg C/year during the 2000–2016 time period, whereas the TEM6 estimate was considerably lower at 643 Tg C/year from 2000 to 2010. Global PyC production estimates from fires were 153.4 ± 18.7 and 49.5 ± 4.9 Tg C/year based on the emission estimates from GFED4s and TEM6, respectively. Our results suggest that African tropical savanna fires produced the largest amount of CO2 emissions and PyC among global biomes, the most significant interannual variations in CO2 emissions and PyC production were found in tropical forests, and the magnitude of PyC produced by fires each year represented a potentially significant long‐term sink of atmospheric CO2 . Key Points: We present two modeling approaches to estimate the spatiotemporal dynamics of global pyrogenic carbon (PyC) produced from fires We calculate global PyC production from fires as 153.4 ± 18.7 and 49.5 ± 4.9 Tg C/year based on the estimates from GFED4s and TEM6 The magnitude of PyC produced by fires represents a potentially significant long‐term sink of atmospheric CO2