Abstract. New burned area datasets and top-down constraints from atmospheric concentration measurements of pyrogenic gases have decreased the large uncertainty in fire emissions estimates. However, significant gaps remain in our understanding of the contribution of deforestation, savanna, forest, agricultural waste, and peat fires to total global fire emissions. Here we used a revised version of the Carnegie-Ames-Stanford-Approach (CASA) biogeochemical model and improved satellite-derived estimates of area burned, fire activity, and plant productivity to calculate fire emissions for the 1997–2009 period on a 0.5° spatial resolution with a monthly time step. For November 2000 onwards, estimates were based on burned area, active fire detections, and plant productivity from the MODerate resolution Imaging Spectroradiometer (MODIS) sensor. For the partitioning we focused on the MODIS era. We used maps of burned area derived from the Tropical Rainfall Measuring Mission (TRMM) Visible and Infrared Scanner (VIRS) and Along-Track Scanning Radiometer (ATSR) active fire data prior to MODIS (1997–2000) and estimates of plant productivity derived from Advanced Very High Resolution Radiometer (AVHRR) observations during the same period. Average global fire carbon emissions according to this version 3 of the Global Fire Emissions Database (GFED3) were 2.0 Pg C year−1 with significant interannual variability during 1997–2001 (2.8 Pg C year−1 in 1998 and 1.6 Pg C year−1 in 2001). Globally, emissions during 2002–2007 were relatively constant (around 2.1 Pg C year−1) before declining in 2008 (1.7 Pg C year−1) and 2009 (1.5 Pg C year−1) partly due to lower deforestation fire emissions in South America and tropical Asia. On a regional basis, emissions were highly variable during 2002–2007 (e.g., boreal Asia, South America, and Indonesia), but these regional differences canceled out at a global level. During the MODIS era (2001–2009), most carbon emissions were from fires in grasslands and savannas (44%) with smaller contributions from tropical deforestation and degradation fires (20%), woodland fires (mostly confined to the tropics, 16%), forest fires (mostly in the extratropics, 15%), agricultural waste burning (3%), and tropical peat fires (3%). The contribution from agricultural waste fires was likely a lower bound because our approach for measuring burned area could not detect all of these relatively small fires. Total carbon emissions were on average 13% lower than in our previous (GFED2) work. For reduced trace gases such as CO and CH4, deforestation, degradation, and peat fires were more important contributors because of higher emissions of reduced trace gases per unit carbon combusted compared to savanna fires. Carbon emissions from tropical deforestation, degradation, and peatland fires were on average 0.5 Pg C year−1. The carbon emissions from these fires may not be balanced by regrowth following fire. Our results provide the first global assessment of the contribution of different sources to total global fire emissions for the past decade, and supply the community with an improved 13-year fire emissions time series.


  • Over the last decade, the role of fire in shaping the environment and atmosphere has been increasingly appreciated (e.g., Langmann et al, 2009; Bowman et al, 2009)

  • Results of the Monte Carlo simulation indicated that globally, uncertainties were around 20% (1σ ) for annual carbon estimates during the MODerate resolution Imaging Spectroradiometer (MODIS) era (2001–2009) and somewhat higher during the years before when burned area was derived from Along-Track Scanning Radiometer (ATSR) and Visible and Infrared Scanner (VIRS) hot spots (Fig. 14)

  • One factor that had a major impact on the spatial distribution of the uncertainties was whether mapped burned area was available, or whether burned area estimates were derived from fire hot spot – burned area relations

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The role of fire in shaping the environment and atmosphere has been increasingly appreciated (e.g., Langmann et al, 2009; Bowman et al, 2009). Fires contribute significantly to the budgets of several trace gases and aerosols (Andreae and Merlet, 2001) and are one of the primary causes of interannual variability in the growth rate of several trace gases, including the greenhouse gases CO2 and CH4 (Langenfelds et al, 2002). Humans are known to have increased fire activity (Fearnside, 2005; Schultz et al, 2008; Field et al, 2009). Fire activity has increased in more remote regions due to humans (e.g., Mollicone et al, 2006). Climate change may lead to more frequent and intense fires if drought conditions in areas with abundant fuel loads become more severe (Kasischke et al, 1995; Westerling et al, 2006)

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