Global fire emissions and the contribution of deforestation, savanna, forest, agricultural, and peat fires (1997–2009)

Abstract

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 burned area estimates based on 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 Advanced Very High Resolution Radiometer (AVHRR) derived estimates of plant productivity during the same period. Average global fire carbon emissions were 2.0 Pg yr−1 with significant interannual variability during 1997–2001 (2.8 Pg yr−1 in 1998 and 1.6 Pg yr−1 in 2001). Emissions during 2002–2007 were relatively constant (around 2.1 Pg yr−1) before declining in 2008 (1.7 Pg yr−1) and 2009 (1.5 Pg yr−1) partly due to lower deforestation fire emissions in South America and tropical Asia. During 2002–2007, emissions were highly variable from year-to-year in many regions, including in boreal Asia, South America, and Indonesia, but these regional differences cancelled out at a global level. During the MODIS era (2001–2009), most fire 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. 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 yr−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.

Climate-driven ground-level ozone extreme in the fall over the Southeast United States

“…We used GFED4s to investigate the impact of fire emissions. GFED combines satellite information on fire activity and vegetation productivity to estimate burned areas (41) and fire emissions (42). The technique described in ref.…”

Asymmetrical Interannual Variation in Aerosol Optical Depth over the Tropics in Terms of Aerosol-Cloud Interaction

“…We investigated the interannual variation in the sources of aerosols over the Maritime Continent by using the Global Fire Emission Database version 3 (van der Werf et al 2010). The correlation coefficient between AOD and organic carbon was 0.94 (see Supplement 1), which indicated that the interannual variation in the sources of aerosols over the Maritime Continent corresponds to that in AOD, which is likely associated with surface conditions partly through the precipitation variations.…”

Fire Influences on Atmospheric Composition, Air Quality and Climate

“…These represent the amount of the chemical species released per mass of biomass burned and are typically obtained from measurement campaigns in biomass burning regions [11,21,22]. The largest gaseous non-CO 2 fire emissions are those of CO, which are a result of incomplete combustion, especially from smouldering peat fires [12]. Amongst the short-lived constituents emitted from fires, CO has the largest potential to impact atmospheric composition on large geographical scales (hemispheric or even global), due to its comparatively long lifetime of a few months.…”

“…The first is to estimate total fuel consumption as the product of the area burned and the fuel consumed per unit area. This approach is used for the series of Global Fire Emissions Database (GFED) products [12], Fire Inventory from NCAR (FINN) [13] and, for particulate emissions, the Fire Locating and Modeling of Burning Emissions inventory (FLAMBE) [14].…”

“…Carbon dioxide (CO 2 ), carbon monoxide (CO), nitrogen oxides (NO x ) and non-methane volatile organic compounds (NMVOCs) are the most important emitted gases, while black carbon (BC) and organic carbon (OC) are the most important aerosol species [10][11][12]. CO 2 emissions can have important implications for CO 2 concentrations and understanding the carbon cycle but do not directly affect atmospheric chemistry or contribute to air quality degradation.…”