GloCAB: Global Cropland Burned Area from Mid-2002 to 2020

Abstract. Burned area estimates are an essential component of inventory-based fire emission calculations, and any inaccuracies in those estimates propagate into the final emission outputs. While satellite-based global burned area and fire emission datasets (e.g. GFED, FireCCI51, and MCD64A1) are frequently cited within the scientific literature and used by a range of users from atmospheric and carbon modelers to policy-makers, they are generally not optimized for cropland burning – a quintessential small-fire type. Here we describe a new dataset (GloCAB; Global Cropland Area Burned) which represents the first attempt at a global cropland-focused burned area product. The GloCAB dataset provides global, monthly cropland burned area at 0.25° spatial resolution from July 2002 – December 2020. Crop-specific burned area conversion factors for several widespread burnable crops (winter wheat, spring wheat, maize, rice, and sugarcane) were calculated from extensively-mapped cropland reference regions spanning 190,650 fields over 5 different countries. We found global annual cropland burned area (2003 – 2020) ranged between 64 Mha (2018) and 102 Mha (2008) with an average of 81 Mha using our lower-bound estimates which are substantially higher than the annual average of 32 Mha in the MCD64A1 C6 product. Region-specific trend analysis found some areas with significant increasing trends (northwest India), while the heterogeneity of many other regions found no burned area trends. This cropland-focused burned area methodology is the first step toward improving the representation of global crop-residue burning emissions – an often overlooked small-fire source of trace gas and aerosol emissions within global fire emission inventories.