Fire emission abatement potential by shifting fire regimes in global savannas: a reassessment using the fifth version of the Global Fire Emissions Database (GFED5)

Background Subtropical savannas account for about 70% of the world’s annual burned area (BA). A key fire management strategy in these areas involves controlled, low-intensity fires earlier in the dry season to prevent high-intensity fires later in the season. This method leads to smaller, patchier fires with lower fuel consumption (FC) than late-season fires, reducing greenhouse gas emissions. Aims and methods We aim to quantify emissions and potential emission abatement from prescribed burning for global savannas by extrapolating fire seasonality shifts reported for existing projects. This is based on Global Fire Emissions Database version 5 (GFED5) which offers improved modeling of small fire extent, emission factors (EFs) and FC dynamics. Key results and conclusions The highest potential abatement was located in high-rainfall savannas in Southern Africa, South America and Central America. GFED5 emissions from savannas were 749 Tg carbon dioxide-equivalent (CO2-eq) per year. Results indicate that 66–363 Tg CO2-equivalent emissions, or 9–48% of the annual emissions could be abated through early dry season (EDS)-prescribed burning, mostly through the reduction of annual BA. Our analysis indicates that the indirect warming from carbon monoxide (CO) emissions from savanna fires may be larger than the combined impact of methane (CH4) and nitrous oxide (N2O).