Methane Emissions From Wildfires: Trends and Anomalies

Abstract

Wildfires emit smoke particles and trace gases including greenhouse gases into the atmosphere, impacting the environment and leading to detrimental impacts on human health and economy. The estimation of spatially and temporally resolved methane emissions from biomass burning (BB) provides critical information in developing measurement‐informed methane inventories. The use of satellite active fire products (fire radiative power) is an effective pathway to investigate wildfire emissions around the world. In this study, the Global BB Emissions Product‐eXtended algorithm is employed to estimate long‐term temporal variation and geographic distribution of methane emissions from BB using satellite observations from the Moderate Resolution Imaging Spectroradiometer and the Visible Infrared Imaging Radiometer Suite. Globally, on average about 19 Megatonnes of BB methane are released to the atmosphere every year, nearly half of it originating from Africa, where BB represents a significant proportion of the total methane emissions. Our findings show that methane emissions from wildfires are substantial and can exceed other source sectors during extreme wildfire events, negating gains from years of emission reductions from anthropogenic sources. The contribution of fires to the methane budget is significant for regions with intense fire activities. Effective wildfire prevention and management could be beneficial to rapidly reduce methane emissions from BB.