Observationally constrained global NOx and CO emissions variability reveals sources which contribute significantly to CO2 emissions

Abstract

Abstract Global high-resolution emission inventories of trace gases require refinement to align with ground-based observations, especially for extreme events and changing sources. This study utilizes two satellites to globally quantify NO2 and CO concentrations on daily to weekly scales and estimate emissions with uncertainty bounds, grid-by-grid, for regions with significant variability in 2010. These emissions demonstrate overall increased emissions and identify missing sources compared with various inventories. The NOx and CO emissions are 5.76 × 105–6.25 × 106 Mt/yr and 1.06 × 107–2.78 × 107 Mt/yr, representing a mean 200% and 130% increase. Significant emissions originate from typical and atypical sources, exhibiting short-to-medium-term variability, primarily driven by biomass burning and anthropogenic activities, with substantial redistribution and compression due to long-range transport. The extra CO emissions chemically decay into CO2, resulting in an increase in CO2 mass equivalent to 3.5% of CO2 emissions from Central Africa and 6.1% from Amazon, reflecting the importance of addressing CO from biomass burning.