Tropical savanna and forest fires are important sources of air pollutants to the global atmosphere. In this talk, I focus on our recent efforts to quantify the magnitude and variability of tropical fire-driven atmospheric emissions using remotely sensed datasets of active fires and burned area in combination with a global biogeochemical model. Satellite based measurements of tropospheric carbon monoxide enable us to characterize the accuracy of the resulting inventory. Finally, I will discuss internannual variability in carbon emissions associated with deforestation in the Amazon and Indonesia in recent years, and explore the causes of these variations.